Obstetric and perinatal outcomes in singleton pregnancies resulting from IVF/ICSI: a systematic review and meta-analysis.

BACKGROUND Earlier reviews have suggested that IVF/ICSI pregnancies are associated with higher risks. However, there have been recent advances in the way IVF/ICSI is done, leading to some controversy as to whether IVF/ICSI singletons are associated with higher perinatal risks. The objective of this systematic review was to provide an up-to-date comparison of obstetric and perinatal outcomes of the singletons born after IVF/ICSI and compare them with those of spontaneous conceptions. METHODS Extensive searches were done by two authors. The protocol was agreed a priori. PRISMA guidance was followed. The data were extracted in 2 × 2 tables. Risk ratio and risk difference were calculated on pooled data using Rev Man 5.1. Quality assessment of studies was performed using Critical Appraisal Skills programme. Sensitivity analysis was performed when the heterogeneity was high (I(2) > 50%). RESULTS There were 20 matched cohort studies and 10 unmatched cohort studies included in this review. IVF/ICSI singleton pregnancies were associated with a higher risk (95% confidence interval) of ante-partum haemorrhage (2.49, 2.30-2.69), congenital anomalies (1.67, 1.33-2.09), hypertensive disorders of pregnancy (1.49, 1.39-1.59), preterm rupture of membranes (1.16, 1.07-1.26), Caesarean section (1.56, 1.51-1.60), low birthweight (1.65, 1.56-1.75), perinatal mortality (1.87, 1.48-2.37), preterm delivery (1.54, 1.47-1.62), gestational diabetes (1.48, 1.33-1.66), induction of labour (1.18, 1.10-1.28) and small for gestational age (1.39, 1.27-1.53). CONCLUSIONS Singletons pregnancies after IVF/ICSI are associated with higher risks of obstetric and perinatal complications when compared with spontaneous conception. Further research is needed to determine which aspect of assisted reproduction technology poses most risk and how this risk can be minimized.