Birth Outcomes by Infertility Treatment: Analyses of the Population-Based Cohort: Massachusetts Outcomes Study of Assisted Reproductive Technologies (MOSART).

Objective: To evaluate pregnancy and birth outcomes by type of infertility treatment received.

Study Design: Assisted reproductive technology (ART) data on women who were both treated and gave birth in Massachusetts were linked to vital records and hospital data. Singleton and twin live births were categorized by ART treatment parameters. Risks for adverse outcomes (pregnancy-induced hypertension [PIH], gestational diabetes [GDM, primary cesarean [CS], prematurity [PTB], low birthweight [LBW], small for gestational age [SGA], large for gestational age [LGA], and birth defects [BD]) were modeled using logistic regression (adjusted odds ratios and 95% confidence intervals), adjusted for parental and treatment factors. GDM and PIH were additionally modeled as adverse outcomes.

Results: Among the 8,948 pregnancies, risks were significantly higher among twins (PIH 2.58, GDM 1.30, CS 5.83, PTB 11.84, LBW 10.68, SGA 2.17, BD 2.54), donor oocytes (PIH 1.87, CS 1.43, PTB 1.43), ICSI (SGA 1.20), and the presence of > 1 fetal heartbeat at 6 weeks' gestation (2 fetal heartbeats: PTB 1.49, LBW 1.57; 3 fetal heartbeats: PTB 2.07, LBW 2.30, SGA 2.04). Thawed embryos were associated with a higher risk for PIH (1.30) but lower risks for LBW (0.79) and SGA (0.38). GDM was associated with increased risks for CS (1.22), LGA (1.40), and BD (1.50); PIH was associated with risks for CS (1.86), PTB (2.70), and LBW (1.83).

Conclusion: Plurality is the predominant ART treatment risk factor associated with substantial excess morbidity for both mother and infants.