Association Between Fetal Congenital Heart Defects and Maternal Risk of Hypertensive Disorders of Pregnancy in the Same Pregnancy and Across Pregnancies.

BACKGROUND: Both pregnant women carrying fetuses with heart defects and women with hypertensive disorders of pregnancy often exhibit angiogenic imbalances, suggesting that the same mechanisms are involved in the pathogenesis of the former and the pathophysiology of the latter. We conducted a register-based cohort study to determine whether offspring congenital heart defects are associated with an increased risk of hypertensive disorders of pregnancy and whether the mechanisms driving any association are primarily maternal or fetal. METHODS: Among singleton pregnancies without chromosomal abnormalities lasting ≥20 weeks in Denmark from 1978 to 2011 (n= 1 972 857), we identified pregnancies complicated by offspring congenital heart defects or early preterm preeclampsia, late preterm preeclampsia, term preeclampsia, and gestational hypertension. We used polytomous logistic regression to estimate odds ratios (ORs) for associations between offspring congenital heart defects and maternal hypertensive disorders of pregnancy overall and for specific heart defects. RESULTS: Offspring congenital heart defects were strongly associated with early preterm preeclampsia (OR, 7.00; 95% confidence interval [CI], 6.11-8.03) and late preterm preeclampsia (OR, 2.82; 95% CI, 2.38-3.34) in the same pregnancy and weakly associated with term preeclampsia (OR, 1.16; 95% CI, 1.06-1.27), but they were not associated with gestational hypertension (OR, 1.07; 95% CI, 0.92-1.25). Association strengths were consistent across heart defect types. Offspring congenital heart defects in a previous pregnancy were also strongly associated with preterm preeclampsia in subsequent pregnancies (early preterm preeclampsia: OR, 2.37; 95% CI, 1.68-3.34; late preterm preeclampsia: OR, 2.04; 95% CI, 1.52-2.75) but were only modestly associated with term preeclampsia and not associated with gestational hypertension. Similarly, preterm preeclampsia in a previous pregnancy, but not term preeclampsia or gestational hypertension, was associated with offspring congenital heart defects in later pregnancies (early preterm preeclampsia: OR, 7.91; 95% CI, 6.06-10.3; late preterm preeclampsia: OR, 2.83; 95% CI, 2.11-3.79; term preeclampsia: OR, 0.98; 95% CI, 0.88-1.10; gestational hypertension: OR, 1.13; 95% CI, 0.92-1.38). CONCLUSIONS: Linked pathophysiological mechanisms may be involved in some congenital heart defects and preterm preeclampsia. The strong associations across pregnancies support a predominantly maternal origin of effect.

Association between pregnancy losses in women and risk of atherosclerotic disease in their relatives: a nationwide cohort study†.

AIMS: A common underlying mechanism with a genetic component could link pregnancy losses with vascular disease. We examined whether pregnancy losses (miscarriages and stillbirths) and atherosclerotic outcomes co-aggregated in families. METHODS AND RESULTS: Using Danish registers, we identified women with pregnancies in 1977-2008, and their parents (>1 million) and brothers (>435 000). We followed parents for incident ischaemic heart disease (IHD), myocardial infarction (MI), and cerebrovascular infarction (CVI), and brothers for a broader combined atherosclerotic endpoint. Using Cox regression, we estimated hazard ratios (HRs) for each outcome by history of pregnancy loss in daughters/sisters. Overall, parents whose daughters had 1, 2, and ≥3 miscarriages had 1.01 [95% confidence interval (CI) 0.99-1.04], 1.07 (95% CI 1.02-1.11), and 1.10 (95% CI 1.02-1.19) times the rate of MI, respectively, as parents whose daughters had no miscarriages. For parents with ≥3 daughters, the HRs were 1.12 (95% CI 1.02-1.24), 1.29 (95% CI 1.13-1.48), and 1.33 (95% CI 1.12-1.57). Effect magnitudes did not differ for fathers and mothers. We observed similar patterns for IHD and CVI (parents) and the atherosclerotic endpoint (brothers). Parents whose daughters had stillbirths had 1.14 (95% CI 1.05-1.24) and 1.07 (95% CI 0.96-1.18) times the rates of MI and CVI, respectively, as parents whose daughters had no stillbirths. CONCLUSION: Certain pregnancy losses and atherosclerotic diseases in both heart and brain may have a common aetiologic mechanism. Women in families with atherosclerotic disease may be predisposed to pregnancy loss; conversely, pregnancy losses in first-degree relatives may have implications for atherosclerotic disease risk.

