An Enhanced Postpartum Transition Program to Primary Care.

Background: Gestational diabetes mellitus (GDM) and hypertensive disorders of pregnancy (HDP) are risk factors for future cardiovascular disease, yet few individuals receive postpartum care with primary care clinicians (PCP). To facilitate transitions of care to PCPs and improve cardiovascular health monitoring within the first 13 months postpartum, we developed and piloted an enhanced postpartum referral pathway for patients with GDM or HDP. Methods: Eligible patients included those who received perinatal care at a large, urban, academic medical center, experienced GDM or HDP during their most recent pregnancy, and lacked an existing PCP. Resident, faculty, and advanced practitioners referred patients during antenatal, delivery-related, or postpartum visits. A dedicated scheduler contacted patients to schedule an appointment with a women's health-focused resident or faculty PCP. The percent of patients who attended a postpartum PCP visit, who had an HbA1c and cholesterol panel checked within the first 13 months postpartum, were compared between patients referred and not referred to the program using adjusted odds ratios (aOR). Results: Of 129 individuals referred, 48.1% attended a PCP visit, 31.8% completed cholesterol screening, and 41.9% completed HbA1c screening within 13 months postpartum. After adjusting for age, parity, insurance, and referral indication, referred individuals had greater odds for each outcome (PCP visit: aOR = 6.0, 95% CI 4.0-9.0; cholesterol: aOR = 2.4, 95% 1.6-3.9; HbA1c: aOR = 2.5, 95% CI 1.7-3.7) compared with nonreferred individuals in the same time period. Discussion: A enhanced postpartum PCP referral pathway pilot for birthing individuals was associated with improved follow-up in the first year postpartum.

Predictors of success after in vitro fertilization.

The last few decades have witnessed a rise in the global uptake of in vitro fertilization (IVF) treatment. To ensure optimal use of this technology, it is important for patients and clinicians to have access to tools that can provide accurate estimates of treatment success and understand the contribution of key clinical and laboratory parameters that influence the chance of conception after IVF treatment. The focus of this review was to identify key predictors of IVF treatment success and assess their impact in terms of live birth rates. We have identified 11 predictors that consistently feature in currently available prediction models, including age, duration of infertility, ethnicity, body mass index, antral follicle count, previous pregnancy history, cause of infertility, sperm parameters, number of oocytes collected, morphology of transferred embryos, and day of embryo transfer.

An Age-Period-Cohort Analysis of Cardiovascular Disease Mortality in the United States from 1999 to 2018.

BACKGROUND: Although cardiovascular disease mortality rates in the United States declined from the 1970s to 2010s, they have now plateaued. The independent effects of age, period, and birth year (cohort) on cardiovascular disease mortality have not previously been defined. METHODS: We used data from the Centers for Disease Control and Prevention's Wide-Ranging Online Data for Epidemiologic Research to examine the effects of age, period, and cohort on cardiovascular disease mortality among individuals aged 20-84 years from 1999 to 2018, prior to the onset of the coronavirus disease 2019 pandemic. Age effects were described as cardiovascular disease-related mortality rates in each 5-year age group adjusted for year of death (period) and year of birth (cohort). Period and cohort effects were quantified as adjusted rate ratios (RRs) comparing cardiovascular disease mortality rates in each period and cohort to the reference periods and reference cohort (ie, 1919 birth cohort), respectively. RESULTS: Between 1999 to 2018, there were 10,404,327 cardiovascular disease deaths among US adults. In each individual birth cohort, the age-specific cardiovascular disease mortality rates were stable between ages 20 through 39 years. Age-specific rates were higher for each year older between ages 40 through 84 years adjusting for period effects. The period cardiovascular disease mortality rates were lower in later periods (2004-2008 period RR 0.87, 95% confidence interval [CI] 0.85 to 0.88; 2009-2013 period RR 0.78, 95% CI 0.76 to 0.80) compared with the reference period (1999 to 2003) and plateaued thereafter. The cohort cardiovascular disease mortality rates were progressively lower in more recent birth cohorts (1924 birth cohort RR 0.85, 95% CI 0.83 to 0.87; 1974 birth cohort RR 0.29, 95% CI 0.27 to 0.32) compared with the reference cohort (1919 cohort) and plateaued thereafter. CONCLUSION: Although cardiovascular disease mortality rates declined rapidly among those born between 1919 and 1974, improvements plateaued in birth cohorts thereafter even adjusted for period effects.

