Caesarean section versus vaginal delivery for preterm birth for women with a single baby (not multiple birth)

There is not enough evidence to show the effects of a policy of planned immediate caesarean delivery rather than a policy of planned vaginal delivery for the birth of premature babies.

Caesarean section is an operation performed to deliver a baby through a cut in the abdomen and womb. Planned caesarean delivery for women thought to be in preterm labour may be protective for the baby, also preventing an intrapartum emergency surgery with its associated complications, but could also be traumatic for both the mother and her baby. More often than not, women thought to be in preterm labour deliver weeks later, often at term. There is, therefore, a real possibility that a policy of planned caesarean section may increase the number of babies born preterm.

We included six randomised studies (involving 122 pregnant women) but only four studies (involving 116 women) contributed to the analyses. Our review found that there is not enough reliable evidence to compare planned caesarean delivery with planned vaginal delivery. Sometimes a planned caesarean cannot happen because labour progresses too quickly and sometimes, even though vaginal delivery is planned, complications arising during labour may make a caesarean section necessary. The review found that not enough women have been recruited into trials and, therefore, the decision how best to deliver a preterm baby, either cephalic or breech presentation, remains opinion and current practice within a hospital, rather than being evidence-based.

All four trials were stopped early, due to difficulties with recruiting women. There were no data on serious maternal complications including admissions to intensive care unit. However, there were seven cases of major maternal postpartum complications in the group allocated to planned caesarean section (wound dehiscence, deep vein thrombosis, endotoxic shock and puerperal sepsis) and none in the group randomised to vaginal delivery. Excess blood loss from the birth canal after childbirth (postpartum haemorrhage) was not clearly different between the two groups, nor was birth asphyxia or respiratory distress syndrome or injury to the baby at birth.

Authors' conclusions: 

There is not enough evidence to evaluate the use of a policy of planned immediate caesarean delivery for preterm babies. Further studies are needed in this area, but recruitment is proving difficult.

Read the full abstract...
Background: 

Planned caesarean delivery for women thought be in preterm labour may be protective for baby, but could also be quite traumatic for both mother and baby. The optimal mode of delivery of preterm babies for both cephalic and breech presentation remains, therefore, controversial.

Objectives: 

To assess the effects of a policy of planned immediate caesarean delivery versus planned vaginal birth for women in preterm labour.

Search strategy: 

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (5 August 2013).

Selection criteria: 

Randomised trials comparing a policy of planned immediate caesarean delivery versus planned vaginal delivery for preterm birth.

Data collection and analysis: 

Two review authors independently assessed trials for inclusion. Two review authors independently extracted data and assessed risk of bias. Data were checked for accuracy.

Main results: 

We included six studies (involving 122 women) but only four studies (involving only 116 women) contributed data to the analyses.

Infant

There were very little data of relevance to the three main (primary) outcomes considered in this review: There was no significant difference between planned immediate caesarean section and planned vaginal delivery with respect to birth injury to infant (risk ratio (RR) 0.56, 95%, confidence interval (CI) 0.05 to 5.62; one trial, 38 women) or birth asphyxia (RR 1.63, 95% CI 0.84 to 3.14; one trial, 12 women). The only cases of birth trauma were a laceration of the buttock in a baby who was delivered by caesarean section and mild bruising in another allocated to the group delivered vaginally.

The difference between the two groups with regard to perinatal deaths was not significant (0.29, 95% CI 0.07 to 1.14; three trials, 89 women) and there were no data specifically relating to neonatal admission to special care and/or intensive care unit.

There was also no difference between the caesarean or vaginal delivery groups in terms of markers of possible birth asphyxia (RR 1.63, 95% CI 0.84 to 3.14; one trial, 12 women) or Apgar score less than seven at five minutes (RR 0.83, 95% CI 0.43 to 1.60; four trials, 115 women) and no difference in attempts at breastfeeding (RR 1.40, 95% 0.11 to 17.45; one trial, 12 women). There was also no difference in neonatal fitting/seizures (RR 0.22, 95% CI 0.01 to 4.32; three trials, 77 women), hypoxic ischaemic encephalopathy (RR 4.00, 95% CI 0.20 to 82.01;one trial, 12 women) or respiratory distress syndrome (RR 0.55, 95% CI 0.27 to 1.10; three trials, 103 women). There were no data reported in the trials specifically relating to meconium aspiration. There was also no significant difference between the two groups for abnormal follow-up in childhood (RR 0.65, 95% CI 0.19 to 2.22; one trial, 38 women) or delivery less than seven days after entry (RR 0.95, 95% CI 0.73 to 1.24; two trials, 51 women).

Mother

There were no data reported on maternal admissions to intensive care. However, there were seven cases of major maternal postpartum complications in the group allocated to planned immediate caesarean section and none in the group randomised to vaginal delivery (RR 7.21, 95% CI 1.37 to 38.08; four trials, 116 women).

There were no data reported in the trials specifically relating to maternal satisfaction (postnatal). There was no significant difference between the two groups with regard to postpartum haemorrhage. A number of non-prespecified secondary outcomes were also considered in the analyses. There was a significant advantage for women in the vaginal delivery group with respect to maternal puerperal pyrexia (RR 2.98, 95% CI 1.18 to 7.53; three trials, 89 women) and other maternal infection (RR 2.63, 95% CI 1.02 to 6.78; three trials, 103 women), but no significant differences in wound infection (RR 1.16, 95% CI 0.18 to 7.70; three trials, 103 women), maternal stay more than 10 days (RR 1.27, 95% CI 0.35 to 4.65; three trials, 78 women) or the need for blood transfusion (results not estimable).