# The effect of fertility treatment and socioeconomic status on neonatal and post-neonatal mortality in the United States

## TL;DR

Fertility treatments are linked to higher neonatal and lower post-neonatal infant mortality, with effects varying by socioeconomic status.

## Contribution

This study identifies how fertility treatment and socioeconomic status jointly influence neonatal and post-neonatal mortality rates in the U.S.

## Key findings

- Fertility treatment is associated with higher neonatal mortality, especially among low socioeconomic status families.
- Fertility treatment is linked to lower post-neonatal mortality, particularly in low socioeconomic status families.
- Socioeconomic status significantly modifies the effect of fertility treatment on infant mortality outcomes.

## Abstract

To determine the association between fertility treatment, socioeconomic status (SES), and neonatal and post-neonatal mortality.

Retrospective cohort study of all births (19,350,344) and infant deaths from 2014–2018 in the United States. The exposure was mode of conception—spontaneous vs fertility treatment. The outcome was neonatal (<28d), and post-neonatal (28d–1y) mortality. Multivariable logistic models were stratified by SES.

The fertility treatment group had statistically significantly higher odds of neonatal mortality (high SES OR 1.59; CI [1.5, 1.68], low SES OR 2.11; CI [1.79, 2.48]) and lower odds of post-neonatal mortality (high SES OR 0.87, CI [0.76, 0.996], low SES OR 0.6, CI [0.38, 0.95]). SES significantly modified the effect of ART/NIFT on neonatal and post-neonatal mortality.

Fertility treatment is associated with higher neonatal and lower post-neonatal mortality and SES modifies this effect. Socioeconomic policies and support for vulnerable families may help reduce rates of infant mortality.