Highlights
This prospective cohort study of 142 first-time mothers with preterm hypertensive disorders of pregnancy (HDP) demonstrates that extended latency between HDP diagnosis and delivery—while not affecting overall cardiovascular health scores—may predispose women to adverse subclinical markers of cardiovascular disease. Specifically, women with longer latency showed elevated high-sensitivity C-reactive protein levels and altered non-HDL cholesterol profiles 2 to 7 years postpartum. These findings suggest that the timing of expectant management in preterm HDP carries implications for long-term cardiovascular risk stratification, even in the absence of overt disease.
Background: The Lasting Legacy of Pregnancy Complications
Hypertensive disorders of pregnancy—including gestational hypertension and preeclampsia—affect approximately 5 to 10 percent of all pregnancies worldwide, representing one of the leading causes of maternal and fetal morbidity and mortality. For decades, clinicians have recognized that women with HDP history face substantially elevated lifetime cardiovascular disease risk, with meta-analyses demonstrating a two- to fourfold increase in future hypertension, ischemic heart disease, and stroke. However, the mechanisms driving this elevated risk remain incompletely understood, and current risk prediction models inadequately capture the unique hemodynamic and metabolic perturbations occurring during pregnancy.
The nuMoM2b (Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be) Heart Health Study was designed to address this critical knowledge gap by prospectively tracking cardiovascular health indicators in first-time mothers years after delivery. The study’s unique focus on latency—the interval between HDP diagnosis and delivery—provides a novel lens through which to examine how the duration of maternal-fetal exposure to hypertensive pathophysiology might influence long-term vascular health. This investigation is particularly timely given the growing emphasis on life course approaches to cardiovascular disease prevention and the recognition that pregnancy may serve as a stress test for women’s future cardiovascular health.
Study Design and Methods
This secondary analysis drew from the nuMoM2b Heart Health Study, a prospective cohort study that enrolled nulliparous women during their first pregnancy and followed them for cardiovascular assessments 2 to 7 years after delivery. The study design incorporated rigorous adjudication of pregnancy outcomes and standardized measurement of cardiovascular risk factors.
Eligible participants included women diagnosed with HDP before 37 weeks of gestation who did not have pregestational hypertension or diabetes. This exclusion of women with pre-existing cardiometabolic conditions ensured that observed differences could be attributed to pregnancy-related factors rather than underlying chronic disease. The final analytical cohort comprised 142 participants, who were stratified by latency duration: short latency (2 to 7 days, n=30) versus long latency (greater than 7 days, n=112). The median latency in the long-latency group was 17.5 days, with an interquartile range of 9 to 35 days.
The primary outcome was the American Heart Association’s Life’s Essential 8 health factor score, assessed 2 to 7 years after delivery. This composite metric incorporates four modifiable health factors: body mass index, blood pressure, non-high-density lipoprotein (non-HDL) cholesterol, and hemoglobin A1C. Secondary outcomes included high-sensitivity C-reactive protein (hs-CRP) and N-terminal probrain natriuretic peptide (NT-proBNP), which serve as biomarkers of systemic inflammation and cardiac strain, respectively.
Statistical analyses employed multivariable linear regression models adjusted for prespecified covariates including age, race/ethnicity, baseline socioeconomic factors, and baseline health status. Sensitivity analyses specifically examined early-onset HDP (diagnosed before 34 weeks) and severe HDP subtypes to determine whether these more aggressive phenotypes accounted for observed latency-related differences.
Key Findings
The principal finding of this investigation reveals a nuanced relationship between HDP latency and cardiovascular risk. In adjusted regression models, longer latency was not associated with the overall Life’s Essential 8 health factor score (β=-0.26, 95 percent CI, -0.94 to 0.41; P=.44), indicating that expectant management duration did not translate into measurable differences in the composite cardiovascular health metric at 2 to 7 years postpartum.
However, examination of individual components uncovered significant associations that suggest subclinical pathophysiology. Longer latency was significantly associated with lower non-HDL cholesterol scores (β=-1.36, 95 percent CI, -2.50 to -0.21; P=.02), a finding that on initial consideration might appear protective. Yet in the context of HDP pathophysiology, lower non-HDL scores in the setting of pregnancy complications may reflect more complex metabolic dysregulation rather than favorable lipid profiles. The clinical significance of this counterintuitive association warrants further investigation in mechanistic studies.
