Gestational age

1.1.1.

Offer women with a twin or triplet pregnancy a first trimester ultrasound scan to estimate gestational age and determine chorionicity and amnionicity (ideally, these should all be performed at the same scan; see the recommendations on determining chorionicity and amnionicity and assigning nomenclature). See the recommendations on screening for chromosomal conditions. [2011, amended 2019]

1.1.2.

Estimate gestational age from the largest baby in a twin or triplet pregnancy to avoid the risk of estimating it from a baby with early growth pathology. [2011]

Chorionicity and amnionicity

1.1.3.

Determine chorionicity and amnionicity at the time of detecting a twin or triplet pregnancy by ultrasound using:

• the number of placental masses
• the presence of amniotic membrane(s) and membrane thickness
• the lambda or T-sign. [2011, amended 2019]

1.1.4.

Assign nomenclature to babies (for example, upper and lower, or left and right) in a twin or triplet pregnancy, and document this clearly in the woman's notes to ensure consistency throughout pregnancy. [2011]

1.1.5.

If a woman with a twin or triplet pregnancy presents after 14+0 weeks, determine chorionicity and amnionicity at the earliest opportunity by ultrasound using all of the following:

• the number of placental masses
• the presence of amniotic membrane(s) and membrane thickness
• the lambda or T-sign
• discordant fetal sex. [2011, amended 2019]

1.1.6.

If it is not possible to determine chorionicity or amnionicity by ultrasound at the time of detecting the twin or triplet pregnancy, seek a second opinion from a senior sonographer or refer the woman to a healthcare professional who is competent in determining chorionicity and amnionicity by ultrasound scan as soon as possible. [2011, amended 2019]

1.1.7.

If it is difficult to determine chorionicity, even after referral (for example, because the woman has booked late in pregnancy), manage the pregnancy as a monochorionic pregnancy until proven otherwise. [2011]

1.1.8.

Provide regular training so that sonographers can identify the lambda or T-sign accurately and confidently. Less experienced sonographers should have support from senior colleagues. [2011]

1.1.9.

Training should cover ultrasound scan measurements needed for women who book after 14+0 weeks and should emphasise that the risks associated with twin and triplet pregnancy are determined by chorionicity and not zygosity. [2011]

1.1.10.

Conduct regular clinical audits to evaluate the accuracy of determining chorionicity and amnionicity. [2011, amended 2019]

1.1.11.

If transabdominal ultrasound scan views are poor because of a retroverted uterus or a high BMI, use a transvaginal ultrasound scan to determine chorionicity and amnionicity. [2011, amended 2019]

1.1.12.

Do not use 3-dimensional (3D) ultrasound scans to determine chorionicity and amnionicity. [2011, amended 2019]

1.1.13.

Networks should agree care pathways for managing all twin and triplet pregnancies to ensure that each woman has a care plan in place that is appropriate for the chorionicity and amnionicity of her pregnancy. [2011, amended 2019]

Information and emotional support

1.2.1.

Explain sensitively the aims and possible outcomes of all screening and diagnostic tests to women with a twin or triplet pregnancy to minimise their anxiety. [2011]

Diet, lifestyle and nutritional supplements

1.2.2.

Give women with a twin or triplet pregnancy the same advice about diet, lifestyle and nutritional supplements as in routine antenatal care (see NICE'S guideline on antenatal care). [2011]

1.2.3.

Be aware of the higher incidence of anaemia in women with a twin or triplet pregnancy compared with women with a singleton pregnancy. [2011]

1.2.4.

Perform a full blood count at 20 to 24 weeks to identify women with a twin or triplet pregnancy who need early supplementation with iron or folic acid (this is in addition to the test for anaemia at the routine booking appointment recommended in NICE's guideline on antenatal care). Repeat at 28 weeks as in routine antenatal care. [2011]

Antenatal care

1.3.1.

Antenatal clinical care for women with a twin or triplet pregnancy should be provided by a nominated multidisciplinary team consisting of:

• a core team of named specialist obstetricians, specialist midwives and sonographers, all of whom have experience and knowledge of managing twin and triplet pregnancies
• an enhanced team for referrals, which should include:

  –

  a perinatal mental health professional

  –

  a women's health physiotherapist

  –

  an infant feeding specialist

  –

  a dietitian. [2011, amended 2019]

1.3.2.

Members of the enhanced team should have experience and knowledge relevant to twin and triplet pregnancies. [2011]

1.3.3.

Do not routinely refer all women with a twin or triplet pregnancy to the enhanced team but base the decision to refer on each woman's needs. [2011]

1.3.4.

Coordinate clinical care for women with a twin or triplet pregnancy to:

• minimise the number of hospital visits
• provide care as close to the woman's home as possible
• provide continuity of care within and between hospitals and the community. [2011]

1.3.5.

The core team should offer information and emotional support specific to twin and triplet pregnancies at their first contact with the woman and provide ongoing opportunities for further discussion and advice including:

• antenatal and postnatal mental health and wellbeing
• antenatal nutrition (see the recommendation on giving advice in the section on diet, lifestyle and nutritional supplements)
• the risks, symptoms and signs of preterm labour and the potential need for corticosteroids for fetal lung maturation
• likely timing of birth (see the section on timing of birth) and possible modes of birth (see the section on mode of birth)
• breastfeeding
• parenting. [2011]

Intrapartum care

1.3.6.

