Pregnancy as a Window to Future Health

Cardiovascular disease (CVD) is the leading cause of mortality among women in the United States and developed countries. Women on average experience CVD mortality about 10 years later than men. However, women experience a higher fatality rate following a first myocardial infarction, and despite an overall decline in the CVD death rate in the United States, the rate of decline has been slower for women compared with men. In addition, the death rate is 70% higher in African-American women compared with White women. Two-thirds of coronary heart disease sudden deaths occur in women with no previous symptoms, compared with one-half of sudden deaths in men. It is now evident that this excess mortality is due in part to an increased death rate among premenopausal women, although little is known regarding coronary artery disease among this group. From 1995 to 2014, myocardial infarction (MI) hospitalizations increased in young women but not in men; relative to men, young women with MI had a higher comorbidity index and a lesser likelihood of being managed with guideline-based medications. Also, young women hospitalized for MI have relatively more comorbidities and inpatient mortality and poorer health status 1 year later. High rates of overweight/obesity (∼55%) and elevated blood pressure (BP) in young women likely contribute to this disparity. ^, There is also evidence that hypertriglyceridemia, low high-density lipoprotein cholesterol, hyperinsulinemia, inflammation, central adiposity, and hypertension are more strongly related to heart disease risk among women compared with men. ^, Women’s risk for CVD increases after menopause, although indistinguishable from aging; however, risk factors that are elevated premenopause increase proportionally postmenopause. Thus detection of elevated risk during reproductive years may provide a critical opportunity to delay or prevent onset of CVD in women.

Healthy pregnancy requires profound maternal vascular, immune, and metabolic adaptations to support placentation and fetal growth (discussed in detail in Chapters 8 and 10 ). It is now well established that an impaired ability to mount these adaptations contributes to adverse pregnancy outcomes (APOs) such as preeclampsia, preterm birth, fetal growth restriction, stillbirth, and gestational diabetes mellitus (GDM). Indeed, pregnancy now can be viewed as a “stress test” of these systems, with APOs being a harbinger of excess cardiometabolic risk and CVD morbidity and mortality ( Fig. 72.1A ). Leveraging this possibility may help mitigate this high-risk trajectory and delay or prevent CVD in women (see Fig. 72.1B ), and new guidelines identify women with APOs as a high-risk group for CVD.

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Pregnancy is a “stress test” that can reveal subclinical trajectories and identify new opportunities for chronic disease prevention.

(A) Women at high risk for future cardiovascular disease are identifiable during pregnancy, at which point subclinical vascular risk may become clinically evident. (B) The risk revealed by pregnancy can be used to target high-risk women for screening and early intervention by lifestyle modification and treatment, altering their chronic disease trajectory as they enter midlife.

Data from Rich-Edwards JW, McElrath TF, Karumanchi SA, Seely EW. Breathing life into the lifecourse approach: pregnancy history and cardiovascular disease in women. Hypertension. 2010;56:331–334; Sattar N, Greer IA. Pregnancy complications and maternal cardiovascular risk: opportunities for intervention and screening? BMJ. 2002;325:157–160.

Hypertension

Hypertension is common in women, accounts for a significant proportion of CVD, and often goes undetected. Early detection of hypertension is critical, as treatment is widely available, inexpensive, and cardioprotective. Yet, up to 38% of stage 2 hypertension goes undetected before 40 years of age. Hypertension contributes to more CVD events in women relative to men (32% versus 19% of CVD events are attributable to hypertension, P = . 02; Fig. 72.2 ). Short of hypertension, the accumulation of modest BP elevations over young adulthood is linked to atherosclerosis, coronary calcification, and higher left ventricular mass. The prevalence of hypertension during the reproductive years has doubled due to the newest guidelines that define stage 1 hypertension as blood pressure above 130/80 mm Hg, and young adults (younger than age 40) with stage 1 or stage 2 hypertension have excess risk for CVD events later in life. Notably, recent analyses reveal that BP trajectories in women evaluated over the life course in a sex-stratified fashion increase more rapidly than in men, beginning as early as in the third decade of life. These findings have implications for later-life cardiac and vascular diseases that often present differently in women compared with men. Women also have evidence of impaired coronary flow reserve, a marker of target-organ damage that may precede coronary artery disease. As noted by the Institute of Medicine (now named the National Academy of Medicine), optimizing BP in younger populations has tremendous opportunity to prevent premature morbidity and mortality. Pregnancy care is (mostly) universally accessible, and the access to care available during pregnancy may not be paralleled again until 65 years of age. Over 80% of women in the United States bear a child. Pregnancy is a unique opportunity to assess CVD risk in women.