Perinatal outcomes among singletons after assisted reproductive technology with single-embryo or double-embryo transfer versus no assisted reproductive technology.

Objective: To examine outcomes of singleton pregnancies conceived without assisted reproductive technology (non-ART) compared with singletons conceived with ART by elective single-embryo transfer (eSET), nonelective single-embryo transfer (non-eSET), and double-embryo transfer with the establishment of 1 (DET -1) or ≥2 (DET ≥2) early fetal heartbeats.

Methods: Retrospective cohort using linked ART surveillance data and vital records from Florida, Massachusetts, Michigan, and Connecticut. Methods: Not applicable. Methods: Singleton live-born infants. Methods: None. Methods: Preterm birth (PTB <37 weeks), very preterm birth (VPTB <32 weeks), small for gestational age birth weight (<10th percentile), low birth weight (LBW <2,500 g), very low birth weight (VLBW <1,500 g), 5-minute Apgar score <7, and neonatal intensive care unit (NICU) admission.

Results: After controlling for maternal characteristics and employing a weighted propensity score approach, we found that singletons conceived after eSET were less likely to have a 5-minute Apgar <7 (adjusted odds ratio [aOR] 0.33; 95% CI, 0.15-0.69) compared with non-ART singletons. There were no differences among outcomes between non-ART and non-eSET infants. We found that PTB, VPTB, LBW, and VLBW were more likely among DET -1 and DET ≥2 compared with non-ART infants, with the odds being higher for DET ≥2 (PTB aOR 1.58; 95% CI, 1.09-2.29; VPTB aOR 2.46; 95% CI, 1.20-5.04; LBW aOR 2.17; 95% CI, 1.24-3.79; VLBW aOR 3.67; 95% CI, 1.38-9.77).

Conclusions: Compared with non-ART singletons, singletons born after eSET and non-eSET did not have increased risks whereas DET -1 and DET ≥2 singletons were more likely to have adverse perinatal outcomes.