Recommendations

People have the right to be involved in discussions and make informed decisions about their care, as described in your care.

Making decisions using NICE guidance explains how we use words to show the strength (or certainty) of our recommendations, and has information about prescribing medicines (including off-label use), professional guidelines, standards and laws (including on consent and mental capacity), and safeguarding.

Box 1 Chorionicity and amnionicity

Types of twin pregnancy

Dichorionic diamniotic twins

Each baby has a separate placenta and amniotic sac.

Monochorionic diamniotic twins

Both babies share a placenta but have separate amniotic sacs.

Monochorionic monoamniotic twins

Both babies share a placenta and amniotic sac.

Types of triplet pregnancy

Trichorionic triamniotic triplets

Each baby has a separate placenta and amniotic sac.

Dichorionic triamniotic triplets

One baby has a separate placenta and 2 of the babies share a placenta. All 3 babies have separate amniotic sacs.

Dichorionic diamniotic triplets

One baby has a separate placenta and amniotic sac and 2 of the babies share a placenta and amniotic sac.

Monochorionic triamniotic triplets

All 3 babies share 1 placenta but each has its own amniotic sac.

Monochorionic diamniotic triplets

All 3 babies share 1 placenta. One baby has a separate amniotic sac and 2 babies share 1 sac.

Monochorionic monoamniotic triplets

All 3 babies share a placenta and amniotic sac.

1.1 Determining gestational age and chorionicity

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 recommendations 1.1.3 and 1.1.4). For recommendations on chromosomal screening, see recommendations 1.4.3 to 1.4.8. [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 proved 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 (3‑D) 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]

1.2 General care

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 for uncomplicated pregnancies). [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 for uncomplicated pregnancies). Repeat at 28 weeks as in routine antenatal care. [2011]

1.3 Delivery of antenatal and intrapartum care

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 recommendation 1.2.2)

  • the risks, symptoms and signs of preterm labour and the potential need for corticosteroids for fetal lung maturation

  • likely timing of birth (see section 1.9 on timing of birth) and possible modes of birth (see section 1.10 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]

To find out why the committee made the 2019 recommendation on intrapartum care and how it might affect practice, see rationale and impact.

Schedule of specialist antenatal appointments

The schedule of specialist appointments is also shown as part of a multiple pregnancy antenatal care resource produced by the Twins And Multiple Births Association 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 recommendation 1.7.1). [2011]

1.4 Fetal complications

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

Twin pregnancy

1.4.3 Offer women with a twin pregnancy information on and screening for Down's syndrome, Edwards' syndrome and Patau's syndrome as outlined in the NHS fetal anomaly screening programme (FASP). [2019]

Triplet pregnancy

1.4.4 Before offering screening for Down's syndrome, Edwards' syndrome and Patau's syndrome, give women with a triplet pregnancy information about:

  • the greater likelihood of Down's syndrome, Edwards' syndrome and Patau's syndrome in triplet pregnancy

  • the different options for screening

  • the increased false positive rate of screening tests in triplet pregnancy

  • their greater likelihood of being offered invasive testing

  • their greater likelihood of complications of invasive testing

  • the physical risks and psychological implications in the short and long term relating to selective fetal reduction. [2011, amended 2019]

1.4.5 Healthcare professionals who screen for Down's syndrome, Edwards' syndrome and Patau's syndrome in trichorionic triplet pregnancy should:

  • map the fetal positions

  • use nuchal translucency and maternal age to screen for Down's syndrome, Edwards' syndrome and Patau's syndrome when crown–rump length measures from 45.0 mm to 84.0 mm (at approximately 11+2 weeks to 14+1 weeks)

  • calculate the chance of Down's syndrome, Edwards' syndrome and Patau's syndrome for each fetus. [2011, amended 2019]

1.4.6 Refer women with a dichorionic and monochorionic triplet pregnancy who want to have screening for Down's syndrome, Edwards' syndrome and Patau's syndrome to a tertiary level fetal medicine centre. [2019]

1.4.7 Do not use second trimester serum screening for Down's syndrome in triplet pregnancies. [2011, amended 2019]

Referral after screening

1.4.8 Refer women with any type of triplet pregnancy who have a higher chance of Down's syndrome, Edwards' syndrome or Patau's syndrome (use a threshold of 1 in 150 at term) to a fetal medicine specialist in a tertiary-level fetal medicine centre. [2011, amended 2019]

To find out why the committee made the 2019 recommendations on screening for Down's syndrome, Edwards' syndrome and Patau's syndrome and how they might affect practice, see rationale and impact.

