Date Published: June 12, 2019
Publisher: Public Library of Science
Author(s): Stine Fossum, Øyvind Næss, Sigrun Halvorsen, Grethe S. Tell, Åse V. Vikanes, Clive J. Petry.
To investigate whether exposure to hyperemesis gravidarum (hyperemesis) is associated with subsequent maternal cardiovascular morbidity.
Nationwide cohort study.
Medical Birth Registry of Norway (1967–2002) linked to the nationwide Cardiovascular Disease in Norway project 1994–2009 (CVDNOR) and the Cause of Death Registry.
Women in Norway with singleton births from 1967 to 2002, with and without hyperemesis, were followed up with respect to cardiovascular outcomes from 1994 to 2009.
Cox proportional hazards regression model was applied to estimate hazard ratios (HRs) with 95% confidence interval (CI).
The first hospitalisation due to nonfatal stroke, myocardial infarction or angina pectoris, or cardiovascular death.
Among 989 473 women with singleton births, 13 212 (1.3%) suffered from hyperemesis. During follow-up, a total of 43 482 (4.4%) women experienced a cardiovascular event. No association was found between hyperemesis and the risk of a fatal or nonfatal cardiovascular event (adjusted HR 1.08; 95% CI 0.99–1.18). Women with hyperemesis had higher risk of hospitalisation due to angina pectoris (adjusted HR 1.28; 95% CI 1.15–1.44). The risk of cardiovascular death was lower among hyperemetic women in age-adjusted analysis (HR 0.73; 95% CI 0.59–0.91), but the association was no longer significant when adjusting for possible confounders.
Women with a history of hyperemesis did not have increased risk of a cardiovascular event (nonfatal myocardial infarction or stroke, angina pectoris or cardiovascular death) compared to women without.
Both the European and American guidelines for prevention of cardiovascular disease (CVD) in women now include pregnancy-related complications, such as preeclampsia and pregnancy-induced hypertension, as risk factors [1,2]. CVD is the leading cause of death in women [2,3] and early detection of individuals at risk may prevent major cardiovascular events. Pregnancy-related risk factors for CVD provide such an opportunity.
Among 1 018 478 women with singleton births during 1967–2002, 9 044 (0.9%) emigrated and 9 690 (1.0%) died before start of follow-up. Less than 1.5% had missing information on covariates and only complete cases were used for analyses (Fig 1). The study sample comprised 989 473 women, of which 13 212 (1.3%) had suffered from hyperemesis in at least one pregnancy. The median follow-up time was 15 years (range 0–15) and total person-years at risk were 13 527 714. Lost to follow-up because of emigration was 10 360 (1.1%) women and 20 719 (2.1%) women were censored due to death from other causes during follow-up (1994–2009). Women with a history of hyperemesis were younger at their first registered pregnancy and were less often of ethnic Norwegian origin compared to women without hyperemesis. There was no difference between the two exposure groups in the proportion of women with pre-gestational diabetes mellitus or pre-gestational hypertension. Women with a history of hyperemesis were younger at start of follow-up. At the end of follow-up, women with previous hyperemesis were younger, had obtained a higher level of education and were more often multipara, compared to women without hyperemesis (Table 1).
In this large nationwide cohort study, we found no evidence of increased risk of a cardiovascular event (nonfatal myocardial infarction or stroke, angina pectoris or cardiovascular death) in women with a history of hyperemesis compared to women without.