Rural-urban disparities in pregestational and gestational diabetes in pregnancy: Serial, cross-sectional analysis of over 12 million pregnancies.

OBJECTIVE: To compare trends in pregestational (DM) and gestational diabetes (GDM) in pregnancy in rural and urban areas in the USA, because pregnant women living in rural areas face unique challenges that contribute to rural-urban disparities in adverse pregnancy outcomes. DESIGN: Serial, cross-sectional analysis. SETTING: US National Center for Health Statistics (NCHS) Natality Files from 2011 to 2019. POPULATION: A total of 12 401 888 singleton live births to nulliparous women aged 15-44 years. METHODS: We calculated the frequency (95% confidence interval [CI]) per 1000 live births, the mean annual percentage change (APC), and unadjusted and age-adjusted rate ratios (aRR) of DM and GDM in rural compared with urban maternal residence (reference) per the NCHS Urban-Rural Classification Scheme overall, and by delivery year, reported race and ethnicity, and US region (effect measure modification). MAIN OUTCOME MEASURES: The outcomes (modelled separately) were diagnoses of DM and GDM. RESULTS: From 2011 to 2019, there were increases in both the frequency (per 1000 live births; mean APC, 95% CI per year) of DM and GDM in rural areas (DM: 7.6 to 10.4 per 1000 live births; APC 2.8%, 95% CI 2.2%-3.4%; and GDM: 41.4 to 58.7 per 1000 live births; APC 3.1%, 95% CI 2.6%-3.6%) and urban areas (DM: 6.1 to 8.4 per 1000 live births; APC 3.3%, 95% CI 2.2%-4.4%; and GDM: 40.8 to 61.2 per 1000 live births; APC 3.9%, 95% CI 3.3%-4.6%). Individuals living in rural areas were at higher risk of DM (aRR 1.48, 95% CI 1.45%-1.51%) and GDM versus those in urban areas (aRR 1.17, 95% CI 1.16%-1.18%). The increased risk was similar each year for DM (interaction p = 0.8), but widened over time for GDM (interaction p < 0.01). The rural-urban disparity for DM was wider for individuals who identified as Hispanic race/ethnicity and in the South and West (interaction p < 0.01 for all); and for GDM the rural-urban disparity was generally wider for similar factors (i.e. Hispanic race/ethnicity, and in the South; interaction p < 0.05 for all). CONCLUSIONS: The frequency of DM and GDM increased in both rural and urban areas of the USA from 2011 to 2019 among nulliparous pregnant women. Significant rural-urban disparities existed for DM and GDM, and increased over time for GDM. These rural-urban disparities were generally worse among those of Hispanic race/ethnicity and in women who lived in the South. These findings have implications for delivering equitable diabetes care in pregnancy in rural US communities.

Cardiovascular Health in the Postpartum Period.

This article in the Women's Health series discusses recent increases in US maternal death rates, disparities in rates by race and ethnicity, poor cardiovascular health (CVH) as one of the multifactorial causes, and clinical approaches to assessing and treating poor CVH postpartum.

Incidence and management of premature rupture of membranes in Victoria, Australia: A retrospective cohort study of 636 590 births between 2009 and 2017.

