Differential effect of mode of conception and infertility treatment on fetal growth and prematurity.

Objectives To examine perinatal outcomes in pregnancies conceived by different methods: fertile women with spontaneous pregnancies, infertile women who achieved pregnancy without treatment, pregnancies achieved by ovulation induction (OI) and in vitro fertilization or intra-cytoplasmic sperm injection (IVF/ICSI). Methods Retrospective single-center cohort study including 200 fertile and 748 infertile women stratified according to infertility treatment. The outcome measurements were preterm delivery (PTD), small-for-gestational-age (SGA), gestational diabetes, placenta previa or preeclampsia. Results The overall rate of pregnancy complications was significantly increased in all infertility groups regardless of the infertility treatment (adjusted odds ratio (OR): infertile without treatment 2.3 versus OI 2.2 versus IVF/ICSI 3.4). While PTD was mainly associated to IVF/ICSI (adjusted OR: infertile without treatment 1.3 versus OI 1.6 versus IVF/ICSI 3.3), SGA was significantly associated to both OI and IVF/ICSI (adjusted OR: infertile without treatment 1.9 versus OI 2.7 versus IVF/ICSI 2.6). All these associations remained statistically significant after adjusting by maternal age and twin pregnancy. Conclusions This study confirms the higher prevalence of pregnancy complications in infertile women irrespectively of receiving infertility treatment or not, and further describes a preferential association of prematurity with IVF/ICSI, and SGA with treated infertility (OI and IVF/ICSI).