NIHR Signal Caesarean section is better for extremely premature breech babies but not necessarily for their mothers

Published on 5 December 2017

Delivering extremely preterm breech babies (23 to 27 weeks) by caesarean reduced the risk of infant death or brain bleeds by around 40% compared with vaginal delivery.

Choice of delivery is a balance of risks for mother and baby. There are immediate risks to the mother associated with anaesthesia and surgery but also risks in subsequent pregnancies following surgery on the immature uterus. In this review, there was limited information on outcomes for the mothers.

NICE recommend that the mother is informed of the potential harms and benefits of all options. The harms to the mother remain unclear, which is an important gap in knowledge.

Caesarean section is better for extremely premature breech babies but not necessarily for their mothers

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Why was this study needed?

Extremely preterm babies account for 5% of preterm births. In England, in 2006 there were 2,460 extremely preterm births (22 to 26 weeks) where the baby was alive at the start of labour.

Babies born before 22 weeks are unlikely to survive. At 23 weeks babies have 19% chance of survival, rising to 40% at 24 weeks.

A third of extremely preterm babies are in the breech position, rather than head first ready for birth. So across England, this decision whether a breech baby should be delivered vaginally or via caesarean is faced in about 800 births a year.

Delivery can lead to the serious but rare complication of bleeding within the baby’s brain (intraventricular haemorrhage). Caesarean surgery this early in pregnancy may require a vertical incision in the mother’s abdomen (a classical incision) – rather than the low transverse incision used later in pregnancy. This increases risks in future pregnancies and means that future births will usually be by caesarean. The balance of these risks is currently uncertain.

This review compared outcomes for extremely preterm breech babies resuscitated after vaginal or caesarean delivery.

What did this study do?

This systematic review pooled results from 15 studies, including 12,335 extremely preterm (23+0 to 27+6 weeks) breech births where the baby was actively resuscitated. One study was conducted in the UK with most others from other high-income countries. Miscarriages or stillbirths were excluded as these babies are likely to be delivered vaginally, so would have biased results in favour of caesarean.

Most of the studies were observational, with only one small randomised controlled trial. This increases the possibility that complications and other pregnancy factors may have influenced delivery method. However, observational data may be the best available for this “hard to study” group.

There was limited information on longer-term outcomes and fewer births at the earliest gestations. These factors reduce confidence in the findings and may have reduced the size of the benefit.

What did it find?

  • For babies born at 23-27 weeks, delivering via caesarean compared to vaginal birth reduced the risk of death up to six months (corrected age) by 41% (odds ratio [OR] 0.59, 95% confidence interval [CI] 0.36 to 0.95, studies). The benefit was mainly for babies born at 23-24 weeks (OR 0.58, 95% CI 0.45 to 0.75, studies). There was no effect on mortality for babies born at 25-36 weeks or 27 weeks.
  • Caesarean was estimated to lead to 122 fewer deaths per 1,000 births at 23-27 weeks, or eight caesareans needed to prevent one death. At 23-24 weeks it prevented 134 deaths per 1,000, with a needed to treat of seven.
  • For babies born at 23-27 weeks, caesarean reduced the risk of intraventricular haemorrhage by 49% (OR 0.51, 95% CI 0.29 to 0.91, studies), with 12 needing caesarean to prevent one severe bleed. Again, the method had no effect on risk for babies born at 25-26 weeks or 27 weeks.
  • Few maternal outcomes were reported. Two studies reported that vertical incisions were used more often (67% of the time) than low transverse incisions (33%).
  • One study reported that two out of 39 women who had caesareans required a blood transfusion and two were admitted to intensive care, whereas none of the 26 women delivering experienced these outcomes.

What does current guidance say on this issue?

NICE 2015 guidelines recommend that healthcare professionals consider caesarean in women with suspected or confirmed preterm labour from 26 weeks onwards and a breech presentation. There are no specific recommendations relating to extremely preterm labour before 26 weeks of pregnancy. Recommendations emphasise ensuring the woman is aware of the benefits and risks so that she can make an informed decision.

The Royal College of Obstetricians 2017 guidelines do not recommend routine caesarean section for breech presentation in extremely preterm labour (22-25 weeks of pregnancy). Neither is it recommended for later preterm gestations unless there is a risk to maternal or foetal health.

What are the implications?

This review suggests that caesarean delivery may be better for the extremely preterm baby. This is notable considering that babies delivered by caesarean may have been more likely to have complications.

How to deliver a baby who is extremely premature with breech presentation is a complex decision relying on some considerations for mother and baby in the short and long term.

