Pregnancy as a Window to Future Cardiovascular Health: Design and Implementation of the nuMoM2b Heart Health Study

Allostatic load in early pregnancy and sleep-disordered breathing

OBJECTIVES

To assess the association between allostatic load in early pregnancy and sleep-disordered breathing (SDB) during pregnancy.

METHODS

High allostatic load in the first trimester was defined as ≥ 4 of 12 biomarkers (systolic blood pressure, diastolic blood pressure, body mass index, cholesterol, low-density lipoprotein, high-density lipoprotein, high sensitivity C-reactive protein, triglycerides, insulin, glucose, creatinine, and albumin) in the unfavorable quartile. SDB was objectively measured using the Embletta-Gold device and operationalized as "SDB ever" in early (6-15 weeks) or mid-pregnancy (22-31 weeks); SDB at each time point was analyzed as secondary outcomes. Multivariable logistic regression was used to test the association between high allostatic load and SDB, adjusted for confounders. Moderation and sensitivity analyses were conducted to assess the role of allostatic load in racial disparities of SDB and obesity affected the relationship between allostatic load and SDB.

RESULTS

High allostatic load was present in 35.0% of the nuMoM2b cohort. The prevalence of SDB ever occurred among 8.3% during pregnancy. After adjustment, allostatic load remained significantly associated with SDB ever (aOR= 5.3; 3.6-7.9), in early-pregnancy (aOR= 7.0; 3.8-12.8), and in mid-pregnancy (aOR= 5.8; 3.7-9.1). The association between allostatic load and SDB was not significantly different for people with and without obesity. After excluding BMI from the allostatic load score, the association decreased in magnitude (aOR= 2.6; 1.8-3.9).

CONCLUSION

The association between allostatic load and SDB was independent of confounders including BMI. The complex and likely bidirectional relationship between chronic stress and SDB deserves further study in reducing SDB.

Gestational weight gain below recommendations and adverse maternal and child health outcomes for pregnancies with overweight or obesity: a United States cohort study

BACKGROUND

The current Institute of Medicine (IOM) pregnancy weight gain guidelines were developed using the best available evidence but were limited by substantial knowledge gaps. Some have raised concern that the guidelines for individuals affected by overweight or obesity are too high and contribute to short- and long-term complications for the mother and child.

OBJECTIVES

To determine the association between pregnancy weight gain below the lower limit of the current IOM recommendations and risk of 10 adverse maternal and child health outcomes among individuals with overweight and obesity.

METHODS

We used data from a prospective cohort study of United States nulliparae with prepregnancy overweight (n = 955) or obesity (n = 897) followed from the first trimester to 2-7 y postpartum. We used multivariable Poisson regression to relate pregnancy weight gain z-scores with a severity-weighted composite outcome consisting of ≥1 of 10 adverse outcomes (gestational diabetes, preeclampsia, unplanned cesarean delivery, maternal postpartum weight increase >10 kg, maternal postpartum metabolic syndrome, infant death, stillbirth, preterm birth, small-for-gestational age birth, and childhood obesity).

RESULTS

Pregnancy weight gain z-scores below, within, and above the IOM-recommended ranges occurred in 5%, 13%, and 80% of pregnancies with overweight and 17%, 13%, and 70% of pregnancies with obesity. There was a positive association between pregnancy weight gain z-scores and all adverse maternal outcomes, childhood obesity, and the composite outcome. Pregnancy weight gain z-scores below the lower limit of the recommended ranges (<6.8 kg for overweight, <5 kg for obesity) were not associated with the severity-weighted composite outcome. For example, compared with the lower limit, adjusted rate ratios (95% confidence interval) for z-scores of -2 standard deviations in pregnancies with overweight (equivalent to 3.6 kg at 40 wk) and obesity (-2.8 kg at 40 wk) were 0.99 (95% confidence interval [CI]: 0.91, 1.06) and 0.97 (95% CI: 0.87, 1.07).

CONCLUSIONS

These findings support arguments to decrease the lower limit of recommended weight gain ranges in these prepregnancy body mass index groups.

Low-dose aspirin, maternal cardiometabolic health, and offspring respiratory health 9 to 14 years after delivery: Findings from the EAGeR Follow-up Study

BACKGROUND

Accumulating evidence shows that peri-conceptional and in-utero exposures have lifetime health impacts for mothers and their offspring.

