Preterm birth and low birth weight among in vitro fertilization singletons: A systematic review and meta-analyses

McDonald, Sarah D.; Han, Zhen; Mulla, Sohail; Murphy, Kellie E.; Beyene, Joseph; Ohlsson, Arne; on behalf of the Knowledge Synthesis Group,

doi:10.1016/j.ejogrb.2009.05.035

« Previous Next »European Journal of Obstetrics & Gynecology and Reproductive Biology
Volume 146, Issue 2 , Pages 138-148, October 2009

Preterm birth and low birth weight among in vitro fertilization singletons: A systematic review and meta-analyses

Sarah D. McDonald
- Division of Maternal-Fetal Medicine, Departments of Obstetrics & Gynecology, and Diagnostic Imaging, McMaster University, Hamilton, Canada
- Corresponding author at: McMaster University, Division of Maternal-Fetal Medicine, Departments of Obstetrics & Gynecology and Diagnostic Imaging and Clinical Epidemiology & Biostatistics, 1200 Main St. West, HSC 3N52B, Hamilton, Ontario L8N 3Z5, Canada. Tel.: +1 905 525 9140x26622; fax: +1 905 524 2911.
Zhen Han
- Department of Obstetrics and Gynecology, First Affiliated Hospital of Xi’an Jiao Tong University, Shaanxi Province, PR China
Sohail Mulla
- Faculty of Health Sciences, McMaster University, Hamilton, Canada
Kellie E. Murphy
- Department of Obstetrics and Gynecology, Mount Sinai Hospital, Toronto, Ontario, Canada
- Department of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada
Joseph Beyene
- Department of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada
- Child Health Evaluative Sciences, The Hospital for Sick Children, Toronto, Ontario, Canada
Arne Ohlsson
- Department of Obstetrics and Gynecology, Mount Sinai Hospital, Toronto, Ontario, Canada
- Department of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada
- Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada
on behalf of the Knowledge Synthesis Group
- See Appendix C.

Received 12 January 2009; received in revised form 21 April 2009; accepted 25 May 2009. published online 29 June 2009.

Abstract

Our objective was to determine the risks of preterm birth (PTB) and low birth weight (LBW) in singletons conceived through in vitro fertilization (IVF)±intracytoplasmic sperm injection (ICSI) compared to spontaneously conceived singletons after matching or controlling for at least maternal age. The MOOSE guidelines for meta-analysis of observational studies were followed. Medline and Embase were searched using comprehensive search strategies. Bibliographies of identified articles were reviewed. English language studies examining LBW or PTB in singletons conceived by IVF or IVF/intracytoplasmic sperm injection, compared with spontaneously conceived singletons, that matched or controlled for at least maternal age. Two reviewers independently assessed titles, abstracts, full articles and study quality and extracted data. Dichotomous data were meta-analyzed using relative risks (RR) as measures of effect size with a random effects model and for continuous data weighted mean difference was calculated. Seventeen studies were included with 31,032 singletons conceived through IVF (±ICSI) and 81,119 spontaneously conceived singletons. After matching or controlling for maternal age and often other factors, compared to spontaneously conceived singletons, IVF singletons had increased risks of our two primary outcomes, PTB (RR 1.84, 95% CI 1.54, 2.21) and LBW (<2500g, RR 1.60, 95% CI 1.29, 1.98). Singletons conceived through IVF or IVF/ICSI were at increased risk for late PTB (32–36 weeks, RR 1.52, 95% CI 1.01, 2.30), moderate PTB <32–33 weeks (RR 2.27, 95% CI 1.73, 2.97), very LBW (<1500g, RR 2.65, 95% CI 1.83, 3.84), and intrauterine growth restriction (RR 1.45, 95% CI 1.04, 2.00), lower birth weights (−97g, 95% CI −161g, −33g) and shorter mean gestations (−0.6 weeks, 95% CI −0.9 weeks, −0.4 weeks). In conclusion, IVF singletons have significantly increased risks of PTB, LBW and other adverse perinatal outcomes compared to spontaneously conceived singletons after matching or controlling for maternal age at least.