More clinically meaningful was the association between longer latency and elevated high-sensitivity CRP concentrations (β=0.05 log[mg/dL], 95 percent CI, 0.001-0.10; P=.04). This modest but statistically significant elevation in systemic inflammatory markers suggests that women experiencing longer intervals between HDP diagnosis and delivery may harbor heightened chronic inflammation—a well-established driver of atherosclerosis and cardiovascular disease progression. Notably, NT-proBNP concentrations did not differ between latency groups, suggesting that cardiac strain markers remain stable regardless of expectant management duration.
Sensitivity analyses examining early-onset HDP and severe HDP subtypes demonstrated that these more aggressive phenotypes did not account for the observed latency-related differences. This finding implies that latency effects operate independently of HDP severity, potentially through distinct biological pathways related to the duration of maternal exposure to placental factors or hemodynamic stress.
Interpretation and Clinical Implications
These findings contribute to the emerging understanding that hypertensive disorders of pregnancy are not isolated obstetric events but rather harbingers of long-term cardiovascular vulnerability. The dissociation between overall Life’s Essential 8 scores and specific subclinical markers is particularly noteworthy. While composite cardiovascular health scores remain clinically important for population-level risk assessment, they may fail to capture early pathological changes occurring at the vascular and inflammatory level—changes that precede overt cardiovascular disease by years or decades.
The association between longer latency and elevated hs-CRP aligns with established pathophysiology linking chronic inflammation to atherosclerotic plaque development and progression. Women with longer expectant management periods may experience prolonged exposure to factors that perturb vascular endothelium, trigger inflammatory cascades, and establish a proatherogenic milieu. Whether this elevated inflammatory state translates into clinically meaningful cardiovascular events over decades remains uncertain but biologically plausible.
From a clinical standpoint, these findings suggest that women with HDP—particularly those with extended latency between diagnosis and delivery—may benefit from enhanced cardiovascular surveillance beyond current standard recommendations. While universal screening of all women with HDP history remains controversial, identification of those with longer latency could inform risk stratification and guide targeted lifestyle or pharmacological interventions to mitigate long-term cardiovascular risk.
Expert Commentary and Limitations
Several limitations merit consideration when interpreting these findings. The relatively modest sample size of 142 participants limits statistical power for detecting smaller effect sizes and precludes robust subgroup analyses beyond the reported sensitivity assessments. The observational design precludes causal inference; longer latency may reflect underlying disease severity or maternal-fetal factors that independently drive both expectant management duration and cardiovascular risk. Residual confounding cannot be excluded despite careful covariate adjustment. Additionally, the 2- to 7-year follow-up interval, while providing substantial postpartum duration, may not capture the full trajectory of cardiovascular risk that manifests over decades.
The generalizability of findings to multiparous women, women with pregestational comorbidities, or populations with different healthcare access and HDP management protocols remains uncertain. Expectant management practices vary substantially across institutions and clinical contexts, potentially influencing latency distributions and associated outcomes. Future studies should incorporate longer follow-up periods, larger diverse cohorts, and mechanistic investigations to elucidate the biological pathways linking HDP latency to cardiovascular pathophysiology.
Despite these limitations, this study represents a valuable contribution to the growing body of literature examining pregnancy as a window to women’s cardiovascular health. The prospective design, rigorous outcome adjudication, and focused examination of latency as a novel exposure variable provide insights that advance the field’s understanding of HDP-related cardiovascular risk.
Conclusion
This prospective cohort study demonstrates that longer latency of expectant management in preterm hypertensive disorders of pregnancy is associated with adverse subclinical inflammatory and lipid measures 2 to 7 years after delivery, even in the absence of differences in overall cardiovascular health scores. These findings suggest that extended exposure to hypertensive pathophysiology during pregnancy may contribute to long-term vascular vulnerability through inflammatory and metabolic mechanisms. Women with HDP history—particularly those with longer latency—may warrant enhanced cardiovascular risk surveillance and early intervention strategies. Future research should focus on mechanistic pathways, longer-term follow-up, and translation of these findings into clinical risk prediction tools that incorporate pregnancy-related risk factors.
Funding and Registration
The nuMoM2b Heart Health Study was supported by the National Heart, Lung, and Blood Institute (NHLBI). The original nuMoM2b study was registered at ClinicalTrials.gov (NCT01369329).