Hypertensive disorders of pregnancy and subsequent risk of solid cancer--A nationwide cohort study.

Women with hypertensive disorders of pregnancy (HDP) have higher levels of antiangiogenic growth factors during pregnancy than women with normotensive pregnancies. Since angiogenesis is necessary for solid cancer growth and spread, we hypothesized that women with a history of HDP might have a reduced risk of solid cancers (cancers other than lymphomas, hematologic cancers and nonmelanoma skin cancers) later in life. In a register-based cohort study of 1.08 million women giving birth at least once between 1978 and 2011, we used Cox regression to estimate hazard ratios (HRs) comparing solid cancer rates for women with and without a history of HDP. In this cohort, 68,236 women (6.3%) had ≥1 pregnancy complicated by HDP and 42,236 women (3.9%) developed solid tumors during follow-up. A history of HDP was not associated with a clinically meaningful reduction in the overall rate of solid cancer (HR 0.96, 95% confidence interval 0.92-1.00), regardless of HDP severity or time since HDP, nor was there a general tendency toward reduced solid cancer rates across organ sites. A history of HDP was only significantly associated with decreased rates of breast and lung cancers and with increased rates of endometrial and urinary tract cancers. Overall, our results do not support the hypothesis that women with a history of HDP have a reduced overall risk of solid cancer due to a persistent post-HDP antiangiogenic state or an innate tendency toward antiangiogenesis. Observed associations with specific cancers may instead be due to other pregnancy-related mechanisms or to residual/unmeasured confounding.

Association Between Hypertensive Disorders of Pregnancy and Later Risk of Cardiomyopathy.

IMPORTANCE: Women with hypertensive disorders of pregnancy, preeclampsia in particular, have an increased risk of cardiomyopathy during the peripartum period. Whether hypertensive disorders of pregnancy are also associated with cardiomyopathy later in life is unknown. OBJECTIVE: To determine whether hypertensive disorders of pregnancy are associated with cardiomyopathy beyond the peripartum period. DESIGN, SETTING, AND PARTICIPANTS: Nationwide register-based cohort study using Cox regression to compare rates of cardiomyopathy in women with and without a history of hypertensive disorders of pregnancy in a cohort of 1,075,763 women with at least 1 pregnancy ending in live birth or stillbirth in Denmark, 1978-2012, with follow-up through December 31, 2012. EXPOSURES: A hypertensive disorder of pregnancy (severe or moderate preeclampsia or gestational hypertension) registered in the National Patient Register. MAIN OUTCOMES AND MEASURES: Cardiomyopathy more than 5 months after delivery (outside the peripartum period) up to 34 years 7 months. RESULT: The women in the primary cohort had 2,067,633 eligible pregnancies during the study period, 76,108 of which were complicated by a hypertensive disorder of pregnancy. During follow-up, 1577 women (mean age, 48.5 years at cardiomyopathy diagnosis; 2.6% with multiple pregnancies) developed cardiomyopathy. Compared with women with normotensive pregnancies (18,211,603 person-years of follow-up; n = 1408 cardiomyopathy events, 7.7/100,000 person-years [95% CI, 7.3-8.2]), women with a history of hypertensive disorders of pregnancy had significantly increased rates of cardiomyopathy (in 173,062 person-years of follow-up among women with severe preeclampsia, n = 27 cardiomyopathy events; 15.6/100,000 person-years [95% CI, 10.7-22.7]; adjusted hazard ratio [HR], 2.20 [95% CI, 1.50-3.23]; in 697,447 person-years of follow-up among women with moderate preeclampsia, n = 102 cardiomyopathy events; 14.6/100,000 person-years [95% CI, 12.0-17.8]; adjusted HR, 1.89 [95% CI, 1.55-2.23]; in 213,197 person-years of follow-up among women with gestational hypertension, n = 40 cardiomyopathy events; 17.3/100,000 person-years [95% CI, 12.7-23.6]; adjusted HR, 2.06 [95% CI, 1.50-2.82]). These increases persisted more than 5 years after the latest pregnancy. Mediation analyses suggested that only about 50% of the association was an indirect association through postpregnancy chronic hypertension. In this cohort, 11% of all cardiomyopathy events occurred in women with a history of hypertensive disorders of pregnancy. CONCLUSIONS AND RELEVANCE: Women with a history of hypertensive disorders of pregnancy, compared with women without such a history, had a small but statistically significant increased risk of cardiomyopathy more than 5 months after delivery. Further research is necessary to understand whether there is a causal mechanism behind this association.

