Guidance
Rationale and impact
- Intrapartum care
- Screening for chromosomal conditions
- Screening for preterm birth
- Screening for fetal growth restriction and feto-fetal transfusion syndrome in the first trimester
- Diagnostic monitoring for fetal growth restriction in dichorionic twin and trichorionic triplet pregnancies
- Diagnostic monitoring for feto-fetal transfusion syndrome
- Diagnostic monitoring for fetal growth restriction in monochorionic twin and triplet pregnancy
- Diagnostic monitoring for twin anaemia polycythaemia sequence
- Preventing preterm birth
- Planning birth: information and support
- Timing of birth
- Mode of birth
- Fetal monitoring during labour in twin pregnancy
- Analgesia
- Managing the third stage of labour
Rationale and impact
These sections briefly explain why the committee made the recommendations and how they might affect practice. They link to details of the evidence and a full description of the committee's discussion.
Intrapartum care
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.
Screening for chromosomal conditions
Recommendations 1.4.3 to 1.4.8
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.
Screening for preterm birth
Recommendations 1.4.13 to 1.4.15
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.
Screening for fetal growth restriction and feto-fetal transfusion syndrome in the first trimester
Why the committee made the recommendation
Fetal growth restriction
There was evidence that discordance in either crown–rump length or nuchal translucency during the first trimester is not an accurate predictor of growth discordance in the second and third trimester. The committee discussed the evidence for other ultrasound screening measures in the first trimester and decided that because of its low quality they were not confident in recommending any screening tests in the first trimester.
Feto-fetal transfusion syndrome
The evidence showed that none of the first trimester screening tests were able to detect the risk of feto-fetal transfusion syndrome developing later in the pregnancy. Although there were uncertainties in this evidence, it was supported by the committee's clinical experience and current clinical practice.
How the recommendation might affect practice
The recommendation reinforces current practice.
Diagnostic monitoring for fetal growth restriction in dichorionic twin and trichorionic triplet pregnancies
Recommendations 1.4.17 to 1.4.23
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.
Frequency of ultrasound scanning
The evidence was limited on the frequency of ultrasound scanning for women with dichorionic twin pregnancies but, based on their expertise, the committee agreed that women with a dichorionic twin pregnancy should have scans no more than 28 days apart.
They also recommended ultrasound monitoring at least every 14 days for women with all types of triplet pregnancy (recommendations 1.4.19 and 1.4.32) because they are at higher risk of fetal growth restriction.
Fetal weight discordance and estimated fetal weight below 10th centile for gestational age: diagnostic monitoring and referral
Based on both the evidence and their expertise, the committee recommended using at least 2 different biometric parameters as well as amniotic fluid level assessment to provide greater accuracy in calculating estimated fetal weight (EFW).
The Royal College of Obstetricians and Gynaecologists' Green Top guideline on monochorionic twin pregnancy recommends referring women 'for assessment and management in fetal medicine units with recognised relevant expertise' if there is an EFW discordance of more than 20%. In the committee's experience, this level of discordance should cause concern in all types of twin and triplet pregnancy and should prompt increased monitoring. However, they recommended instead increasing to weekly monitoring and adding the extra parameter of a Doppler assessment. This would be equivalent to the specialist assessment recommended by the Green Top guideline because it would need to be carried out by the specialist core team (in line with recommendation 1.3.1) who have experience and knowledge of managing twin and triplet pregnancies. The committee agreed that this would not be inconsistent with the Green Top guideline.
The committee also agreed that the EFWs themselves should be taken into account. Based on the evidence and their expertise they recommended the 10th centile for gestational age as a threshold for concern that should prompt increased monitoring.
The evidence was inconclusive about an exact threshold for referral to a tertiary level fetal medicine centre, so based on their own experience the committee decided that an EFW discordance of 25% or more (along with an EFW below the 10th centile for gestational age) should warrant referral. At this level of discordance, there would be an increased risk of perinatal morbidity and mortality that should prompt intervention rather than increased assessment. The tertiary level fetal medicine centre would have the expertise to weigh up the benefits and risks of conservative management, birth or invasive fetal therapy to improve the chance of a positive pregnancy outcome.
