Effects of turning unborn babies from bottom first to head first at the end of pregnancy (around 36 weeks or more) for reducing problems during childbirth

What is the issue?

The best outcomes in childbirth for both mothers and babies are when the baby is born head-first. If the baby is in another position, there is a higher risk of complications including the need for caesarean section. In a ‘breech presentation’ the baby is bottom-down instead of head-down. External cephalic version (ECV) is a technique for turning the unborn baby so it lies head-down. This review looked at the effects of using ECV on babies that were in the breech position at the end of pregnancy (around 36 weeks or more).

Why is this important?

Everyone wants to avoid complications in childbirth and many women want to avoid having a caesarean section. Avoiding the need for surgery is very important in countries with limited resources for healthcare. ECV is sometimes used before the end of pregnancy (around 34 weeks) but the results might be different when it is used just before childbirth. Also, it might not be possible to turn the unborn baby at this late stage. We wanted to know if using ECV at the end of pregnancy resulted in safer childbirth or was harmful.

What evidence did we find?

We found 8 studies involving 1308 women. (We included studies up to 28 February 2015.) All the studies were randomised and involved women with low-risk pregnancies. Using ECV around 36 weeks or more increased the chance that babies were born head-first and reduced the risk of having a caesarean section. There were no clear differences in other outcomes such as the risk of babies dying. The quality of the studies and therefore the strength of the evidence was varied.

What does this mean?

If an unborn baby is lying bottom-down, turning it by ECV just before birth can reduce some of the problems this position can cause. These studies are too small to show if ECV is safe to use in women with low-risk pregnancies, however other types of studies suggest that it is safe. We also do not know if it should be used in high-risk cases, such as mothers who have already had a caesarean section, or who are expecting twins.

A visual summary of some of the results from this review can be found here.

Authors' conclusions: 

Attempting cephalic version at term reduces the chance of non-cephalic presentation at birth, vaginal cephalic birth not achieved and caesarean section. There is not enough evidence from randomised trials to assess complications of ECV at term. Large observational studies suggest that complications are rare.

A visual summary of some of the results from this review can be found here.

Read the full abstract...
Background: 

Management of breech presentation is controversial, particularly in regard to manipulation of the position of the fetus by external cephalic version (ECV). ECV may reduce the number of breech presentations and caesarean sections, but there also have been reports of complications with the procedure.

Objectives: 

The objective of this review was to assess the effects of ECV at or near term on measures of pregnancy outcome. Methods of facilitating ECV, and ECV before term are reviewed separately.

Search strategy: 

We searched the Cochrane Pregnancy and Childbirth Trials Register (28 February 2015) and reference lists of retrieved studies.

Selection criteria: 

Randomised trials of ECV at or near term (with or without tocolysis) compared with no attempt at ECV in women with breech presentation.

Data collection and analysis: 

Two review authors assessed eligibility and trial quality, and extracted the data.

Main results: 

We included eight studies, with a total of 1308 women randomised. The pooled data from these studies show a statistically significant and clinically meaningful reduction in non-cephalic presentation at birth (average risk ratio (RR) 0.42, 95% confidence interval (CI) 0.29 to 0.61, eight trials, 1305 women); vaginal cephalic birth not achieved (average RR 0.46, 95% CI 0.33 to 0.62, seven trials, 1253 women, evidence graded very low); and caesarean section (average RR 0.57, 95% CI 0.40 to 0.82, eight trials, 1305 women, evidence graded very low) when ECV was attempted in comparison to no ECV attempted. There were no significant differences in the incidence of Apgar score ratings below seven at one minute (average RR 0.67, 95% CI 0.32 to 1.37, three trials, 168 infants) or five minutes (RR 0.63, 95% CI 0.29 to 1.36, five trials, 428 infants, evidence graded very low), low umbilical vein pH levels (RR 0.65, 95% CI 0.17 to 2.44, one trial, 52 infants, evidence graded very low), neonatal admission (RR 0.80, 95% CI 0.48 to 1.34, four trials, 368 infants, evidence graded very low), perinatal death (RR 0.39, 95% CI 0.09 to 1.64, eight trials, 1305 infants, evidence graded low), nor time from enrolment to delivery (mean difference -0.25 days, 95% CI -2.81 to 2.31, two trials, 256 women).

All of the trials included in this review had design limitations, and the level of evidence was graded low or very low. No studies attempted to blind the intervention, and the process of random allocation was suboptimal in several studies. Three of the eight trials had serious design limitations, however excluding these studies in a sensitivity analysis for outcomes with substantial heterogeneity did not alter the results.

Share/Save