BACKGROUND: Premature rupture of membranes (PROM) is a complication affecting 7-12% of pregnancies in which fetal chorioamniotic membranes rupture before labour begins. Preterm PROM (PPROM) (ie <37 weeks gestation) precedes one-third of preterm births, exposing the fetus to increased morbidity from placental abruption, respiratory distress syndrome and sepsis. AIM: To analyse trends in the incidence and mode of birth in preterm and term PROM in Victoria, Australia between 2009 and 2017. MATERIALS AND METHODS: This retrospective population-based cohort study included all singleton pregnancies from 2009 to 2017. We examined women with PROM (both <37 weeks (PPROM) and at term). Management was assessed in three categories: (a) expectant management; (b) induction of labour (IOL); and (c) elective caesarean section (elCS). A multinomial logistic regression model was used to adjust for confounders influencing the choice of management. RESULTS: Of 636 590 singleton pregnancies, 52 669 (8.3%) births with PROM at term (42 439; 6.7%) or PPROM (10 230; 1.6%) were identified. Of these, the majority were managed expectantly (n = 22 726; 43.1%), or with IOL (25 931; 49.2%). While elCS represented only 7.6% of these cases (n = 4012), its use rose consistently from 2009 to 2017 for PROM at term and PPROM alike. For women with PPROM at 34-36 weeks the odds of elCS increased by 5% annually (adjusted odds ratio (aOR) 1.05; 95% CI 1.02-1.08) and 2% for IOL (aOR 1.02; 95% CI 1.00-1.05) vs expectant management. CONCLUSIONS: The use of elCS and IOL in PPROM is rising in Victoria, particularly between 34 and 36 completed weeks of pregnancy. Research is needed to determine the drivers for this increase.

Trends in Cardiovascular Health Counseling Among Postpartum Individuals.

Importance: Poor prepregnancy cardiovascular health (CVH) and adverse pregnancy outcomes (APOs) are key risk factors for subsequent cardiovascular disease (CVD) in birthing adults. The postpartum visit offers an opportunity to promote CVH among at-risk individuals. Objective: To determine prevalence, predictors, and trends in self-reported CVH counseling during the postpartum visit. Design, Setting, and Participants: Serial, cross-sectional analysis of data from 2016-2020 from the Pregnancy Risk Assessment Monitoring System (PRAMS), a nationally representative, population-based survey. The primary analysis included individuals who attended a postpartum visit 4 to 6 weeks after delivery with available data on receipt of CVH counseling, self-reported prepregnancy CVD risk factors (obesity, diabetes, and hypertension), and APOs (gestational diabetes, hypertensive disorders of pregnancy, and preterm birth) (N = 167 705 [weighted N = 8 714 459]). Exposures: Total number of CVD risk factors (0, 1, or ≥2 prepregnancy risk factors or APOs). Main Outcomes and Measures: Annual, age-adjusted prevalence of self-reported postpartum CVH counseling per 100 individuals, defined as receipt of counseling for healthy eating, exercise, and losing weight gained during pregnancy, was calculated overall and by number of CVD risk factors. Average annual percent change (APC) assessed trends in CVH counseling from 2016 through 2020. Data were pooled to calculate rate ratios (RRs) for counseling that compared individuals with and without CVD risk factors after adjustment for age, education, postpartum insurance, and delivery year. Results: From 2016 through 2020, prevalence of self-reported postpartum CVH counseling declined from 56.2 to 52.8 per 100 individuals among those with no CVD risk factors (APC, -1.4% [95% CI, -1.8% to -1.0%/y]), from 58.5 to 57.3 per 100 individuals among those with 1 risk factor (APC, -0.7% [95% CI, -1.3% to -0.1%/y]), and from 61.9 to 59.8 per 100 individuals among those with 2 or more risk factors (APC, -0.8% [95% CI, -1.3% to -0.3%/y]). Reporting receipt of counseling was modestly higher among individuals with 1 risk factor (RR, 1.05 [95% CI, 1.04 to 1.07]) and with 2 or more risk factors (RR, 1.11 [95% CI, 1.09 to 1.13]) compared with those who had no risk factors. Conclusions and Relevance: Approximately 60% of individuals with CVD risk factors or APOs reported receiving CVH counseling at their postpartum visit. Prevalence of reporting CVH counseling decreased modestly over 5 years.

Pregnancy as an Early Cardiovascular Moment: Peripartum Cardiovascular Health.