Intrapartum care for women with a twin or triplet pregnancy should be provided by a multidisciplinary team of obstetricians and midwives who have experience and knowledge of managing twin and triplet pregnancies in the intrapartum period. [2019]

Schedule of specialist antenatal appointments

The schedule of specialist appointments is also shown as part of a multiple pregnancy antenatal care resource produced by Twins Trust and endorsed by NICE.

Dichorionic diamniotic twin pregnancy

1.3.7.

Offer women with an uncomplicated dichorionic diamniotic twin pregnancy at least 8 antenatal appointments with a healthcare professional from the core team. At least 2 of these appointments should be with the specialist obstetrician.

• Combine appointments with scans when crown–rump length measures from 45.0 mm to 84.0 mm (at approximately 11+2 weeks to 14+1 weeks) and then at estimated gestations of 20, 24, 28, 32 and 36 weeks.
• Offer additional appointments without scans at 16 and 34 weeks. [2011, amended 2019]

Monochorionic diamniotic twin pregnancy

1.3.8.

Offer women with an uncomplicated monochorionic diamniotic twin pregnancy at least 11 antenatal appointments with a healthcare professional from the core team. At least 2 of these appointments should be with the specialist obstetrician.

• Combine appointments with scans when crown–rump length measures from 45.0 mm to 84.0 mm (at approximately 11+2 weeks to 14+1 weeks) and then at estimated gestations of 16, 18, 20, 22, 24, 26, 28, 30, 32 and 34 weeks. [2011, amended 2019]

Triamniotic triplet pregnancy (trichorionic, dichorionic or monochorionic)

1.3.9.

Offer women with an uncomplicated trichorionic triamniotic triplet pregnancy at least 9 antenatal appointments with a healthcare professional from the core team. At least 2 of these appointments should be with the specialist obstetrician.

• Combine appointments with scans when crown–rump length measures from 45.0 mm to 84.0 mm (at approximately 11+2 weeks to 14+1 weeks) and then at estimated gestations of 20, 24, 26, 28, 30, 32 and 34 weeks.
• Offer an additional appointment without a scan at 16 weeks. [2011, amended 2019]

1.3.10.

Offer women with a dichorionic triamniotic or monochorionic triamniotic triplet pregnancy at least 11 antenatal appointments with a healthcare professional from the core team. At least 5 of these appointments should be with the specialist obstetrician.

• Combine appointments with scans when crown–rump length measures from 45.0 mm to 84.0 mm (at approximately 11+2 weeks to 14+1 weeks) and then at estimated gestations of 16, 18, 20, 22, 24, 26, 28, 30, 32 and 34 weeks. [2011, amended 2019]

Twin and triplet pregnancies with a shared amnion

1.3.11.

Offer women with a twin or triplet pregnancy involving a shared amnion individualised care from a consultant in a tertiary level fetal medicine centre (see the recommendation on indications for referral to a tertiary level fetal medicine centre). [2011]

Information about screening

1.4.1.

A healthcare professional with experience of caring for women with twin and triplet pregnancies should offer information and counselling to women before and after every screening test. [2011]

1.4.2.

Inform women with a twin or triplet pregnancy about the complexity of decisions they may need to make depending on the outcomes of screening, including different options according to the chorionicity and amnionicity of the pregnancy. [2011, amended 2019]

Screening for chromosomal conditions

Screening for structural abnormalities

1.4.9.

Offer screening for structural abnormalities (such as cardiac abnormalities) in twin and triplet pregnancies as in routine antenatal care; see NICE's guideline on antenatal care and the NHS fetal anomaly screening programme. [2011]

1.4.10.

Consider scheduling ultrasound scans in twin and triplet pregnancies at a slightly later gestational age than in singleton pregnancies and be aware that the scans will take longer to perform. [2011]

1.4.11.

Allow 45 minutes for the anomaly scan in twin and triplet pregnancies (as recommended by FASP). [2011]

1.4.12.

Allow 30 minutes for growth scans in twin and triplet pregnancies. [2011]

Screening for preterm birth

Also see the section on preventing preterm birth.

1.4.13.

Explain to women or pregnant people and their family members or carers (as appropriate) that:

• they have a higher risk of spontaneous preterm birth (see the section on timing of birth) than women or pregnant people with a singleton pregnancy and
• this risk is further increased if they have other risk factors, such as a spontaneous preterm birth in a previous pregnancy or they are found to have a short cervix on cervical length screening. [2019, amended 2024]

1.4.14.

Do not use fetal fibronectin testing alone to predict the risk of spontaneous preterm birth in twin and triplet pregnancy. [2019]

1.4.15.

Do not use home uterine activity monitoring to predict the risk of spontaneous preterm birth in twin and triplet pregnancy. [2019]

Screening for fetal growth restriction and feto-fetal transfusion syndrome in the first trimester

1.4.16.

Do not offer women with a twin or triplet pregnancy screening for fetal growth restriction or feto-fetal transfusion syndrome in the first trimester. [2019]

Diagnostic monitoring for fetal growth restriction in dichorionic twin and trichorionic triplet pregnancies

1.4.17.

Do not use abdominal palpation or symphysis–fundal height measurements to monitor for fetal growth restriction in a dichorionic twin or trichorionic triplet pregnancy. [2019]

1.4.18.

At each ultrasound scan from 24 weeks, offer women with a dichorionic twin or trichorionic triplet pregnancy diagnostic monitoring for fetal weight discordance using 2 or more biometric parameters and amniotic fluid levels. To assess amniotic fluid levels, measure the deepest vertical pocket (DVP) on either side of the amniotic membrane. [2019]

1.4.19.

