LAS VEGAS – Women who develop any form of hypertensive disease during pregnancy have a significantly increased mortality rate until they reach age 50, compared with women without the condition.
The findings, presented at the annual Pregnancy Meeting sponsored by the Society for Maternal-Fetal Medicine, are based on a review of more than 2 million mothers who delivered babies in Utah during 1939-2012.
The relatively increased mortality rate linked with hypertensive disease of pregnancy (HDP) reached its peak during the first decade immediately following the index delivery and was dramatically higher in women for whom the index HDP was preceded by at least one earlier HDP. Increased mortality was especially elevated for certain types of deaths including stroke, diabetes, circulatory disease, and ischemic heart disease, said, a maternal-fetal medicine researcher at the University of Utah in Salt Lake City.
She calculated that during the decade following an index case of HDP, life expectancy among mothers who had two or more HDP-affected pregnancies was about 49 years, life expectancy among women with a history of one HDP was 52 years, and postpartum women without HDP had a life expectancy of 55 years.
The data came from 2,083,331 singleton pregnancies delivered in Utah during 1939-2012 where the mother remained in Utah for at least 1 year following delivery. From this group, Dr. Theilen and her associates identified 67,384 women (3%) with HDP, including 49,598 women without a prior history of HDP and 7,786 with at least one prior HDP pregnancy. They included four different diagnoses as HDP: gestational hypertension, preeclampsia, HELLP syndrome (hemolysis, elevated liver enzymes, and low platelet count), or eclampsia.
The analysis excluded women with chronic hypertension, antiphospholipid syndrome, pregestational diabetes, or chronic kidney disease. It also excluded women who died within a year of the index delivery. For each of the included 67,384 cases with HDP, the researchers selected two controls with a delivery unaffected by HDP and matched them to a case by age, year of childbirth, and parity.
The women in the study were 26 years old on average. Gestational age at delivery among the HDP cases averaged 1 week less than among the controls, 37.8 weeks compared with 38.9 weeks, a statistically significant difference. Average birth weight also differed by a significant amount, 3,079 grams in the HDP neonates and 3,319 grams in the control newborns. During follow-up, 8% of the HDP women died, compared with 6% of the control women.
Analysis showed that relative mortality rates in HDP women were especially elevated for certain types of death: endocrine and metabolic, circulatory, genitourinary, infectious disease, and digestive. In most types of death, the increased risk linked with HDP was markedly higher in the women with recurrent HDP.
Dr. Theilenthe relative risks of death for certain specific mortality causes (Am J Obstet Gynecol. 2017 Jan;216[suppl]:S32-3). In women with a single index case of HDP, the mortality rate compared to women with no HDP was threefold higher for diabetes, twofold higher for ischemic heart disease, and 85% higher for stroke. In women with recurrent HDP, the relative mortality risks were fourfold higher for diabetes, threefold higher for ischemic heart disease, and fivefold higher for stroke.
For all causes of death except stroke, the increased relative risk from HDP existed only for women younger than 51 years. Once HDP women passed the age of 50, their excess mortality risk was substantially muted, even in women with recurrent HDP. But for stroke mortality, the added risk persisted among older women with a history of at least two HDPs. In this subgroup, stroke deaths were nearly fourfold higher than in the matched controls.
Dr. Theilen reported having no financial disclosures.