The Association Between Infertility Treatment and Birth Outcomes for Nulliparous Persons Who Gave Birth 35 Years and Older: Findings from 2022 National Vital Statistics System Natality Data.

Objectives: This study uses 2022 National Vital Statistics System natality data to identify characteristics associated with infertility treatment among nulliparous individuals 35 years or older, comparing pregnancy and birth outcomes between no infertility treatment and assisted reproductive technology (ART) or fertility-enhancing drugs or intrauterine insemination (IUI).

Methods: The likelihood of infertility treatment was estimated after controlling for maternal age, education, race and ethnicity, insurance status, Women, Infants and Children (WIC) support, pre-pregnancy body mass index (BMI), chronic hypertension, diabetes, and smoking during pregnancy. Maternal outcomes (gestational diabetes, hypertensive disorders of pregnancy, cesarean birth, maternal morbidity) and neonatal outcomes (preterm birth, low birth weight, neonatal intensive care, and congenital anomalies) were compared for singleton and multifetal births separately.

Results: Among 173,399 births, 13.6% had infertility treatment (10.9% ART, 2.4% IUI). As compared to people who identified as white or Asian, infertility treatment was over one-third less likely for non-Hispanic Black and Hispanic individuals and 2.4 times more likely for those with a graduate degree as compared to those with less than high school. Infertility treatment was associated with significantly higher rates of all adverse maternal and neonatal outcomes, and among multifetal births, ART was associated with a higher rate of maternal morbidity and more frequent gestational diabetes.

Conclusions for practice: Disparities in infertility treatment exist. ART was associated with modest but significantly worse outcomes, particularly for singleton births. Continued monitoring of infertility treatment selection and birth outcomes is needed for informed clinical and public policy decisions.