Medical and Obstetric Complications among Pregnant Women Aged 45 and Older

OBJECTIVE The number of women aged 45 and older who become pregnant is increasing. The objective of this study was to estimate the risk of medical and obstetric complications among women aged 45 and older. METHODS The Nationwide Inpatient Sample was used to identify pregnant woman during admission for delivery. Deliveries were identified using International Classification of Diseases, Ninth Revision (ICD-9-CM) codes. Using ICD-9-CM codes, pre-existing medical conditions and medical and obstetric complications were identified in women at the time of delivery and were compared for women aged 45 years and older to women under age 35. Outcomes among women aged 35-44 were also compared to women under age 35 to determine if women in this group demonstrated intermediate risk between the older and younger groups. Logistic regression analyses were used to calculate odds ratios with 95% confidence intervals for pre-existing medical conditions and medical and obstetric complications for both older groups relative to women under 35. Multivariable logistic regression analyses were also developed for outcomes at delivery among older women, while controlling for pre-existing medical conditions, multiple gestation, and insurance status, to determine the effect of age on the studied outcomes. RESULTS Women aged 45 and older had higher adjusted odds for death, transfusion, myocardial infarction/ischemia, cardiac arrest, acute heart failure, pulmonary embolism, deep vein thrombosis, acute renal failure, cesarean delivery, gestational diabetes, fetal demise, fetal chromosomal anomaly, and placenta previa compared to women under 35. CONCLUSION Pregnant women aged 45 and older experience significantly more medical and obstetric complications and are more likely to die at the time of a delivery than women under age 35, though the absolute risks are low and these events are rare. Further research is needed to determine what associated factors among pregnant women aged 45 and older may contribute to these findings.