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 for uncomplicated pregnancies 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 section 1.5 on preventing preterm birth.

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

  • they have a higher risk of spontaneous preterm birth (see section 1.9 on timing of birth) than women 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. [2019]

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]

To find out why the committee made the 2019 recommendations on screening for preterm birth (and why they did not make a recommendation on cervical length screening) and how they might affect practice, see rationale and impact.

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]

To find out why the committee made this 2019 recommendation and how it might affect practice, see rationale and impact.

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

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
and
(EFW largest fetus − EFW middle fetus) ÷ EFW largest fetus

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]

To find out why the committee made the 2019 recommendations on diagnostic monitoring for fetal growth restriction in dichorionic twin and trichorionic triplet pregnancies, and how they might affect practice, see rationale and impact.

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]

Feto-fetal transfusion syndrome

1.4.25 Offer diagnostic monitoring for feto-fetal transfusion syndrome to women with a monochorionic twin or triplet pregnancy. Monitor with ultrasound every 14 days from 16 weeks until birth. [2019]

1.4.26 Use ultrasound assessment, with a visible amniotic membrane within the measurement image, to monitor for feto-fetal transfusion syndrome. Measure the DVP depths of amniotic fluid on either side of the amniotic membrane. [2019]

1.4.27 Increase the frequency of diagnostic monitoring for feto-fetal transfusion syndrome in the woman's second and third trimester to at least weekly if there are concerns about differences between the babies' amniotic fluid level (a difference in DVP depth of 4 cm or more). Include doppler assessment of the umbilical artery flow for each baby. [2019]

1.4.28 Refer the woman to a tertiary level fetal medicine centre if feto-fetal transfusion syndrome is diagnosed, based on the following:

  • the amniotic sac of 1 baby has a DVP depth of less than 2 cm and

  • the amniotic sac of another baby has a DVP depth of:

    • over 8 cm before 20+0 weeks of pregnancy or

    • over 10 cm from 20+0 weeks. [2019]

1.4.29 Refer the woman to her named specialist obstetrician for multiple pregnancy in her second or third trimester for further assessment and monitoring if:

  • the amniotic sac of 1 baby has a DVP depth in the normal range and

  • the amniotic sac of another baby has a DVP depth of:

    • less than 2 cm or

    • 8 cm or more. [2019]

To find out why the committee made the 2019 recommendations on diagnostic monitoring for complications of monochorionicity, including feto-fetal transfusion syndrome, and how they might affect practice, see rationale and impact.

Fetal growth restriction in monochorionic pregnancy

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

1.4.31 At each ultrasound scan from 16 weeks, offer women with a monochorionic twin or triplet pregnancy diagnostic monitoring for fetal weight discordance using 2 or more biometric parameters (in addition to amniotic fluid level assessment). To assess amniotic fluid levels, measure the DVP on either side of the amniotic membrane. [2019]

1.4.32 Continue monitoring women with a monochorionic twin or triplet pregnancy for fetal weight discordance at intervals that should not exceed 14 days. [2019]

1.4.33 Calculate and document EFW discordance in monochorionic twins using the formula below [2019]:
(EFW larger fetus − EFW smaller fetus) ÷ EFW larger fetus

1.4.34 The named specialist obstetrician should review the estimated fetal weights of dichorionic and monochorionic triplets and calculate EFW discordance based on their understanding of the implications of chorionicity. [2019]

1.4.35 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]

1.4.36 Refer women with a monochorionic twin or 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]

To find out why the committee made the 2019 recommendations on diagnostic monitoring for fetal growth restriction in monochorionic pregnancy and how they might affect practice, see rationale and impact.