Pregnancy is commonly referred to as a window into future CVH (cardiovascular health). During pregnancy, physiological adaptations occur to promote the optimal growth and development of the fetus. However, in approximately 20% of pregnant individuals, these perturbations result in cardiovascular and metabolic complications, which include hypertensive disorders of pregnancy, gestational diabetes, preterm birth, and small-for-gestational age infant. The biological processes that lead to adverse pregnancy outcomes begin before pregnancy with higher risk of adverse pregnancy outcomes observed among those with poor prepregnancy CVH. Individuals who experience adverse pregnancy outcomes are also at higher risk of subsequent development of cardiovascular disease, which is largely explained by the interim development of traditional risk factors, such as hypertension and diabetes. Therefore, the peripartum period, which includes the period before (prepregnancy), during, and after pregnancy (postpartum), represents an early cardiovascular moment or window of opportunity when CVH should be measured, monitored, and modified (if needed). However, it remains unclear whether adverse pregnancy outcomes reflect latent risk for cardiovascular disease that is unmasked in pregnancy or if adverse pregnancy outcomes are themselves an independent and causal risk factor for future cardiovascular disease. Understanding the pathophysiologic mechanisms and pathways linking prepregnancy CVH, adverse pregnancy outcomes, and cardiovascular disease are necessary to develop strategies tailored for each stage in the peripartum period. Emerging evidence suggests the utility of subclinical cardiovascular disease screening with biomarkers (eg, natriuretic peptides) or imaging (eg, computed tomography for coronary artery calcium or echocardiography for adverse cardiac remodeling) to identify risk-enriched postpartum populations and target for more intensive strategies with health behavior interventions or pharmacological treatments. However, evidence-based guidelines focused on adults with a history of adverse pregnancy outcomes are needed to prioritize the prevention of cardiovascular disease during the reproductive years and beyond.

Oral Contraceptive Pills and Hypertension: A Review of Current Evidence and Recommendations.

Oral contraceptive pills (OCPs) have been used as effective and popular forms of contraception since the middle of the last century. By 2019, over 150 million reproductive-aged individuals were using OCPs to prevent unintended pregnancies worldwide. Safety concerns regarding the effects of OCPs on blood pressure were reported soon after these pills gained approval. Although OCP doses were subsequently reduced, epidemiologic evidence continued to support a smaller, but significant association between OCPs and hypertension. Given the rising prevalence of hypertension, as well as the adverse effects of cumulative exposure to blood pressure elevations on cardiovascular disease risk, understanding the nature of the association between OCPs and hypertension is important for clinicians and patients to assess the risks and benefits of use, and make individualized decisions regarding contraception. Therefore, this review summarizes the current and historical evidence describing the association between OCP use and blood pressure elevations. Specifically, it identifies the pathophysiologic mechanisms linking OCPs to hypertension risk, describes the magnitude of the association between OCPs and blood pressure elevations, and distinguishes the effects of various OCP types on blood pressure. Finally, it describes current recommendations regarding hypertension and OCP use, as well as identifies strategies, such as over-the-counter OCP prescribing, to safely and equitably improve access to oral contraception.

Chronic Hypertension in Pregnancy: A Lens Into Cardiovascular Disease Risk and Prevention.

Hypertension is a major, modifiable risk factor for cardiovascular disease (CVD) in the United States. Over the past decade, the prevalence of chronic hypertension (CHTN) during pregnancy has nearly doubled with persistent race- and place-based disparities. Blood pressure elevations are of particular concern during pregnancy given higher risk of maternal and fetal morbidity and mortality, as well as higher lifetime risk of CVD in birthing individuals with CHTN. When identified during pregnancy, CHTN can, therefore, serve as a lens into CVD risk, as well as a modifiable target to mitigate cardiovascular risk throughout the life course. Health services and public health interventions that equitably promote cardiovascular health during the peripartum period could have an important impact on preventing CHTN and reducing lifetime risk of CVD. This review will summarize the epidemiology and guidelines for the diagnosis and management of CHTN in pregnancy; describe the current evidence for associations between CHTN, adverse pregnancy outcomes, and CVD; and identify opportunities for peripartum care to equitably reduce hypertension and CVD risk throughout the life course.

Rural-Urban Disparities in Adverse Maternal Outcomes in the United States, 2016-2019.

