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Elective birth at 37 weeks' gestation for women with an uncomplicated twin pregnancy.

BACKGROUND
The optimal timing of birth for women with an otherwise uncomplicated twin pregnancy at term is uncertain, with clinical support for both elective delivery at 37 weeks, as well as expectant management (awaiting the spontaneous onset of labour).


OBJECTIVES
To assess a policy of elective delivery from 37 weeks' gestation compared with an expectant approach for women with an otherwise uncomplicated twin pregnancy.


SEARCH METHODS
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (12 December 2013).


SELECTION CRITERIA
Randomised controlled trials with reported data that compared outcomes in mothers and babies who underwent elective delivery from 37 weeks' gestation in a twin pregnancy with outcomes in controls who were managed expectantly.


DATA COLLECTION AND ANALYSIS
At least two review authors independently assessed trial eligibility, trial quality and extracted data from the included trials.


MAIN RESULTS
Two randomised controlled trials comparing elective birth at 37 weeks for women with an uncomplicated twin pregnancy, with expectant management were included, involving 271 women and 542 infants. One trial was at an overall low risk of bias, and one trial was at unclear risk of selection bias, performance bias and detection bias.There were no statistically significant differences identified between a policy of elective birth at 37 weeks' gestation and expectant management with regards to birth by caesarean section (two studies; 271 participants; risk ratio (RR) 1.05; 95% confidence interval (CI) 0.83 to 1.32); perinatal death or serious perinatal morbidity (two studies; 542 infants; RR 0.34; 95% CI 0.01 to 8.35); or maternal death or serious maternal morbidity (one study; 235 women; RR 0.29; 95% CI 0.06 to 1.38).There were no statistically significant differences identified for the pre-specified secondary maternal and infant review outcomes reported by these two trials between the two treatment policies (including for: haemorrhage requiring blood transfusion; instrumental vaginal birth; meconium-stained liquor; Apgar score less than seven at five minutes; admission to neonatal intensive care; birthweight less than 2500 g; neonatal encephalopathy; and respiratory distress syndrome). While not a pre-specified review outcome, elective birth at 37 weeks, compared with expectant management, was shown to significantly reduce the risk of infants being born with a birthweight less than the third centile (one study; 470 infants; RR 0.30; 95% CI 0.13 to 0.68).


AUTHORS' CONCLUSIONS
Early birth at 37 weeks' gestation compared with ongoing expectant management for women with an uncomplicated twin pregnancy does not appear to be associated with an increased risk of harms, findings which are consistent with the United Kingdom's National Institute for Health and Care Excellence (NICE) recommendations which advocate birth for women with a dichorionic twin pregnancy at 37 + 0 weeks' gestation. It is unlikely that sufficient clinical equipoise exists to allow for the randomisation of women to a later gestational age at birth.