Twin anaemia polycythaemia sequence

1.4.37 Offer weekly ultrasound monitoring for TAPS from 16 weeks of pregnancy using middle cerebral artery peak systolic velocity (MCA‑PSV) to women whose pregnancies are complicated by:

  • feto-fetal transfusion syndrome that has been treated by fetoscopic laser therapy or

  • selective fetal growth restriction (defined by an EFW discordance of 25% or more and an EFW of any of the babies below the 10th centile for gestational age). [2019]

1.4.38 For women with a monochorionic pregnancy showing any of the following:

  • cardiovascular compromise (such as fetal hydrops or cardiomegaly) or

  • unexplained isolated polyhydramnios or

  • abnormal umbilical artery

    perform ultrasound MCA‑PSV measurements to help detect advanced-stage TAPS, and seek management advice immediately from a tertiary level fetal medicine specialist. [2019]

To find out why the committee made the 2019 recommendations on diagnostic monitoring for TAPS and how they might affect practice, see rationale and impact.

1.5 Preventing preterm birth

The committee did not make any recommendations on vaginal progesterone for preventing preterm birth in twin pregnancies because of emerging evidence in this area (see rationale and impact). NICE will carry out an exceptional update based on the new evidence when it becomes available.

1.5.1 Do not offer intramuscular progesterone to prevent spontaneous preterm birth in women with a twin or triplet pregnancy. [2019]

1.5.2 Do not offer the following interventions (alone or in combination) routinely to prevent spontaneous preterm birth in women with a twin or triplet pregnancy:

  • arabin pessary

  • bed rest

  • cervical cerclage

  • oral tocolytics. [2019]

To find out why the committee made the 2019 recommendations on preventing preterm birth (and why they did not make a recommendation on vaginal progesterone) and how they might affect practice, see rationale and impact.

Corticosteroids

1.5.3 Inform women with a twin or triplet pregnancy of their increased risk of preterm birth (see recommendation 1.4.13) and about the benefits of targeted corticosteroids. [2011]

1.5.4 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]

1.6 Maternal complications

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 for uncomplicated pregnancies. [2011]

1.6.2 Advise women with a twin or triplet pregnancy to take low-dose aspirin[1] daily from 12 weeks until the birth of the babies if they have 2 or more of the risk factors specified in NICE's guideline on hypertension in pregnancy. [2011, amended 2019]

1.7 Indications for referral to a tertiary level fetal medicine centre

1.7.1 Seek a consultant opinion from a tertiary level fetal medicine centre for:

  • pregnancies with a shared amnion:

    • monochorionic monoamniotic twins

    • dichorionic diamniotic triplets

    • monochorionic diamniotic triplets

    • monochorionic monoamniotic triplets

  • pregnancies complicated by any of the following:

    • fetal weight discordance (of 25% or more) and an EFW of any of the babies below the 10th centile for gestational age

    • fetal anomaly (structural or chromosomal)

    • discordant fetal death

    • feto-fetal transfusion syndrome

    • twin reverse arterial perfusion sequence (TRAP)

    • conjoined twins or triplets

    • suspected TAPS (see recommendations 1.4.37 and 1.4.38). [2011, amended 2019]

1.8 Planning birth: information and support

1.8.1 From 24 weeks in a twin or triplet pregnancy, discuss with the woman (and her family members or carers, as appropriate) her plans and wishes for the birth of her babies. Provide information that is tailored to each woman's pregnancy, taking into account her needs and preferences. Revisit these conversations whenever clinically indicated and whenever the woman wants to. [2019]

1.8.2 Ensure the following has been discussed by 28 weeks at the latest:

  • place of birth and the possible need to transfer in case of preterm birth

  • timing and possible modes of birth

  • analgesia during labour (or for caesarean birth)

  • intrapartum fetal heart monitoring

  • management of the third stage of labour. [2019]

1.8.3 Follow NICE's guideline on patient experience in adult NHS services for how to provide information and communicate with women and their families and carers. [2019]

To find out why the committee made the 2019 recommendations on planning birth and how they might affect practice, see rationale and impact.

1.9 Timing of birth

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]

To find out why the committee made the 2019 recommendations on timing of birth and how they might affect practice, see rationale and impact.

1.10 Mode of birth

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 monoamniotic

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]

To find out why the committee made the 2019 recommendations on mode of birth and how they might affect practice, see rationale and impact.

1.11 Fetal monitoring during labour in twin pregnancy

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 table 10 of NICE's guideline on intrapartum care for healthy women and babies, 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

For definitions of 'suspicious' and 'pathological' cardiotocograph traces, see table 11 of NICE's guideline on intrapartum care for healthy women and babies.

