Elective single embryo transfer and perinatal outcomes: a systematic review and meta-analysis

In this meta-analysis, infants conceived after elective single embryo transfer have decreased risks of low birth weight and prematurity than after double embryo transfer but higher risks of prematurity than spontaneous conceptions.

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Rosheen Grady, B.H.Sc., Nika Alavi, M.D., Rachel Vale, B.Sc., Mohammad Khandwala, Sarah D. McDonald, M.D., M.Sc.

Volume 97, Issue 2 , Pages 324-331.e8



To determine whether elective single embryo transfer (eSET) lowers the risk of poor perinatal outcomes associated with IVF, when [1] compared with double embryo transfer (DET) or multiple embryo transfer (MET), and separately, [2] compared with spontaneous conceptions.


Systematic review and meta-analysis.


Centers for reproductive care.


Infertility patients.


MEDLINE, Embase, and bibliographies were searched for the period 1978–2011. Two reviewers independently assessed titles, abstracts, and full studies, extracted data, and assessed quality. Dichotomous data were pooled using relative risks and continuous data with mean differences using a random effects model. Randomized controlled trials (RCTs), case–control studies, and cohort studies that examined any of the primary or secondary outcomes in singleton, twin, or multiple-order infants conceived by eSET as compared with [1] those conceived by DET or MET or [2] spontaneously conceived singleton gestations were included.

Main Outcome Measure(s):

Primary outcomes were preterm birth (PTB,


Sixteen studies were included (eight RCTs, eight cohort studies). Compared with DET-conceived infants, eSET-conceived singletons were less likely to be born either preterm (RCT-based relative risk [RR] 0.37, 95% confidence interval [CI] 0.25–0.55) or with LBW (RCT-based RR 0.25, 95% CI 0.15–0.45; cohort study RR 0.51, 95% CI 0.29–0.91). However, compared with spontaneously conceived singletons, eSET gestations had higher risks of PTB (RR 2.13, 95% CI 1.26–3.61), placenta previa (RR 6.02, 95% CI 2.79–13.01), gestational diabetes (RR 1.69, 95% CI 1.19–2.42), and ectopic pregnancy (RR 6.40, 95% CI 4.38–9.35).


Elective single embryo transfer is associated with decreased risks of PTB and LBW compared with DET but higher risks of PTB compared with spontaneously conceived singletons.

Read the full text at: http://www.fertstert.org/article/S0015-0282(11)02809-3/fulltext

Fertility and Sterility

Editorial Office, American Society for Reproductive Medicine

Fertility and Sterility® is an international journal for obstetricians, gynecologists, reproductive endocrinologists, urologists, basic scientists and others who treat and investigate problems of infertility and human reproductive disorders.