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.
Diagnostic monitoring for feto-fetal transfusion syndrome
Recommendations 1.4.24 to 1.4.29
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.
Diagnostic monitoring for fetal growth restriction in monochorionic twin and triplet pregnancy
Recommendations 1.4.30 to 1.4.36
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.
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.
Frequency of ultrasound scanning
The evidence was limited on the frequency of ultrasound scanning for women with monochorionic pregnancies, so the committee used their expertise to make recommendations. They agreed that women with a monochorionic twin pregnancy need more frequent scans than women with a dichorionic twin pregnancy because they have a higher risk of severe growth discordance.
Scanning at no more than 14-day intervals would allow the woman to be referred promptly either to her specialist obstetrician for multiple pregnancy or to a tertiary level fetal medicine centre depending on the EFWs (see below). The committee also agreed that because women with a monochorionic pregnancy should be having scans at 14‑day intervals to monitor for feto-fetal transfusion syndrome, these timings mean they can be monitored for both of these complications at the same time (in line with recommendation 1.4.24).
The committee also recommended ultrasound monitoring at least every 14 days for women with all types of triplet pregnancy (recommendations 1.4.19 and 1.4.32) because they are at higher risk of fetal growth restriction.
Fetal weight discordance and estimated fetal weight below 10th centile for gestational age: diagnostic monitoring and referral
Based on both the evidence and their expertise, the committee recommended using at least 2 different biometric parameters as well as amniotic fluid level assessment to provide greater accuracy in calculating EFW.
The Royal College of Obstetricians and Gynaecologists' Green Top guideline on monochorionic twin pregnancy recommends referring women 'for assessment and management in fetal medicine units with recognised relevant expertise' if there is an EFW discordance of more than 20%. The committee agreed with the Green Top guideline that this level should cause concern and prompt increased monitoring, but they recommended instead increasing to weekly monitoring and adding the extra parameter of a Doppler assessment. This would be equivalent to the specialist assessment recommended by the Green Top guideline because it would need to be carried out by the specialist core team (in line with recommendation 1.3.1) who have experience and knowledge of managing twin and triplet pregnancies. The committee agreed that this would not be inconsistent with the Green Top guideline.
The committee also agreed that the estimated fetal weights themselves should be taken into account. Based on the evidence they recommended the 10th centile for gestational age as a threshold for concern that should prompt increased monitoring.
The evidence was inconclusive about an exact threshold for referral to a tertiary level fetal medicine centre, so based on their own experience the committee decided that an EFW discordance of 25% or more (along with an EFW below the 10th centile) should warrant referral. At this level of discordance, there would be an increased risk of perinatal morbidity and mortality that should prompt intervention rather than increased assessment. The tertiary level fetal medicine centre would have the expertise to weigh up the benefits and risks of conservative management, birth or invasive fetal therapy to try to improve the chance of a positive pregnancy outcome.
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.
Diagnostic monitoring for twin anaemia polycythaemia sequence
Recommendations 1.4.37 and 1.4.38
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:
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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.
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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 pre-viable 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.
Preventing preterm birth
Recommendations 1.5.1 to 1.5.6
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.
Planning birth: information and support
Recommendations 1.8.1 to 1.8.3
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.
Timing of birth
Recommendations 1.9.1 to 1.9.12
Why the committee made the recommendations
Antenatal information for women
The committee agreed that it was critical to give women the information they need to participate in shared decisions about when their babies are born. This includes explaining the known risk of spontaneous preterm birth in twin and triplet pregnancy and its possible consequences, such as admission to a neonatal unit. The committee retained this advice from the 2011 guideline because it was consistent with their experience and knowledge. They agreed that this information is important for planning the timing of birth.