This review highlights the need for more data about extremely preterm birth around the limit of viability. Current guidelines do not recommend caesarean as standard, but women need information to be able to take part in a truly informed decision.

Citation and Funding

Grabovac M, Karim JN, Isayama T, et al. What is the safest mode of birth for extremely preterm breech singleton infants who are actively resuscitated? A systematic review and meta-analyses. BJOG. 2017. [Epub ahead of print].

No funding information was provided for this study.

Bibliography

Marlow N, Bennet C, Draper ES et al. Perinatal outcomes for extremely preterm babies in relation to place of birth in England: the EPICure 2 study. BJOG. 2014;99:f181-88.

NICE. Caesarean section. CG132. London: National Institute for Health and Care Excellence; 2011.

NICE. Preterm labour and birth. NG25. London: National Institute for Health and Care Excellence; 2015.

ONS. Births in England and Wales: 2016. Newport: Office for National Statistics; updated 2016.

Impey LWM, Murphy DJ, Griffiths M, Penna LK on behalf of the Royal College of Obstetricians and Gynaecologists. Management of breech presentation. BJOG. 2017;124:e151-77.

Tommy’s. Premature birth statistics. London: Tommy’s.

Why was this study needed?

Extremely preterm babies account for 5% of preterm births. In England, in 2006 there were 2,460 extremely preterm births (22 to 26 weeks) where the baby was alive at the start of labour.

Babies born before 22 weeks are unlikely to survive. At 23 weeks babies have 19% chance of survival, rising to 40% at 24 weeks.

A third of extremely preterm babies are in the breech position, rather than head first ready for birth. So across England, this decision whether a breech baby should be delivered vaginally or via caesarean is faced in about 800 births a year.

Delivery can lead to the serious but rare complication of bleeding within the baby’s brain (intraventricular haemorrhage). Caesarean surgery this early in pregnancy may require a vertical incision in the mother’s abdomen (a classical incision) – rather than the low transverse incision used later in pregnancy. This increases risks in future pregnancies and means that future births will usually be by caesarean. The balance of these risks is currently uncertain.

This review compared outcomes for extremely preterm breech babies resuscitated after vaginal or caesarean delivery.

What did this study do?

This systematic review pooled results from 15 studies, including 12,335 extremely preterm (23+0 to 27+6 weeks) breech births where the baby was actively resuscitated. One study was conducted in the UK with most others from other high-income countries. Miscarriages or stillbirths were excluded as these babies are likely to be delivered vaginally, so would have biased results in favour of caesarean.

Most of the studies were observational, with only one small randomised controlled trial. This increases the possibility that complications and other pregnancy factors may have influenced delivery method. However, observational data may be the best available for this “hard to study” group.

There was limited information on longer-term outcomes and fewer births at the earliest gestations. These factors reduce confidence in the findings and may have reduced the size of the benefit.

What did it find?

  • For babies born at 23-27 weeks, delivering via caesarean compared to vaginal birth reduced the risk of death up to six months (corrected age) by 41% (odds ratio [OR] 0.59, 95% confidence interval [CI] 0.36 to 0.95, studies). The benefit was mainly for babies born at 23-24 weeks (OR 0.58, 95% CI 0.45 to 0.75, studies). There was no effect on mortality for babies born at 25-36 weeks or 27 weeks.
  • Caesarean was estimated to lead to 122 fewer deaths per 1,000 births at 23-27 weeks, or eight caesareans needed to prevent one death. At 23-24 weeks it prevented 134 deaths per 1,000, with a needed to treat of seven.
  • For babies born at 23-27 weeks, caesarean reduced the risk of intraventricular haemorrhage by 49% (OR 0.51, 95% CI 0.29 to 0.91, studies), with 12 needing caesarean to prevent one severe bleed. Again, the method had no effect on risk for babies born at 25-26 weeks or 27 weeks.
  • Few maternal outcomes were reported. Two studies reported that vertical incisions were used more often (67% of the time) than low transverse incisions (33%).
  • One study reported that two out of 39 women who had caesareans required a blood transfusion and two were admitted to intensive care, whereas none of the 26 women delivering experienced these outcomes.

What does current guidance say on this issue?

NICE 2015 guidelines recommend that healthcare professionals consider caesarean in women with suspected or confirmed preterm labour from 26 weeks onwards and a breech presentation. There are no specific recommendations relating to extremely preterm labour before 26 weeks of pregnancy. Recommendations emphasise ensuring the woman is aware of the benefits and risks so that she can make an informed decision.