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]

To find out why the committee made the 2019 recommendations on fetal monitoring during labour and how they might affect practice, see rationale and impact.

1.12 Analgesia

1.12.1 Discuss options for analgesia and anaesthesia with women (and their family members or carers, as appropriate), whether they are planning a vaginal birth or caesarean section. Ensure this discussion takes place by 28 weeks at the latest. [2019]

1.12.2 Offer an epidural to women with a twin or triplet pregnancy who choose to have a vaginal birth. Explain that this is likely to:

  • improve the chance of success and optimal timing of assisted vaginal birth of all the babies

  • enable a quicker birth by emergency caesarean section if needed. [2019]

1.12.3 Offer regional anaesthesia to women with a twin or triplet pregnancy who are having a caesarean section. [2019]

To find out why the committee made the 2019 recommendations on analgesia and how they might affect practice, see rationale and impact.

1.13 Managing the third stage of labour

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 for healthy women and babies). [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]

To find out why the committee made the 2019 recommendations on managing the third stage of labour and how they might affect practice, see rationale and impact.

Terms used in this guideline

Active management of the third stage

In a vaginal birth, active management consists of 10 IU of oxytocin by intramuscular injection immediately after the birth of the last baby and before the cord is clamped and cut. In a caesarean section, it consists of 5 IU of oxytocin by intravenous injection immediately after the birth of the last baby and before the cord is clamped and cut.

Amnionicity

The number of amnions (inner membranes) that surround babies in a multiple pregnancy. Pregnancies with 1 amnion (so that all babies share an amniotic sac) are described as monoamniotic; pregnancies with 2 amnions are diamniotic; and pregnancies with 3 amnions are triamniotic. Also see box 1.

Chorionicity

The number of chorionic (outer) membranes that surround babies in a multiple pregnancy. If there is only 1 membrane, the pregnancy is described as monochorionic; if there are 2, the pregnancy is dichorionic; and if there are 3, the pregnancy is trichorionic. Monochorionic twin pregnancies and monochorionic or dichorionic triplet pregnancies carry higher risks because babies share a placenta. Also see box 1.

Feto-fetal transfusion syndrome

Feto-fetal transfusion syndrome (FFTS) occurs when blood moves from one baby to another. The baby that loses the blood is called the donor and the baby receiving the blood is called the recipient. Feto-fetal transfusion syndrome is a complication of monochorionic multiple pregnancies arising from shared placental circulation. It is also referred to as twin-to-twin transfusion syndrome in twin pregnancies.

Group and save

This is a blood sampling process. It consists of a blood group and an antibody screen to determine the woman's blood group and whether she has atypical red cell antibodies in her blood. If atypical antibodies are present, the laboratory will do additional work to identify them. This will allow blood to be issued in an emergency very quickly.

Specialist obstetrician

An obstetrician with a special interest, experience and knowledge of managing multiple pregnancy, and who works regularly with women with a multiple pregnancy.

Tertiary level fetal medicine centre

A specialist regional (or supra-regional) fetal medicine centre that has a multidisciplinary team with the expertise and infrastructure to assess and manage complicated twin and triplet pregnancies. This includes providing complex fetal interventions or therapies, for example, fetoscopic laser ablation for feto-fetal transfusion syndrome; and selective termination of pregnancy using techniques such as fetoscopic cord occlusion or radiofrequency ablation.

Twin anaemia polycythaemia sequences

Twin anaemia polycythaemia sequences (TAPS) is a complication affecting monochorionic twin or triplet pregnancies. It is a rare, chronic form of feto-fetal transfusion caused by the joining of fine blood vessels connecting the fetal circulations on the placenta. It presents when there are unequal blood counts between the twins in the womb. When TAPS occurs, the recipient twin is at risk for successively increasing blood count, called polycythaemia, and the donor twin for progressive blood loss, or anaemia. TAPS occurs without the differences in levels of amniotic fluids between the fetuses (polyhydramnios-oligohydramnios) that is usually seen in FFTS.



[1] At the time of publication (September 2019), aspirin did not have a UK marketing authorisation for this indication. The prescriber should follow relevant professional guidance, taking full responsibility for the decision. Informed consent should be obtained and documented. See the General Medical Council's Prescribing guidance: prescribing unlicensed medicines for further information.

  • National Institute for Health and Care Excellence (NICE)