Objectives. To describe differences in maternal admissions to the intensive care unit (ICU) and mortality in rural versus urban areas in the United States. Methods. We performed a nationwide analysis and calculated age-standardized rates and rate ratios (RRs) of maternal ICU admission and mortality per 100 000 live births between 2016 and 2019 in rural versus urban areas. Results. From 2016 to 2019, there was no significant increase in age-standardized rates of maternal ICU admissions in rural (170.6-192.3) or urban (161.7-172.4) areas, with a significantly higher rate, albeit a relatively small difference, in rural versus urban areas (2019 RR = 1.14; 95% confidence interval [CI] = 1.04, 1.20). Maternal mortality increased in both rural (66.9-81.7 deaths per 100 000 live births) and urban (38.1-42.3) areas and was nearly 2 times higher in rural areas (2019 RR = 1.93; 95% CI = 1.71, 2.17). Conclusions. Pregnant individuals in rural areas are at higher risk for ICU admission and mortality than are their urban counterparts. Significant increases in maternal mortality occurred in rural and urban areas. Public Health Implications. Public health efforts need to focus on resource-limited rural areas to mitigate geographic disparities in maternal morbidity and mortality. (Am J Public Health. 2023;113(2): 224-227.https://doi.org/10.2105/AJPH.2022.307134).

Trends in gestational diabetes mellitus among nulliparous pregnant individuals with singleton live births in the United States between 2011 to 2019: an age-period-cohort analysis.

BACKGROUND: The rate of gestational diabetes mellitus has increased over the past decade. An age, period, and cohort epidemiologic analysis can be used to understand how and why disease trends have changed over time. OBJECTIVE: This study aimed to estimate the associations of age (at delivery), period (delivery year), and cohort (birth year) of the pregnant individual with trends in the incidence of gestational diabetes mellitus in the United States. STUDY DESIGN: We conducted an age, period, and cohort analysis of nulliparous pregnant adults aged 18 to 44 years with singleton live births from the National Vital Statistics System from 2011 to 2019. Generalized linear mixed models were used to calculate the adjusted rate ratios for the incidence of gestational diabetes mellitus for each 3-year maternal age span, period, and cohort group compared with the reference group for each. We repeated the analyses with stratification according to self-reported racial and ethnic group (non-Hispanic Asian-Pacific Islander, non-Hispanic Black, Hispanic, and non-Hispanic White) because of differences in the incidence of and risk factors for gestational diabetes mellitus by race and ethnicity. RESULTS: Among 11,897,766 pregnant individuals, 5.2% had gestational diabetes mellitus. The incidence of gestational diabetes mellitus was higher with increasing 3-year maternal age span, among those in the more recent delivery period, and among the younger birth cohort. For example, individuals aged 42 to 44 years at delivery had a 5-fold higher risk for gestational diabetes mellitus than those aged 18 to 20 years (adjusted rate ratio, 5.57; 95% confidence interval, 5.43-5.72) after adjusting for cohort and period. Individuals who delivered between 2017 and 2019 were at higher risk for gestational diabetes mellitus than those who delivered between 2011 and 2013 (adjusted rate ratio, 1.24; 95% confidence interval, 1.23-1.25) after adjusting for age and cohort. Individuals born between 1999 and 2001 had a 3-fold higher risk for gestational diabetes mellitus than those born between 1969 and 1971 (adjusted rate ratio, 3.12; 95% confidence interval, 2.87-3.39) after adjusting for age and period. Similar age, period, and cohort effects were observed for the assessed racial and ethnic groups, with the greatest period effects observed among Asian and Pacific Islander individuals. CONCLUSION: Period and birth cohort effects have contributed to the rising incidence of gestational diabetes mellitus in the United States from 2011 to 2019.

Atherosclerotic Cardiovascular Disease or Heart Failure: First Cardiovascular Event in Adults With Prediabetes and Diabetes.

