Reproductive Outcomes in Women Born With Low Birth Weight, Preterm or Small for Gestational Age: A Population-Based Register Study.

Abstract

To evaluate if the reduced likelihood of reproducing among women born small for gestational age (SGA), preterm (PT) or with low birth weight (LBW) persists towards the end of their reproductive era and to evaluate their use of medically assisted reproduction (MAR). Population-based register study. Sweden. Women born in Sweden between 1973 and 1993 (n = 1 000 148). Data was retrieved from registers, among others the Swedish Medical Birth Register. The study population was stratified into two cohorts, born 1973 to 1983 and 1984 to 1993. The likelihood of giving birth was analysed using a Cox Proportional Hazards model. Giving birth to at least one child. Women born SGA, PT or LBW had a lower probability of giving birth (presented as HR), adjusted for sociodemographic factors, with 95% CI: SGA: HR 0.94 (0.93-0.96); PT: HR 0.95 (0.94-0.96); and LBW: HR 0.90 (0.88-0.92) but no reduction was seen for women in the younger cohort born SGA (HR 0.98 [0.95-1.01]). Women born SGA or LBW had a lower chance of childbirth after MAR (SGA 80.3%, LBW 80.0%) compared to women born with normal weight (84.6%, p < 0.001) as well as an increased risk of being treated with oocyte donation (SGA 5.5% vs. 2.5%, p < 0.001; LBW 5.0% vs. 2.5%, p < 0.001). The decreased probability of parenthood for women born LBW, SGA, or preterm was even more evident after a longer follow-up time. When pursuing MAR with their own oocytes, they had a lower chance of conceiving.