Continue monitoring for fetal weight discordance at intervals that do not exceed:

• 28 days for women with a dichorionic twin pregnancy
• 14 days for women with a trichorionic triplet pregnancy. [2019]

1.4.20.

Calculate and document estimated fetal weight (EFW) discordance for dichorionic twins using the formula below [2019]:

([EFW larger fetus − EFW smaller fetus] ÷ EFW larger fetus) × 100

1.4.21.

Calculate and document EFW discordance for trichorionic triplets using the formula below [2019]:

([EFW largest fetus − EFW smallest fetus] ÷ EFW largest fetus) × 100

and

([EFW largest fetus − EFW middle fetus] ÷ EFW largest fetus) × 100

1.4.22.

Increase diagnostic monitoring in the second and third trimesters to at least weekly, and include Doppler assessment of the umbilical artery flow for each baby, if:

• there is an EFW discordance of 20% or more and/or
• the EFW of any of the babies is below the 10th centile for gestational age. [2019]

1.4.23.

Refer women with a dichorionic twin or trichorionic triplet pregnancy to a tertiary level fetal medicine centre if there is an EFW discordance of 25% or more and the EFW of any of the babies is below the 10th centile for gestational age because this is a clinically important indicator of selective fetal growth restriction. [2019]

Diagnostic monitoring for complications of monochorionicity in twin and triplet pregnancy

A monochorionic twin or triplet pregnancy is one in which any of the babies share a placenta and a chorionic (outer) membrane. This includes monochorionic twins and dichorionic and monochorionic triplets.

1.4.24.

Offer women simultaneous monitoring for feto-fetal transfusion syndrome, fetal growth restriction and advanced-stage twin anaemia polycythaemia sequence (TAPS) at every ultrasound assessment to monitor effectively for all complications of monochorionicity. Explain that the relative likelihood of each complication changes with advancing gestation but that they can all occur at any gestational age. [2019]

Corticosteroids

1.5.7.

Inform women with a twin or triplet pregnancy of their increased risk of preterm birth (see the recommendation explaining screening for preterm birth to women and their family members in the section on screening for preterm birth) and about the benefits of targeted corticosteroids. [2011]

1.5.8.

Do not use single or multiple untargeted (routine) courses of corticosteroids in twin or triplet pregnancy. Inform women that there is no benefit in using untargeted administration of corticosteroids. [2011]

Hypertension

1.6.1.

Measure blood pressure and test urine for proteinuria to screen for hypertensive disorders at each antenatal appointment in a twin and triplet pregnancy in line with NICE's guideline on antenatal care. [2011]

1.6.2.

Advise women with a twin or triplet pregnancy to take low-dose aspirin daily from 12 weeks until the birth of the babies if they have 2 or more of the risk factors specified in the section on antiplatelet agents in NICE's guideline on hypertension in pregnancy. [2011, amended 2019]

In September 2019, this was an off-label use of aspirin. See NICE's information on prescribing medicines.

Antenatal information for women

1.9.1.

Explain to women with a twin pregnancy that about 60 in 100 twin pregnancies result in spontaneous birth before 37 weeks. [2019]

1.9.2.

Explain to women with a triplet pregnancy that about 75 in 100 triplet pregnancies result in spontaneous birth before 35 weeks. [2019]

1.9.3.

Explain to women with a twin or triplet pregnancy that spontaneous preterm birth and planned preterm birth are associated with an increased risk of admission to a neonatal unit. [2019]

1.9.4.

Explain to women with an uncomplicated dichorionic diamniotic twin pregnancy that:

• planned birth from 37+0 weeks does not appear to be associated with an increased risk of serious neonatal adverse outcomes and
• continuing the pregnancy beyond 37+6 weeks increases the risk of fetal death. [2019]

1.9.5.

Explain to women with an uncomplicated monochorionic diamniotic twin pregnancy that:

• planned birth from 36+0 weeks does not appear to be associated with an increased risk of serious neonatal adverse outcomes and
• continuing the pregnancy beyond 36+6 weeks increases the risk of fetal death. [2019]

1.9.6.

Explain to women with an uncomplicated monochorionic monoamniotic twin pregnancy that planned birth between 32+0 and 33+6 weeks does not appear to be associated with an increased risk of serious neonatal adverse outcomes. Also explain that:

• these babies will usually need to be admitted to the neonatal unit and have an increased risk of respiratory problems
• continuing the pregnancy beyond 33+6 weeks increases the risk of fetal death. [2019]

1.9.7.

Explain to women with an uncomplicated trichorionic triamniotic or dichorionic triamniotic triplet pregnancy that continuing the pregnancy beyond 35+6 weeks increases the risk of fetal death. [2019]

1.9.8.

Explain to women with a monochorionic triamniotic triplet pregnancy or a triplet pregnancy that involves a shared amnion that the timing of birth will be decided and discussed with each woman individually. [2019]

When to offer planned birth

1.9.9.

Offer planned birth at 37 weeks to women with an uncomplicated dichorionic diamniotic twin pregnancy. [2019]

1.9.10.

Offer planned birth as follows, after a course of antenatal corticosteroids has been considered (see the section on maternal corticosteroids in NICE's guideline on preterm labour and birth):

• at 36 weeks for women with an uncomplicated monochorionic diamniotic twin pregnancy
• between 32+0 and 33+6 weeks for women with an uncomplicated monochorionic monoamniotic twin pregnancy
• at 35 weeks for women with an uncomplicated trichorionic triamniotic or dichorionic triamniotic triplet pregnancy. [2019]

1.9.11.