BACKGROUND: Individuals with prediabetes and diabetes are at increased risk of atherosclerotic cardiovascular disease (ASCVD) and heart failure (HF). Whether ASCVD or HF is more likely to occur first in these populations within different race-sex groups is unknown. OBJECTIVE: To determine the competing risk for the first cardiovascular event by subtype in Black and white men and women with prediabetes and diabetes. METHODS: Individual-level data from adults without ASCVD or HF were pooled from 6 population-based cohorts. We estimated the competing cumulative incidences of ASCVD, HF and noncardiovascular death as the first event in middle-aged (40-59 years) and older (60-79 years) adults, stratified by race and sex, with normal fasting plasma glucose (FPG < 100 mg/dL), prediabetes (FPG 100-125 mg/dL) and diabetes (FPG ≥ 126 mg/dL or on antihyperglycemic agents) at baseline. Within each race-sex group, we estimated risk the adjusted hazard ratio of ASCVD, HF and noncardiovascular death in adults with prediabetes and diabetes relative to adults with normoglycemia after adjusting for cardiovascular risk factors. RESULTS: In 40,117 participants with 638,910 person-years of follow-up, 5781 cases of incident ASCVD and 3179 cases of incident HF occurred. In middle-aged adults with diabetes, competing cumulative incidence of ASCVD as a first event was higher than HF in white men (35.4% vs 11.6%), Black men (31.6% vs 15.1%) and white women (24.3% vs 17.2%) but not in Black women (26.4% vs 28.4%). Within each group, the adjusted hazard ratio of ASCVD and HF was significantly higher in adults with diabetes than in adults with normal FPG levels. Findings were largely similar in middle-aged adults with prediabetes and older adults with prediabetes or diabetes. CONCLUSIONS: Black women with diabetes are more likely to develop HF as their first CVD event, whereas individuals with diabetes from other race-sex groups are more likely to present first with ASCVD. These results can inform the tailoring of primary prevention therapies for either HF- or ASCVD-specific pathways based on individual-level risk.

Social and Psychosocial Determinants of Racial and Ethnic Differences in Cardiovascular Health in the United States Population.

BACKGROUND: Social and psychosocial factors are associated with cardiovascular health (CVH). Our objective was to examine the contributions of individual-level social and psychosocial factors to racial and ethnic differences in population CVH in the NHANES (National Health and Nutrition Examination Surveys) 2011 to 2018, to inform strategies to mitigate CVH inequities. METHODS: In NHANES participants ages ≥20 years, Kitagawa-Blinder-Oaxaca decomposition estimated the statistical contribution of individual-level factors (education, income, food security, marital status, health insurance, place of birth, depression) to racial and ethnic differences in population mean CVH score (range, 0-14, accounting for diet, smoking, physical activity, body mass index, blood pressure, cholesterol, blood glucose) among Hispanic, non-Hispanic Asian, or non-Hispanic Black adults compared with non-Hispanic White adults. RESULTS: Among 16 172 participants (representing 255 million US adults), 24% were Hispanic, 12% non-Hispanic Asian, 23% non-Hispanic Black, and 41% non-Hispanic White. Among men, mean (SE) CVH score was 7.45 (2.3) in Hispanic, 8.71 (2.2) in non-Hispanic Asian, 7.48 (2.4) in non-Hispanic Black, and 7.58 (2.3) in non-Hispanic White adults. In Kitagawa-Blinder-Oaxaca decomposition, education explained the largest component of CVH differences among men (if distribution of education were similar to non-Hispanic White participants, CVH score would be 0.36 [0.04] points higher in Hispanic, 0.24 [0.04] points lower in non-Hispanic Asian, and 0.23 [0.03] points higher in non-Hispanic Black participants; P<0.05). Among women, mean (SE) CVH score was 8.03 (2.4) in Hispanic, 9.34 (2.1) in non-Hispanic Asian, 7.43 (2.3) in non-Hispanic Black, and 8.00 (2.5) in non-Hispanic White adults. Education explained the largest component of CVH difference in non-Hispanic Black women (if distribution of education were similar to non-Hispanic White participants, CVH score would be 0.17 [0.03] points higher in non-Hispanic Black participants; P<0.05). Place of birth (born in the United States versus born outside the United States) explained the largest component of CVH difference in Hispanic and non-Hispanic Asian women (if distribution of place of birth were similar to non-Hispanic White participants, CVH score would be 0.36 [0.07] points lower and 0.49 [0.16] points lower, respectively; P<0.05). CONCLUSIONS: Education and place of birth confer the largest statistical contributions to the racial and ethnic differences in mean CVH score among US adults.

