Adverse Birth Outcomes Among Women of Advanced Maternal Age With and Without Health Conditions in Maryland.

Background: Advanced maternal age (AMA) has been linked to both higher risk of adverse birth outcomes and higher levels of comorbidities. It is unclear if adverse outcomes are higher for older healthy women. This study examined the association between AMA and adverse birth outcomes among women with and without preexisting and pregnancy-related health conditions.

Methods: Analysis of data for 14,933 singleton births between 2004 and 2015 from the population-based Maryland Pregnancy Risk Assessment Monitoring System was conducted, comparing women aged 20-34 years and 35 years and older. Multivariable logistic regression estimated the difference in odds of preterm birth (PTB) and low birthweight (LBW) by age group among women with and without health conditions. The analysis of women without health conditions was stratified by parity.

Results: Among women without health conditions, AMA was associated with higher odds of PTB regardless of birthweight, LBW regardless of term, LBW term births, and LBW PTBs; stratified analysis showed higher risk of these outcomes among both older primiparas and multiparas. Compared with younger women with hypertensive disorders, older women with similar health conditions had higher odds of PTB regardless of birthweight. Older women with asthma had higher odds of LBW term births.

Conclusions: AMA is associated with adverse birth outcomes among women with and without health conditions compared with younger women with similar health status. Improved screening and management of health conditions during pregnancy is needed for older women, regardless of parity.