Offer an individual assessment to determine the timing of planned birth in women with any of the following:

• a complicated twin or triplet pregnancy
• a monochorionic triamniotic triplet pregnancy
• a triplet pregnancy that involves a shared amnion. [2019]

1.9.12.

For women who decline planned birth at the timing recommended in recommendations 1.9.9 and 1.9.10, offer weekly appointments with the specialist obstetrician. At each appointment, offer an ultrasound scan and perform assessments of amniotic fluid level and Doppler of the umbilical artery flow for each baby in addition to fortnightly fetal growth scans. [2019]

Twin pregnancy: dichorionic diamniotic or monochorionic diamniotic

1.10.1.

Explain to women with an uncomplicated twin pregnancy planning their mode of birth that planned vaginal birth and planned caesarean section are both safe choices for them and their babies if all of the following apply:

• the pregnancy remains uncomplicated and has progressed beyond 32 weeks
• there are no obstetric contraindications to labour
• the first baby is in a cephalic (head-first) presentation
• there is no significant size discordance between the twins. [2019]

1.10.2.

Explain to women with an uncomplicated twin pregnancy that for women giving birth after 32 weeks (see recommendation 1.10.1):

• more than a third of women who plan a vaginal birth go on to have a caesarean section
• almost all women who plan a caesarean section do have one, but a few women have a vaginal birth before caesarean section can be carried out
• a small number of women who plan a vaginal birth will need an emergency caesarean section to deliver the second twin after vaginal birth of the first twin. [2019]

1.10.3.

Offer caesarean section to women if the first twin is not cephalic at the time of planned birth. [2019]

1.10.4.

Offer caesarean section to women in established preterm labour between 26 and 32 weeks if the first twin is not cephalic. [2019]

1.10.5.

Offer an individualised assessment of mode of birth to women in suspected, diagnosed or established preterm labour before 26 weeks. Take into account the risks of caesarean section (see NICE's guideline on preterm labour and birth) and the chance of survival of the babies. [2019]

Twin pregnancy: monochorionic manoamniotic

1.10.6.

Offer a caesarean section to women with a monochorionic monoamniotic twin pregnancy:

• at the time of planned birth (between 32+0 and 33+6 weeks) or
• after any complication is diagnosed in her pregnancy requiring earlier delivery or
• if she is in established preterm labour, and gestational age suggests there is a reasonable chance of survival of the babies (unless the first twin is close to vaginal birth and a senior obstetrician advises continuing to vaginal birth). [2019]

Triplet pregnancy

1.10.7.

Offer a caesarean section to women with a triplet pregnancy:

• at the time of planned birth (35 weeks) or
• after any complication is diagnosed in her pregnancy requiring earlier delivery or
• if she is in established preterm labour, and gestational age suggests there is a reasonable chance of survival of the babies. [2019]

Antenatal information for women

1.11.1.

By 28 weeks of pregnancy, discuss continuous cardiotocography with women with a twin pregnancy and their family members or carers (as appropriate) and address any concerns. Explain that the recommendations on cardiotocography are based on evidence from women with a singleton pregnancy because there is a lack of evidence specific to twin pregnancy or preterm babies. [2019]

1.11.2.

Explain to the woman that continuous cardiotocography is used to monitor the babies' heartbeats and her labour contractions, and that:

• it allows simultaneous monitoring of both babies
• it might restrict her mobility
• normal traces show the babies are coping well with labour; if traces are not normal, there will be less certainty about the babies' condition
• it is normal to see changes to the fetal heart rate pattern during labour and this does not necessarily mean there is a problem
• findings from the cardiotocograph are used to help make decisions during labour and birth, but these will also be based on her wishes, her condition and that of her babies. [2019]

Intrapartum monitoring

1.11.3.

Offer continuous cardiotocography to women with a twin pregnancy who are in established labour and are more than 26 weeks pregnant. [2019]

1.11.4.

Perform a portable ultrasound scan when established labour starts, to confirm which twin is which, the presentation of each twin, and to locate the fetal hearts. [2019]

1.11.5.

Do not offer intermittent auscultation to women with a twin pregnancy who are in established labour and are more than 26 weeks pregnant. [2019]

1.11.6.

For women between 23+0 and 25+6 weeks of pregnancy who are in established labour, involve a senior obstetrician in discussions with the woman and her family members or carers about how to monitor the fetal heart rates. [2019]

1.11.7.

When carrying out cardiotocography:

• use dual channel cardiotocography monitors to allow simultaneous monitoring of both fetal hearts
• document on the cardiotocograph and in the clinical records which cardiotocography trace belongs to which baby
• monitor the maternal pulse electronically and display it simultaneously on the same cardiotocography trace. [2019]

1.11.8.

Consider separating the fetal heart rates by 20 beats/minute if there is difficulty differentiating between them. [2019]

1.11.9.

Classify and interpret cardiotocography in line with the section on the use of cardiotocography for monitoring during labour in the NICE guideline on fetal monitoring in labour, taking into account that:

• twin pregnancy should be considered a fetal clinical risk factor when classifying a cardiotocography trace as 'abnormal' versus 'non-reassuring'
• fetal scalp stimulation should not be performed in twin pregnancy to gain reassurance after a cardiotocography trace that is categorised as 'pathological'. [2019]

Reviewing cardiotocography

1.11.10.