OBJECTIVES

We conducted a Follow-Up Study of the Effects of Aspirin in Gestation and Reproduction (EAGeR) trial with two objectives. First, we determined if women who enrolled at the Utah site (N = 1001) of the EAGeR trial (2007-2011, N = 1228) could successfully be contacted and agree to complete an online questionnaire on their reproductive, cardio-metabolic, and offspring respiratory health 9-14 years after original enrollment. Second, we evaluated if maternal exposure to low-dose aspirin (LDA) during pregnancy was associated with maternal cardio-metabolic health and offspring respiratory health.

METHODS

The original EAGeR study population included women, 18-40 years of age, who had 1-2 prior pregnancy losses, and who were trying to become pregnant. At follow-up (2020-2021), participants from the Utah cohort completed a 13-item online questionnaire on reproductive and cardio-metabolic health, and those who had a live birth during EAGeR additionally completed a 7-item questionnaire on the index child's respiratory health. Primary maternal outcomes included hypertension and hypercholesterolemia; primary offspring outcomes included wheezing and asthma.

RESULTS

Sixty-eight percent (n = 678) of participants enrolled in the follow-up study, with 10% and 15% reporting maternal hypertension and hypercholesterolemia, respectively; and 18% and 10% reporting offspring wheezing and asthma. We found no association between maternal LDA exposure and hypertension (risk difference [RD] -0.001, 95% confidence interval [CI] -0.05, 0.04) or hypercholesterolemia (RD -0.01, 95% CI -0.06, 0.05) at 9-14 years follow-up. Maternal LDA exposure was not associated with offspring wheezing (RD -0.002, 95% CI -0.08, 0.08) or asthma (RD 0.13, 95% CI 0.11, 0.37) at follow-up. Findings remained robust after considering potential confounding and selection bias.

CONCLUSIONS

We observed no association between LDA exposure during pregnancy and maternal cardiometabolic or offspring respiratory health.

Adverse Pregnancy Outcomes and Predicted 30-Year Risk of Maternal Cardiovascular Disease 2-7 Years After Delivery

OBJECTIVE

To determine whether adverse pregnancy outcomes are associated with a higher predicted 30-year risk of atherosclerotic cardiovascular disease (CVD; ie, coronary artery disease or stroke).

METHODS

This was a secondary analysis of the prospective Nulliparous Pregnancy Outcomes Study-Monitoring Mothers-to-Be Heart Health Study longitudinal cohort. The exposures were adverse pregnancy outcomes during the first pregnancy (ie, gestational diabetes mellitus [GDM], hypertensive disorder of pregnancy, preterm birth, and small- and large-for-gestational-age [SGA, LGA] birth weight) modeled individually and secondarily as the cumulative number of adverse pregnancy outcomes (ie, none, one, two or more). The outcome was the 30-year risk of atherosclerotic CVD predicted with the Framingham Risk Score assessed at 2-7 years after delivery. Risk was measured both continuously in increments of 1% and categorically, with high predicted risk defined as a predicted risk of atherosclerotic CVD of 10% or more. Linear regression and modified Poisson models were adjusted for baseline covariates.

RESULTS

Among 4,273 individuals who were assessed at a median of 3.1 years after delivery (interquartile range 2.5-3.7), the median predicted 30-year atherosclerotic CVD risk was 2.2% (interquartile range 1.4-3.4), and 1.8% had high predicted risk. Individuals with GDM (least mean square 5.93 vs 4.19, adjusted β=1.45, 95% CI, 1.14-1.75), hypertensive disorder of pregnancy (4.95 vs 4.22, adjusted β=0.49, 95% CI, 0.31-0.68), and preterm birth (4.81 vs 4.27, adjusted β=0.47, 95% CI, 0.24-0.70) were more likely to have a higher absolute risk of atherosclerotic CVD. Similarly, individuals with GDM (8.7% vs 1.4%, adjusted risk ratio [RR] 2.02, 95% CI, 1.14-3.59), hypertensive disorder of pregnancy (4.4% vs 1.4%, adjusted RR 1.91, 95% CI, 1.17-3.13), and preterm birth (5.0% vs 1.5%, adjusted RR 2.26, 95% CI, 1.30-3.93) were more likely to have a high predicted risk of atherosclerotic CVD. A greater number of adverse pregnancy outcomes within the first birth was associated with progressively greater risks, including per 1% atherosclerotic CVD risk (one adverse pregnancy outcome: 4.86 vs 4.09, adjusted β=0.59, 95% CI, 0.43-0.75; two or more adverse pregnancy outcomes: 5.51 vs 4.09, adjusted β=1.16, 95% CI, 0.82-1.50), and a high predicted risk of atherosclerotic CVD (one adverse pregnancy outcome: 3.8% vs 1.0%, adjusted RR 2.33, 95% CI, 1.40-3.88; two or more adverse pregnancy outcomes: 8.7 vs 1.0%, RR 3.43, 95% CI, 1.74-6.74). Small and large for gestational age were not consistently associated with a higher atherosclerotic CVD risk.

