Hypertensive disorders of pregnancy tied to CV mortality after both twin and singleton pregnancies

Netherlands: A retrospective cohort study results showed that women after both twin and singleton pregnancies complicated by HDP (Hypertensive disorders of pregnancy) are at increased risk of CVM (cardiovascular mortality) later in life. The study was published in Pregnancy Hypertension.

Cardiovascular disease continues to be the leading cause of death in women in the Western world and also in India. Hypertensive disorders of pregnancy (HDP) are associated with an increased risk of maternal cardiovascular morbidity and mortality later in life in women.

Recent data illustrates, that CVM risk, ten years after a singleton pregnancy complicated by HDP is increased by two- to threefold as compared to an uncomplicated one.

Petra M. of the Department of Obstetrics and Gynecology, the Netherland, and colleagues conducted this study with the objective to describe CVM risk in women after twin vs singleton pregnancies complicated by HDP. Nulliparous women with a twin or singleton pregnancy who delivered in the Netherlands(1995 -2015) were included in this study.

The research team determined Baseline data, the occurrence of HDP and CVM using data from the Perinatal Registry of the Netherlands and the National Death Registry .1,243,231 nulliparous women were included, of which 30,623 (2.5%) had a twin and 1,212,608 (97.5%) had a singleton pregnancy. A total of 9,853 (32.2%) twin pregnancies were complicated by HDP, versus 249,141 (20.6%) singleton pregnancies. 

In the two main analyses team compared twin pregnancies complicated by HDP to 1) singleton pregnancies complicated by HDP and 2) uncomplicated twin pregnancies (i.e. without HDP) of women who delivered within a hospital setting.

CVM risk using cox-proportional hazard models, adjusted for maternal age (aHR) was set as the main outcome measure.

Key findings from research data were,

• Within the HDP twin cohort, 14/73 (19.2%) maternal deaths were due to cardiovascular causes, versus 335/1,788 (18.7%) in the HDP singleton cohort and 10/117 (8.6%) in the uncomplicated twin cohort

• The corresponding aHR was 2.85 for the HDP twin versus the uncomplicated twin cohort, and 1.05 for the HDP twin versus the HDP singleton cohort.

The research team concluded that women with both twin pregnancies and singleton pregnancies complicated by HDP are at an increased risk of CVM. It is not clear to what extent HDP contributes to an additional CVM risk occurrence at a later age, as pre-pregnancy baseline data such as the presence of cardiovascular disease were not included in the study. Routine assessment of the cardiovascular risk profile of these women will help detect risk factors and prevent cardiovascular disease at an early stage.

The authors suggested the need for future studies to perform analyses of data at the participant level including risk factors to assess the matter of independence of the effect of HDP on CVM.

Reference:

van Baar PM, Welters SM, Ravelli ACJ, de Boer MA, de Groot CJM. Cardiovascular mortality risk a decade after twin and singleton pregnancies complicated by hypertensive disorders of pregnancy. Pregnancy Hypertens. 2022 Feb 2;28:9-14. doi: 10.1016/j.preghy.2022.01.009. Epub ahead of print. PMID: 35149273.