Carry out systematic assessments of both cardiotocographs at least hourly, and more frequently if there are concerns. [2019]

1.11.11.

At each systematic assessment, document which cardiotocography trace belongs to which baby. [2019]

1.11.12.

Be aware of the possibility of monitoring the same baby twice. At each cardiotocography review, ensure that twin synchronicity is not occurring. [2019]

Management based on cardiotocography

1.11.13.

If abdominal monitoring is unsuccessful or there are concerns about synchronicity of the fetal hearts:

• involve a senior obstetrician and senior midwife
• apply a fetal scalp electrode to the first baby (only after 34 weeks and if there are no contraindications) while continuing abdominal monitoring of the second baby
• perform a bedside ultrasound scan to confirm both fetal heart rates
• if monitoring remains unsatisfactory, consider a caesarean section. [2019]

1.11.14.

If the cardiotocograph trace is categorised as 'suspicious' in the first baby during established labour:

• involve the senior obstetrician and senior midwife
• correct any reversible causes
• apply a fetal scalp electrode to the first baby (only after 34 weeks and if there are no contraindications) while continuing abdominal monitoring of the second baby. [2019]

1.11.15.

If the cardiotocograph trace is categorised as 'pathological' in the first baby during established labour:

• involve the senior obstetrician and senior midwife
• discuss with the woman and her family members or carers the possible use of fetal blood sampling of the first baby from 34 weeks if the benefits are likely to outweigh the potential risks. [2019]

1.11.16.

When offering fetal blood sampling in twin pregnancy, discuss with the woman and her family members or carers that if a blood sample cannot be obtained then she is likely to need a caesarean section. [2019]

1.11.17.

If the results of fetal blood sampling are not available within 20 minutes or fetal blood sampling is contraindicated, offer an immediate caesarean section to women with a twin pregnancy. [2019]

1.11.18.

If the cardiotocograph trace is categorised as 'pathological' in the first baby during the second stage of labour:

• involve the senior obstetrician and senior midwife
• assess whether an assisted vaginal birth is an option
• if vaginal birth is not an option or cannot be achieved within 20 minutes, offer an immediate caesarean section. [2019]

1.11.19.

If the cardiotocograph trace of the second baby is categorised as 'suspicious' or 'pathological' during established labour before the first baby is born:

• involve the senior obstetrician and senior midwife
• if vaginal birth of the second baby cannot be achieved within 20 minutes, discuss performing a caesarean section with the woman and her family members or carers. [2019]

1.11.20.

After the birth of the first baby:

• continue to monitor the second baby using cardiotocography
• if there is 'suspicious' or 'pathological' cardiotocography, and vaginal birth cannot be achieved within 20 minutes, discuss performing a caesarean section with the woman and her family members or carers. [2019]

1.11.21.

After the birth of both babies, consider double clamping the cord to allow umbilical cord blood gases to be sampled. Ensure that the samples are correctly labelled for each baby. [2019]

Assessing risk

1.13.1.

Start assessing the risk of postpartum haemorrhage in women with a twin or triplet pregnancy in the antenatal period and continue throughout labour and the third stage (see the section on risk factors for postpartum haemorrhage in NICE'S guideline on intrapartum care). [2019]

1.13.2.

Offer each woman an individualised assessment of her risk of postpartum haemorrhage and explain that multiple pregnancy is a risk factor for increased blood loss at delivery. [2019]

Management

1.13.3.

By 28 weeks of pregnancy, discuss options for managing the third stage of labour with women with a twin or triplet pregnancy. [2019]

1.13.4.

Do not offer physiological management of the third stage to women with a twin or triplet pregnancy. [2019]

1.13.5.

Offer women with a twin or triplet pregnancy active management of the third stage. Explain that it is associated with a lower risk of postpartum haemorrhage and/or blood transfusion. [2019]

1.13.6.

Consider active management of the third stage with additional uterotonics for women who have 1 or more risk factors (in addition to a twin or triplet pregnancy) for postpartum haemorrhage. [2019]

Blood transfusion

1.13.7.

By 28 weeks of pregnancy, discuss with women with a twin or triplet pregnancy the potential need for blood transfusion, including the need for intravenous access. Document this discussion in the woman's notes. [2019]

1.13.8.

At the start of established labour in women with a twin or triplet pregnancy:

• ensure that intravenous access is available so that prompt blood transfusion and intravenous fluids can be given if needed
• take a maternal blood sample for a full blood count and group and save. [2019]

1.13.9.

Ensure that the appropriate blood transfusion is available for urgent administration. [2019]

1. Screening to detect twin anaemia polycythaemia sequence

What is the most accurate prenatal screening marker for TAPS, including middle cerebral artery peak systolic velocity (MCA-PSV)? [2019]

2. Information and support

Does additional information and emotional support improve outcomes in twin and triplet pregnancies? [2011]

3. Specialist care

Does specialist antenatal care for women with twin and triplet pregnancies improve outcomes for women and their babies? [2011]

4. Indications for referral to a tertiary level fetal medicine centre

What is the incidence of monochorionic monoamniotic twin and triplet pregnancies, and what clinical management strategies are most effective in such pregnancies? [2011]

5. Progesterone in preventing spontaneous preterm birth in twin and triplet pregnancies

What is the clinical and cost effectiveness of progesterone in preventing spontaneous preterm birth in women or pregnant people with twin and triplet pregnancies and a history of previous preterm birth? [2024]