The Royal College of Obstetricians 2017 guidelines do not recommend routine caesarean section for breech presentation in extremely preterm labour (22-25 weeks of pregnancy). Neither is it recommended for later preterm gestations unless there is a risk to maternal or foetal health.

What are the implications?

This review suggests that caesarean delivery may be better for the extremely preterm baby. This is notable considering that babies delivered by caesarean may have been more likely to have complications.

How to deliver a baby who is extremely premature with breech presentation is a complex decision relying on some considerations for mother and baby in the short and long term.

This review highlights the need for more data about extremely preterm birth around the limit of viability. Current guidelines do not recommend caesarean as standard, but women need information to be able to take part in a truly informed decision.

Citation and Funding

Grabovac M, Karim JN, Isayama T, et al. What is the safest mode of birth for extremely preterm breech singleton infants who are actively resuscitated? A systematic review and meta-analyses. BJOG. 2017. [Epub ahead of print].

No funding information was provided for this study.

Bibliography

Marlow N, Bennet C, Draper ES et al. Perinatal outcomes for extremely preterm babies in relation to place of birth in England: the EPICure 2 study. BJOG. 2014;99:f181-88.

NICE. Caesarean section. CG132. London: National Institute for Health and Care Excellence; 2011.

NICE. Preterm labour and birth. NG25. London: National Institute for Health and Care Excellence; 2015.

ONS. Births in England and Wales: 2016. Newport: Office for National Statistics; updated 2016.

Impey LWM, Murphy DJ, Griffiths M, Penna LK on behalf of the Royal College of Obstetricians and Gynaecologists. Management of breech presentation. BJOG. 2017;124:e151-77.

Tommy’s. Premature birth statistics. London: Tommy’s.

What is the safest mode of birth for extremely preterm breech singleton infants who are actively resuscitated? A systematic review and meta-analyses

Published on 19 September 2017

Grabovac, M.,Karim, J. N.,Isayama, T.,Korale Liyanage, S.,McDonald, S. D.

Bjog , 2017

BACKGROUND: The safest delivery mode of extremely preterm breech singletons is unknown. OBJECTIVES: To determine safest delivery mode of actively resuscitated extremely preterm breech singletons. SEARCH STRATEGY: We searched Cochrane CENTRAL, MEDLINE, EMBASE, CINAHL and ClinicalTrials. gov from 1994-May 2017. SELECTION CRITERIA: We included studies comparing outcomes by delivery mode in actively resuscitated breech infants between 23+0 -27+6 weeks. DATA COLLECTION AND ANALYSIS: We synthesized data using random effects, generated odds ratios, 95% confidence intervals and number needed to treat (NNT). Our primary outcomes were death (neonatal, before discharge, or by 6 months) and severe intraventricular hemorrhage (grades III/IV), stratified by gestational age (23+0 -24+6 , 25+0 -26+6 , 27+0 -27+6 weeks). MAIN RESULTS: We included 15 studies with 12,335 infants. We found that caesarean was associated with a 41% decrease in odds of death between 23+0 -27+6 weeks (OR 0.59, 95% CI 0.36-0.95, NNT=8), with the greatest decrease at 23+0 -24+6 weeks (OR 0.58, 95% CI 0.44-0.75, NNT=7). The OR at 25+0 -26+6 and, 27+0 -27+6 weeks were 0.72 (0.34-1.52) and 2.04 (0.20-20.62), respectively. We found that caesarean was associated with 49% decrease in odds of severe IVH between 23+0 -27+6 weeks (OR 0.51, 95% CI 0.29-0.91, NNT=12), while the OR at 25+0 -26+6 and 27+0 -27+6 was 0.29 (0.07-1.12) and 0.91 (0.27-3.05), respectively. CONCLUSIONS: Caesarean section was associated with reductions in the odds of death by 41% and of severe IVH by 49% in actively resuscitated breech singletons <28 weeks. The data are mostly observational, which may be inherently biased, and scarce on other morbidities, necessitating thorough discussion between parents and clinicians. This article is protected by copyright. All rights reserved.

Expert commentary

Most UK obstetricians counselling labouring women with an extreme preterm singleton breech advice against caesarean section (CS), because of uncertainty about any protective effect of CS, and concerns about morbidity associated with a classical approach. Also, the nature of extreme preterm labour means that some women apparently in labour will not give birth for several days or weeks.

This publication (admittedly flawed) suggests a protective effect of CS for these babies. Our counselling should now acknowledge that CS is probably in the interests of the baby (if we are sure birth will occur soon), but not of the woman.

Rhona Hughes, Clinical Director for Obstetrics & Neonatology, NHS Lothian