Women also need to know why it is recommended for them to have a planned birth by a particular week of pregnancy (also see when to offer planned birth). There is a trade-off between clinical benefits and harms when women have not given birth spontaneously by a given gestational age. These include the risks of neonatal mortality and morbidity associated with planned birth compared with the risks of stillbirth from continued pregnancy. The committee agreed that both timing and mode of birth should be discussed with women in the context of these potential risks. Women can use this advice to make an informed choice.
When to offer planned birth
There was not enough good evidence to conclusively identify the optimal timing of birth according to chorionicity and amnionicity, so the committee also used their expertise and experience to make recommendations.
Twin pregnancy
Evidence suggests a consistently higher fetal death rate (at all gestational ages) in monochorionic twin pregnancies than in dichorionic twin pregnancies. The committee therefore recommended earlier planned birth, at 36 weeks, for women with a monochorionic diamniotic pregnancy to reflect the higher risk and complexity of this type of pregnancy. This was consistent with the 2011 guideline and therefore corresponds to current clinical practice.
The committee also clarified the timing of birth for monochorionic monoamniotic twins, which was not explicitly covered by the 2011 guideline – the previous guideline did not divide monochorionic twins into diamniotic or monoamniotic groups. Based on some evidence and their own knowledge and experience, the committee recommended offering planned birth between 32+0 and 33+6 weeks because this timing did not appear to be associated with an increased risk of serious neonatal adverse outcomes.
Uncomplicated trichorionic triamniotic or dichorionic triamniotic triplet pregnancy
The committee clarified the recommendations from the 2011 guideline by considering triplet pregnancies by type rather than as a single group. No evidence was found on timing of birth in triplet pregnancy but the committee agreed based on their own clinical experience that continuing an uncomplicated trichorionic triamniotic or a dichorionic triamniotic triplet pregnancy beyond 35+6 weeks of pregnancy would lead to an increased risk of fetal death (recommendation 1.9.7). Planned birth should therefore be offered at 35 weeks (recommendation 1.9.10).
Individual assessment to determine timing of birth
Because of significant risks for the babies in complicated twin and triplet pregnancies, and the rareness of monochorionic triamniotic triplet pregnancies and triplet pregnancies with a shared amnion, timing of birth should be assessed and discussed individually (recommendations 1.9.8 and 1.9.11).
When planned birth is declined
The committee highlighted that women's choice needs to be respected and that if a woman declines planned birth at the recommended time, she should be offered weekly appointments to minimise risk, monitor progress and help to identify any complications as soon as possible.
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.
Mode of birth
Recommendations 1.10.1 to 1.10.7
Why the committee made the recommendations
Twin pregnancy: dichorionic diamniotic and monochorionic diamniotic
For women who are more than 32 weeks pregnant and have an uncomplicated pregnancy, the evidence showed there is no significant difference in risk between vaginal birth and caesarean section, both for the woman and her babies. The committee's experience supported this, so they agreed that healthcare professionals should explain this to the woman and support her choice as long as the conditions in recommendation 1.10.1 are met and the first baby is in a head-first position.
There was only limited evidence about mode of birth when the first baby is not head first. The committee agreed that in their clinical experience, this carries a higher risk of problems such as cord accidents during birth. Because of this, a caesarean section is the safest option to offer women after 32 weeks and for women in established preterm labour between 26 and 32 weeks.
According to the evidence, not all women give birth according to their birth plan. The committee decided it was important to explain this to women so that they are prepared for the possibility of not giving birth in the way they prefer.
Monochorionic monoamniotic twin pregnancy and triplet pregnancy
Monochorionic monoamniotic twin pregnancies and triplet pregnancies are the least common and highest-risk types of pregnancy and evidence about mode of birth was limited for these women. However, the committee agreed from their experience that caesarean section should be the preferred option and should be offered at the time the birth is planned to happen or after the diagnosis of established labour. If the first twin is close to being born vaginally there can be risks for the babies, so the committee decided that senior obstetric assessment would be needed.
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.