6. Gestational age

How should gestational age be estimated in twin and triplet pregnancies? [2011]

7. Chorionicity

What is the most accurate method of determining chorionicity in twin and triplet pregnancies at different gestational ages, and how does operator experience affect the accuracy of different methods? [2011]

8. Nutritional supplements

Is dietary supplementation with vitamins or minerals, or dietary manipulation in terms of calorie intake, effective in twin and triplet pregnancies? [2011]

9. Diet and lifestyle advice

Is dietary advice specific to twin and triplet pregnancies effective in improving maternal and fetal health and wellbeing? [2011]

10. Screening for structural abnormalities

When and how should screening for structural abnormalities be conducted in twin and triplet pregnancies? [2011]

11. Hypertension

Which clinical factors, laboratory screening tests, and ultrasound tests are predictive of hypertensive disorders in twin and triplet pregnancies? [2011]

12. Untargeted corticosteroids

What is the clinical and cost effectiveness, and safety, of routine antenatal administration of a single course of corticosteroids for women with twin and triplet pregnancies who are not in labour and in whom labour and birth are not imminent? [2011]

13. Indications for referral to a tertiary level fetal medicine centre

What is the clinical and cost effectiveness of referral to tertiary level fetal medicine centres for twin and triplet pregnancies complicated by discordant fetal growth, discordant fetal anomaly or discordant fetal death? [2011]

Why the committee made the recommendation

The committee recognised that the core multidisciplinary team recommended by the previous guideline (see recommendation 1.3.1) provides care during the antenatal period and would not be the same team providing intrapartum care. Because intrapartum care was added to the guideline update, they made a recommendation to clarify that healthcare professionals supporting women when they are giving birth should also have knowledge and experience in multiple pregnancy.

How the recommendation might affect practice

The recommendation reinforces current practice.

Return to recommendation

Why the committee made the recommendations

Since the 2011 guideline, the National Screening Committee's recommendations on screening for fetal chromosomal conditions have been published and have been implemented by the NHS fetal anomaly screening programme (FASP). These apply to women with both singleton and twin pregnancies, so the 2011 recommendations were replaced by a cross reference to this screening programme. The committee recognised that no current guidance exists for triplets so they retained a recommendation on triplets from the 2011 guideline. However, based on their expertise they decided this existing recommendation would apply only to screening in trichorionic triplets so they made an additional recommendation about dichorionic and monochorionic triplet pregnancies. Because of the complexity of screening these types of triplet pregnancies, this screening should only be carried out after referral to a tertiary level fetal medicine centre.

How the recommendations might affect practice

The recommendations reinforce current best practice.

Return to recommendations

Why the committee made the recommendations

The committee agreed, based on their experience and expertise, that women and pregnant people should be given information about the higher risk of preterm birth in twin and triplet pregnancy compared with singleton pregnancy, and about factors that may further increase this risk.

The committee retained the existing 2011 recommendations that fetal fibronectin testing and home uterine activity monitoring should not be used to predict the risk of spontaneous preterm birth because there was still no evidence suggesting they were accurate.

How the recommendations might affect practice

The recommendations reinforce current best practice.

Return to recommendations

Why the committee made the recommendation

How the recommendation might affect practice

The recommendation reinforces current practice.

Return to recommendations

Why the committee made the recommendations

Based on evidence which showed that abdominal palpation and symphysis–fundal height were not accurate measurements to diagnose fetal growth restriction, the committee recommended that these should not be used.

Fetal growth restriction is associated with perinatal mortality, morbidity and preterm birth. The committee agreed that monitoring using ultrasound scanning is essential to identify women in this high-risk group.

How the recommendations might affect practice

These recommendations are largely reinforcing current practice in twin pregnancy and should have a minimal impact on local ultrasound resourcing. They are consistent with other national and international guidance.

The recommendations to monitor all women with a triplet pregnancy at no more than 14-day intervals (irrespective of chorionicity) are a change in practice, particularly for women with a trichorionic triamniotic pregnancy. For these women, previous recommendations suggested 4-weekly scans. However, the change is justified because all types of triplet pregnancy are at high risk of fetal growth restriction. The recommendation should not have a significant impact on clinical resources because of the low number of women with a triplet pregnancy.

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Why the committee made the recommendations

The committee agreed that feto-fetal transfusion syndrome is difficult to detect using amniotic fluid discordance before 16 weeks of pregnancy. After this stage, amniotic fluid levels have increased and differences between them can be used to diagnose feto-fetal transfusion syndrome. Monitoring fortnightly from 16 weeks should ensure that feto-fetal transfusion syndrome is diagnosed as early as possible. The committee decided based on their expertise, and on limited evidence from studies that conducted diagnostic scans after 24 weeks, that continuing fortnightly monitoring until birth would improve outcomes for women who develop feto-fetal transfusion syndrome later in pregnancy (although it is less common after 26 weeks). The committee also agreed that offering women with a monochorionic pregnancy scans at 14-day intervals means that the woman can be monitored efficiently for all the complications in recommendation 1.4.24 at each scan.

To support this frequency of monitoring, the committee also increased the number of reviews by the specialist obstetrician from at least 2 (in the 2011 guideline) to at least 5 for dichorionic and monochorionic triamniotic triplet pregnancies (recommendation 1.3.10). Dichorionic triamniotic triplets have an increased risk of adverse outcomes compared with monochorionic diamniotic twins if feto-fetal transfusion occurs. The risk of complications of monochorionicity, and of adverse outcomes if complications occur, is higher in triplets than in twins. More frequent review by the specialist obstetrician would ensure optimal critical assessment of ultrasound findings (including findings related to feto-fetal transfusion syndrome) and any need for more frequent monitoring.

