Preterm delivery and low birth weight in singleton pregnancies conceived by women with and without a history of infertility

Abstract

Objective To determine predictors of low birth weight (LBW) and preterm delivery (PTD) in singleton pregnancies conceived by women with and without a history of infertility. Design Retrospective cohort study. Setting Eleven infertility clinics in Northern California. Patients Three groups of women who carried singleton pregnancies to ≥ 20 weeks gestation: 542 infertile women who conceived after treatment, 441 infertile women who conceived spontaneously, and 1008 fertile women for comparison. Interventions Chart review. Main Outcome Measures Association of LBW or PTD with infertility treatment, maternal age, parity, obesity, or development of gestational diabetes. Results Infertile women who conceived with treatment were more likely to be obese, develop gestational diabetes, and have ovarian, ovulatory, or male factor infertility than infertile women who conceived spontaneously. Infertile women who conceived after treatment had 1.61 (95% CI 1.08– 2.41) times greater odds of having a LBW infant. Nulliparity was an independent predictor of LBW 1.54 (95% CI 1.09– 2.16) and PTD (OR 1.72, 95% CI 1.20–2.49) in all three groups after controlling for maternal age, history of infertility, infertility treatment, obesity, and gestational diabetes. Conclusions Nulliparous women and women with a history of infertility who conceive a singleton after treatment may be at increased odds for having a LBW infant. Infertile women do not appear to be at increased odds for PTD.

Low birth weight: is it related to assisted reproductive technology or underlying infertility?

“…Recent meta-analyses have revealed a higher rate of LBW in IVF singletons and twins, respectively, compared to natural conceptions (12, 13). Although some data suggests that singleton infants are also at increased risk of LBW, even at term (3, 4, 14–19), other investigators have not observed such differences (20–23). For instance, Isaksson et al reported that the incidence of LBW in IVF singletons was comparable to unassisted conceptions (24).…”

Perinatal and Childhood Outcomes Associated with Infertility

“…One retrospective study of 11 infertility clinics in northern California compared three groups: infertile women who conceived after treatment (not limited to IVF), infertile women who conceived spontaneously, and fertile women. 7 Infertile women who conceived after treatment were at an increased odds of having a LBW infant, whereas infertile women who conceived spontaneously were comparable to fertile women. This study suggests that the fertility treatment is independently associated with LBW.…”

“…This study suggests that the fertility treatment is independently associated with LBW. 7 More recently, attention has turned to the supraphysiologic estradiol levels resulting from ovarian stimulation during IVF as an etiology for adverse perinatal outcomes. Supraphysiologic estradiol levels can affect the peri-implantation maternal environment and possibly placental cell migration and invasion.…”

Evidence-based reproductive risk epidemiology: the importance of multidisciplinary and multiprofessional methodologic collaboration

“…Camarano et al (2) was a retrospective analysis nested within an existing large and validated Californian cohort of infertile women with external controls, although it would have been ideal to perform the entire study within the same cohort (4,5). More specifically, the investigators have reassured the editors-and, we hope, the readers-in regard to the issues of recall bias, the play of chance, and confounding; they used mediation analysis for further clarification and complied with the requirements of the Strobe Initiative on Observational Studies.…”

“…The publication process for the manuscript submitted by Camarano et al (2) would be an example of the latter option. To the extent that up to 75% of perinatal mortality or morbidity is due to or associated with prematurity or low birth weight (LBW), their manuscript addressed a question of immense public health and reproductive importance.…”