Association between prepregnancy subnormal body weight and obstetrical outcomes after autologous in vitro fertilization cycles: systematic review and meta-analysis

Objective: To study the association between prepregnancy subnormal body weight and obstetrical outcomes after autologous in vitro fertilization (IVF) cycles. Design: Systematic review and meta-analysis. Setting: Not applicable. Patient(s): Women with prepregnancy subnormal body weight (body mass index <18.5 kg/m(2)) and normal body weight (body mass index 18.5-25 kg/m(2)) after assisted reproductive treatment. Interventions(s): None. Main Outcome Measure(s): Clinical pregnancy rate (CPR), live birth rate (LBR), and miscarriage rate. CPR and LBR were calculated at per-woman and per-cycle levels. Result(s): A total of 38 cohort studies with low risk of bias were included. Meta-analyses showed that, compared with normal-weight women, those underweight before pregnancy had a lower CPR at per-woman and per-cycle levels. Compared with normal weight, underweight before pregnancy had little impact on LBR at both per-woman and per-cycle levels, nor on miscarriage rate. Conclusion(s): Compared with women of normal weight, women who were underweight before pregnancy had modest association with a lower CPR, but underweight did not seem to affect LBR or miscarriage after IVF. (C) 2019 by American Society for Reproductive Medicine.