The committee agreed that making sure the amniotic membrane is visible in the scan reduces the chance of measuring the same sac twice in error and improves accuracy in identifying a difference between the babies' amniotic fluid levels.

Based on their knowledge and experience, the committee agreed that women should be referred immediately to a tertiary level fetal medicine centre when differences in amniotic fluid levels meet the criteria for diagnosing feto-fetal transfusion syndrome. The clinical course of feto-fetal transfusion syndrome can be unpredictable so this would allow prompt assessment and early intervention. They also agreed that when differences in amniotic fluid levels are measured that do not yet meet the threshold for feto-fetal transfusion syndrome, women should be seen by their named specialist obstetrician for multiple pregnancy and offered more frequent monitoring, using Doppler assessment to help detect feto-fetal transfusion syndrome as early as possible.

How the recommendations might affect practice

Monitoring for feto-fetal transfusion syndrome from 16 weeks of pregnancy until birth is a change to current practice, in which monitoring is only carried out until week 24. Early detection would enable prompt management, and this would outweigh the cost of additional ultrasound.

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Why the committee made the recommendations

Based on evidence which showed that abdominal palpation and symphysis–fundal height were not accurate measurements to diagnose fetal growth restriction, the committee recommended that these should not be used.

Fetal growth restriction is associated with perinatal mortality, morbidity and preterm birth. The committee agreed that monitoring using ultrasound scanning is essential to identify women in this high-risk group.

How the recommendations might affect practice

These recommendations are largely reinforcing current practice in twin pregnancy and should have a minimal impact on local ultrasound resourcing. They are consistent with other national and international guidance.

The recommendation to monitor all women with a triplet pregnancy at no more than 14-day intervals (irrespective of chorionicity) is a change in practice, particularly for women with a trichorionic triamniotic pregnancy. For these women, previous recommendations suggested 4-weekly scans. However, the change is justified because all types of triplet pregnancy are at high risk of fetal growth restriction. The recommendation should not have a significant impact on clinical resources because of the low number of women with a triplet pregnancy.

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Why the committee made the recommendations

There was limited evidence for screening and diagnostic monitoring for twin anaemia polycythaemia sequence (TAPS). The committee discussed, based on their expertise, that there is also limited evidence on the natural history of spontaneous TAPS and effective interventions for it in uncomplicated monochorionic pregnancies. They agreed that its incidence is likely to be low, so they could not recommend screening for it in women whose monochorionic pregnancy is uncomplicated.

The committee agreed that monitoring would be beneficial for women with the complications in recommendations 1.4.37 and 1.4.38. They recommended screening for TAPS in this population for 2 reasons:

• Complicated monochorionic pregnancies have an increased risk of fetal and neonatal death and morbidity. Diagnosing TAPS as a further complication is likely to influence how the woman's pregnancy is managed, including the timing of preterm birth.
• Advanced TAPS (stages 3 and 4) is associated with abnormal fetal umbilical artery and ductus venosus Doppler parameters, or signs of fetal cardiac failure in the anaemic baby. These can also occur in a number of other conditions, so the diagnosis of severe TAPS (either alone or as a comorbidity) may be missed if it is not specifically screened for.

The committee concluded that for women who have a pregnancy in which TAPS is a comorbid complication or is of advanced stage, the risk to the babies without diagnosis and intervention is likely to be greater than the potential harms of interventions. These include preterm birth or potential in-utero therapies, such as in-utero transfusion, in previable or extremely premature pregnancies.

The committee agreed that when TAPS is suspected, women should be referred to a tertiary level fetal medicine centre. They felt that the benefits of managing complicated monochorionic pregnancies in this setting would outweigh the potential disadvantages of inconvenience of travel and transfer to units away from home. The committee decided not to specify diagnostic criteria because they wanted to emphasise the importance of referral to a tertiary level referral centre when TAPS is suspected, so that decisions about further assessment and management can be made with each individual woman.

Given the limited evidence on the diagnostic accuracy of middle cerebral artery peak systolic velocity (MCA-PSV) for all types of monochorionic twins, regardless of complications, and uncertainties about the natural history of TAPS and its management, the committee decided to make a recommendation for research on screening to detect twin anaemia polycythaemia sequence to inform future guidance.

How the recommendations might affect practice

The recommendation may increase the number of assessments of women with complicated monochorionic pregnancies and referral for appropriate management. However, the committee agreed that any increase in referrals would be offset by the benefits of better detection and management of complicated monochorionic pregnancies.

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Why the committee made the recommendations

There was evidence of benefit for vaginal progesterone, with reduced preterm birth and reduced serious neonatal complications in women or pregnant people with a twin pregnancy and a short cervix (defined as 25 mm or less). There was no evidence of benefit for vaginal progesterone in women or pregnant people without a short cervix. There was also no evidence of benefit in those with or without a previous history of preterm birth, but this differed from the evidence for singleton pregnancies so the committee made a recommendation for research on progesterone in preventing spontaneous preterm birth in twin and triplet pregnancies. There was no evidence available for vaginal progesterone in women or pregnant people with a triplet pregnancy, but the committee agreed that it was reasonable to extrapolate on a physiological basis that benefits in twin pregnancies would also be seen in triplet pregnancies.

