Perinatal risk in singleton pregnancies after in vitro fertilization.

OBJECTIVE: To assess perinatal risks to singleton births after in vitro fertilization (IVF) versus spontaneous conception.

DESIGN: Cross-sectional.

SETTING: A 2006 registry database of the Japan Society of Obstetrics and Gynaecology (JSOG) capturing 5.8% of total births.

PATIENT(S): 53,939 singleton births from spontaneous conceptions and 1,408 singletons after IVF.

INTERVENTION(S): None.

MAIN OUTCOME MEASURE(S): Perinatal death, low-birth weight (LBW), small for gestational age (SGA), congenital malformation, and sex ratio assessment based on singleton birth cases versus singleton live-born cases.

RESULT(S): In this study, IVF may include intracytoplasmic sperm injection (ICSI), gamete intrafallopian transfer, or IVF followed by zygote intrafallopian transfer. In crude and adjusted analysis, perinatal death, SGA, congenital malformation, and sex ratio were not statistically significantly associated with IVF. The LBW rates were statistically significantly higher in IVF pregnancies, but the association statistically significantly decreased after adjusting for confounding factors. Placental previa, a maternal outcome, was found to be statistically significantly higher in IVF pregnancies.

CONCLUSION(S): No evidence was implicated IVF procedures as dramatically increasing the adjusted risk of perinatal death, LBW, SGA, congenital malformation, or sex ratio when compared with spontaneous conceptions. However, because of sample size limitations, the study cannot exclude small to moderate increases in perinatal deaths or congenital malformations.