Recruiting and retaining nulliparous individuals with a family history of hypertensive disorders of pregnancy to participate in scientific research prior to pregnancy: The Sisterhood Study.

Introduction: Recruiting women with a family history (FH) of hypertensive disorders of pregnancy (HDP) to participate in research before pregnancy could offer insight into genetic and lifestyle factors that incur higher risk of cardiovascular disease during pregnancy and throughout the life course. Methods: The Sisterhood Study piloted low-touch, remote recruitment strategies that relied on women with a history of preeclampsia to share study information with family and friends. It aimed to enroll 150 women with a FH of HDP and 150 controls. Results: The study recruited 328 women (104 with a FH of HDP, 131 without a FH, and 93 with unknown FH) prior to pregnancy. The majority identified as non-Hispanic White (74.7%) and had > high school education (91.8%). Discussion: Although the population was enriched with nulliparous women with a FH of HDP, it was not sufficient to recruit a diverse cohort large enough to meet the study aim.

Association of Birth Year of Pregnant Individuals With Trends in Hypertensive Disorders of Pregnancy in the United States, 1995-2019.

Importance: Hypertensive disorders of pregnancy are leading causes of morbidity and mortality among pregnant individuals as well as newborns, with increasing incidence during the past decade. Understanding the individual associations of advancing age of pregnant individuals at delivery, more recent delivery year (period), and more recent birth year of pregnant individuals (cohort) with adverse trends in hypertensive disorders of pregnancy could help guide public health efforts to improve the health of pregnant individuals. Objective: To clarify the independent associations of delivery year and birth year of pregnant individuals, independent of age of pregnant individuals, with incident rates of hypertensive disorders of pregnancy. Design, Setting, and Participants: This serial cross-sectional study of 38 141 561 nulliparous individuals aged 15 to 44 years with a singleton, live birth used 1995-2019 natality data from the National Vital Statistics System. Exposures: Year of delivery (period) and birth year (cohort) of pregnant individuals. Main Outcomes and Measures: Rates of incident hypertensive disorders of pregnancy, defined as gestational hypertension, preeclampsia, or eclampsia, recorded on birth certificates. Generalized linear mixed models were used to calculate adjusted rate ratios (aRRs) comparing the incidence of hypertensive disorders of pregnancy in each delivery period (adjusted for age and cohort) and birth cohort (adjusted for age and period) with the baseline group as the reference for each. Analyses were additionally stratified by the self-reported racial and ethnic group of pregnant individuals. Results: Of 38 141 561 individuals, 20.2% were Hispanic, 0.8% were non-Hispanic American Indian or Alaska Native, 6.5% were non-Hispanic Asian or Pacific Islander, 13.9% were non-Hispanic Black, and 57.8% were non-Hispanic White. Among pregnant individuals who delivered in 2015 to 2019 compared with 1995 to 1999, the aRR for the incidence of hypertensive disorders of pregnancy was 1.59 (95% CI, 1.57-1.62), adjusted for age and cohort. Among pregnant individuals born in 1996 to 2004 compared with 1951 to 1959, the aRR for the incidence of hypertensive disorders of pregnancy was 2.61 (95% CI, 2.41-2.84), adjusted for age and period. The incidence was higher among self-identified non-Hispanic Black individuals in each birth cohort, with similar relative changes for period (aRR, 1.76 [95% CI, 1.70-1.81]) and cohort (aRR, 3.26 [95% CI, 2.72-3.91]) compared with non-Hispanic White individuals (period: aRR, 1.60 [95% CI, 1.57-1.63]; cohort: aRR, 2.53 [95% CI, 2.26-2.83]). Conclusions and Relevance: This cross-sectional study suggests that more recent birth cohorts of pregnant individuals have experienced a doubling of rates of hypertensive disorders of pregnancy, even after adjustment for age and delivery period. Substantial racial and ethnic disparities persisted across generations.