The committee noted that all the included studies had administered progesterone up to 34 weeks of pregnancy, so they included this in their recommendation, and that the majority of the studies had used a dose of vaginal progesterone 200 mg daily and that this was the dose approved in singleton pregnancies, so they recommended this dose.

The committee agreed that, to determine which women and pregnant people would benefit from treatment, it would be necessary to determine cervical length. Consequently, they made a recommendation to carry out a single cervical length scan in women and pregnant people with a twin or triplet pregnancy. The committee noted that in the evidence, cervical length scanning had been carried out before 20 weeks of pregnancy, but the committee were aware that cervical length scans were usually carried out between 16 and 20 weeks, so they included this range in their recommendation. This may also give units the flexibility to arrange the cervical length scan to coincide with other antenatal appointments and scans. However, the committee noted that sometimes cervical length measurement would be carried out later in pregnancy, for example if a woman or pregnant person presented with threatened preterm labour, or if they were late booking. In this case, the committee agreed to recommend that progesterone could be started up to 24 weeks (as there was evidence of benefit when started at this time).

The evidence for intramuscular progesterone in the prevention of spontaneous preterm birth showed it had no clinical benefit and, in some instances, had negative or unpleasant side effects, so it was not recommended.

The committee retained the existing 2011 recommendation that arabin pessary, bed rest, cervical cerclage and oral tocolytics should not be used routinely to prevent spontaneous preterm birth because there was still no evidence to support their use.

How the recommendations might affect practice

The committee noted that there would be a resource impact of carrying out cervical length screening for all women or pregnant people with a twin or triplet pregnancy and treating those with a short cervix with vaginal progesterone. However, the health economic modelling conducted for this review showed that carrying out cervical length screening of women or pregnant people with a twin or triplet pregnancy and offering vaginal progesterone to those with a short cervix would reduce preterm births and the associated neonatal morbidity and was a cost-effective use of NHS resources.

The recommendations for intramuscular progesterone, arabin pessary, bed rest, cervical cerclage and oral tocolytics reinforce current practice.

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Why the committee made the recommendations

The committee discussed the importance of providing care that is woman-centred, in which shared decision-making between the woman and her healthcare professional is essential. The committee agreed on the topics that need to be discussed with women to explain the available options and find out their wishes. Information needs to be tailored to each woman's pregnancy because some twin and triplet pregnancies carry more risks than others.

The committee acknowledged equality considerations for women who may have additional needs (such as needing an interpreter) in the context of providing information and communication. They cross-referred to NICE's guideline on patient experience in adult NHS services, which describes general good practice on how to do this.

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Why the committee made the recommendations

How the recommendations might affect practice

The recommendations clarify the timing of when women with a monochorionic monoamniotic pregnancy should be offered planned birth. Although this is a change from the 2011 guideline, it reinforces current practice.

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Why the committee made the recommendations

How the recommendations might affect practice

The recommendations largely reflect current practice. Supporting the woman's preferred mode of birth might increase the number of planned vaginal births, which may reduce costs. This is likely to be partly offset by the fact that a proportion of these women would go on to give birth by caesarean section for one or both twins.

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Why the committee made the recommendations

How the recommendations might affect practice

The recommendations are consistent with the NICE guideline on intrapartum care taking into account the twin-specific measures. It is not anticipated that the recommendations will lead to major changes in current clinical practice.

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Why the committee made the recommendations

There is limited evidence on analgesia in labour for women with a twin pregnancy, and no evidence for women with a triplet pregnancy, so the committee used their expertise and experience along with the very limited evidence to make recommendations. They agreed that there is variation in practice in relation to when healthcare professionals discuss analgesia and anaesthesia with women and what they should discuss, so they specified when this should happen during pregnancy and what to cover.

Women with a twin or triplet pregnancy have an increased risk of intervention in labour, including assisted birth or caesarean section for 1 or more of the babies, and additional internal manoeuvres. Having an epidural in place allows analgesia or anaesthesia to be given quickly when it is needed, reducing the potential need for emergency general anaesthesia.

The limited evidence suggested that having an epidural in place also reduces the need for emergency caesarean section for the second twin after vaginal birth of the first twin, possibly by allowing more effective internal manoeuvres to allow the second twin to be born vaginally.

How the recommendations might affect practice

The recommendations reinforce current best practice.

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Why the committee made the recommendations

The evidence was very limited, so the committee used their clinical expertise and experience to make recommendations. Multiple pregnancy is a risk factor for postpartum haemorrhage (see NICE's guideline on intrapartum care) because of over-distension of the uterus and enlarged placenta(s). The committee agreed that healthcare professionals should explain this to women in the antenatal period and assess and re-evaluate each woman's individual risk as her pregnancy progresses.

Because of the risk of postpartum haemorrhage, the committee agreed that active management of the third stage of labour using uterotonics should be offered to all women, and physiological management should not be offered.

It is already well-established as current practice and is supported by the committee's experience that when women have more than 1 risk factor for postpartum haemorrhage, additional uterotonics can reduce this risk. There is no clear evidence on the comparative effectiveness of different uterotonics in twin or triplet pregnancy. Each uterotonic has risk factors and contraindications, so the committee did not recommend a specific one.

The committee agreed on the importance of having existing intravenous access and blood products readily available in case a postpartum haemorrhage does occur.

How the recommendations might affect practice

The recommendations reinforce current best practice.

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