Fetal monitoring during labour in twin pregnancy
Recommendations 1.11.1 to 1.11.21
Why the committee made the recommendations
Twin pregnancy
There was no evidence on the most effective method of fetal monitoring in labour for improving outcomes in women with a twin pregnancy and their babies, so the committee used their expertise and experience along with NICE guidance on fetal monitoring in singleton pregnancy (NICE's guideline on intrapartum care) to make recommendations. They agreed that clinically it is well recognised that twins are at increased risk of complications during labour, especially the second twin, so they recommended continuous fetal monitoring. Continuous cardiotocography monitoring is the only modality that can assess both twin fetal heart rates simultaneously during established labour.
Antenatal information for women
The committee agreed on the importance of explaining to women the lack of evidence about monitoring with cardiotocography specifically in twins, and that recommendations are based on NICE guidance for singleton pregnancy (intrapartum care). Healthcare professionals should provide a detailed explanation of what cardiotocography involves and why it is used and give women a chance to discuss their wishes and concerns. Recommending this before 28 weeks gives women time to make an informed decision and takes into account the fact that many twins are born prematurely.
Intrapartum monitoring
The committee recommended offering continuous cardiotocography to women in established labour with a twin pregnancy over 26 weeks because at this gestational age, neonatal survival rates improve and the risks of neonatal morbidity from preterm birth are falling. The advantages of using cardiotocography over intermittent auscultation monitoring include the ability to assess baseline variability and monitor continuously.
Performing a portable ultrasound (bedside) scan at the start of established labour not only helps to confirm which is the first and which the second twin and locate the fetal hearts but also confirms presentation – malpresentation is more common in twin pregnancy than singleton pregnancy and an emergency caesarean section may be indicated if the first twin presents in the breech position.
The committee recommended involving a senior obstetrician to decide how twins are monitored in established extreme premature labour (23+0 to 25+6 weeks of pregnancy) in line with NICE's guideline on premature labour and birth in singleton pregnancies.
The committee recommended dual channel monitors to make sure both fetal heart rates could be monitored and displayed accurately at the same time on the same record during labour. Maternal pulse monitoring should be displayed on the same continuous cardiotocography trace to ensure 2 fetal heart rates were being recorded (without mistaking the maternal heart rate for a fetal heart rate).
The committee recommended classifying and interpreting cardiotocography in a way that is broadly consistent with the NICE guideline on intrapartum care, but with additional considerations specific to twins. These include regarding twin pregnancy as a fetal clinical risk factor when classifying a cardiotocograph finding as 'abnormal' or 'non-reassuring'. This would result in a lower threshold for classifying a cardiotocograph as pathological.
Management based on cardiotocography
Failing to successfully monitor one or both babies could lead to adverse perinatal outcomes so the committee recommended involving a senior healthcare professional. They also recommended applying a fetal scalp electrode to the first baby while continuing abdominal monitoring of the second baby if abdominal monitoring is unsuccessful or there are concerns about synchronicity of the fetal hearts. This should only be carried out after 34 weeks of pregnancy and if there are no contraindications such as HIV, hepatitis or maternal thrombocytopenia.
If there is 'suspicious' cardiotocography in the first baby during established labour, the committee recommended involving a senior healthcare professional to help manage reversible causes such as dehydration, infection or positional loss of contact, before applying a fetal scalp electrode to the first baby (in the absence of contraindications) while continuing abdominal monitoring of the second baby.
In case of 'pathological' cardiotocography in the first baby, a senior healthcare professional should discuss with the woman using fetal blood sampling in the first baby if the benefits are likely to outweigh the potential risks – these include avoiding a second-stage caesarean section, which increases maternal morbidity and mortality.
After the first baby is born, cardiotocographic monitoring of the second baby should continue to detect any 'suspicious' or 'pathological' cardiotocography that could lead to the need for a caesarean section.
Triplet pregnancy
The committee did not make recommendations for women with a triplet pregnancy because most of these women give birth by caesarean section. Monitoring in labour would therefore be rare and decisions would be made on an individual basis.
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.
Analgesia
Recommendations 1.12.1 to 1.12.3
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.
Managing the third stage of labour
Recommendations 1.13.1 to 1.13.9
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.