Hypertensive disorders of pregnancy and peripartum cardiomyopathy: A nationwide cohort study.

BACKGROUND: Peripartum cardiomyopathy (PPCM) is a serious cardiac disorder occurring late in pregnancy or early in the postpartum period. We examined associations between hypertensive disorders of pregnancy (HDP: preeclampsia and gestational hypertension) and PPCM, accounting for other pregnancy-related risk factors for PPCM. METHODS: Using nationwide Danish register data, we constructed a cohort of all women with ≥1 live birth or stillbirth in Denmark between 1978 and 2012. Using log-linear binomial regression and generalized estimating equations, we estimated risk ratios (RRs) for PPCM associated with HDP of varying severity. RESULTS: In a cohort of 1,088,063 women with 2,078,822 eligible pregnancies, 126 women developed PPCM (39 in connection with an HDP-complicated pregnancy). The risks of PPCM were significantly higher in women with HDP-complicated pregnancies than in women with normotensive pregnancies (severe preeclampsia, RR 21.2, 95% confidence interval [CI] 12.0-37.4; moderate preeclampsia, RR 10.2, 95% CI 6.18-16.9; gestational hypertension, RR 5.16, 95% CI 2.11-12.6). The RRs for moderate preeclampsia and gestational hypertension were not significantly different from one another (p = 0.18); the RR for severe preeclampsia was significantly different from the RR for moderate preeclampsia and gestational hypertension combined (p = 0.02). CONCLUSIONS: Although 70% of PPCM occurred in women with normotensive pregnancies, HDPs were associated with substantial increases in PPCM risk that depended on HDP severity. The heart's capacity to adapt to a normal pregnancy may be exceeded in some women already susceptible to cardiac insult, contributing to PPCM. HDPs, severe preeclampsia in particular, probably represent an additional cardiac stressor during pregnancy.

Risk of post-pregnancy hypertension in women with a history of hypertensive disorders of pregnancy: nationwide cohort study.

Objectives To determine how soon after delivery the risk of post-pregnancy hypertension increases in women with hypertensive disorders of pregnancy and how the risk evolves over time.Design Nationwide register based cohort study.Setting Denmark.Populations 482 972 primiparous women with a first live birth or stillbirth between 1995 and 2012 (cumulative incidence analyses), and 1 025 118 women with at least one live birth or stillbirth between 1978 and 2012 (Cox regression analyses).Main outcome measures 10 year cumulative incidences of post-pregnancy hypertension requiring treatment with prescription drugs, and hazard ratios estimated using Cox regression.Results Of women with a hypertensive disorder of pregnancy in a first pregnancy in their 20s, 14% developed hypertension in the first decade post partum, compared with 4% of women with normotensive first pregnancies in their 20s. The corresponding percentages for women with a first pregnancy in their 40s were 32% and 11%, respectively. In the year after delivery, women with a hypertensive disorder of pregnancy had 12-fold to 25-fold higher rates of hypertension than did women with a normotensive pregnancy. Rates in women with a hypertensive disorder of pregnancy were threefold to 10-fold higher 1-10 years post partum and remained twice as high even 20 or more years later.Conclusions The risk of hypertension associated with hypertensive disorders of pregnancy is high immediately after an affected pregnancy and persists for more than 20 years. Up to one third of women with a hypertensive disorder of pregnancy may develop hypertension within a decade of an affected pregnancy, indicating that cardiovascular disease prevention in these women should include blood pressure monitoring initiated soon after pregnancy.