CONCLUSION

Individuals who experienced adverse pregnancy outcomes in their first birth were more likely to have a higher predicted 30-year risk of CVD measured at 2-7 years after delivery. The magnitude of risk was higher with a greater number of adverse pregnancy outcomes experienced.

Cardiovascular morbidity and mortality following hypertensive disorders of pregnancy

OBJECTIVES

To determine whether hypertensive disorders of pregnancy (HDP) are associated with maternal coronary artery disease (CAD) and other cardiovascular (CV) diseases within 10-20 years following delivery.

STUDY DESIGN

Retrospective cohort including all women who delivered ≥ 1 pregnancy ≥ 20 weeks' gestation within a single health system from 1998 to 2008. We excluded those with CV risk factors preceding first delivery or with no follow-up after delivery. The exposure of interest was any HDP, determined by ICD coding.

MAIN OUTCOME MEASURES

The primary outcome was a composite of ICD codes for CAD, peripheral vascular disease, and CV events (myocardial infarction, stroke, and death). Multivariable Cox proportional hazards estimated the association between exposure and outcomes. A nested cohort of women who underwent cardiac catheterization had a primary outcome of angiographic CAD, and multivariable logistic regression estimated the association between HDP and CAD.

RESULTS

Of 33,959 women included, 2,385 women had HDP. HDP was associated with the composite outcome (adjusted HR 1.50, 95 % CI 1.11, 2.03). There was a significant difference in event-free survival between groups (p = 0.003) with a median follow-up of 17.3 years. 592 women (1.7 %) underwent cardiac catheterization: 20 of 90 women with HDP had CAD (22.2 %) on angiography vs 49 of 502 without HDP (9.8 %, p < 0.001). HDP was associated with angiographic CAD (adjusted OR 2.08, 95 % CI 1.05, 4.11).

CONCLUSIONS

Women with HDP had twice the incidence of CAD on angiography compared to parous women without HDP. Obstetric history may inform the decision to perform cardiac catheterization in relatively young women.

Genetic Associations with Placental Proteins in Maternal Serum Identify Biomarkers for Hypertension in Pregnancy

Background

Preeclampsia is a complex syndrome that accounts for considerable maternal and perinatal morbidity and mortality. Despite its prevalence, no effective disease-modifying therapies are available. Maternal serum placenta-derived proteins have been in longstanding use as markers of risk for aneuploidy and placental dysfunction, but whether they have a causal contribution to preeclampsia is unknown.

Objective

We aimed to investigate the genetic regulation of serum placental proteins in early pregnancy and their potential causal links with preeclampsia and gestational hypertension.

Study design

This study used a nested case-control design with nulliparous women enrolled in the nuMoM2b study from eight clinical sites across the United States between 2010 and 2013. The first- and second-trimester serum samples were collected, and nine proteins were measured, including vascular endothelial growth factor (VEGF), placental growth factor, endoglin, soluble fms-like tyrosine kinase-1 (sFlt-1), a disintegrin and metalloproteinase domain-containing protein 12 (ADAM-12), pregnancy-associated plasma protein A, free beta-human chorionic gonadotropin, inhibin A, and alpha-fetoprotein. This study used genome-wide association studies to discern genetic influences on these protein levels, treating proteins as outcomes. Furthermore, Mendelian randomization was used to evaluate the causal effects of these proteins on preeclampsia and gestational hypertension, and their further causal relationship with long-term hypertension, treating proteins as exposures.

Results

A total of 2,352 participants were analyzed. We discovered significant associations between the pregnancy zone protein locus and concentrations of ADAM-12 (rs6487735, P= 3.03×10 -22 ), as well as between the vascular endothelial growth factor A locus and concentrations of both VEGF (rs6921438, P= 7.94×10 -30 ) and sFlt-1 (rs4349809, P= 2.89×10 -12 ). Our Mendelian randomization analyses suggested a potential causal association between first-trimester ADAM-12 levels and gestational hypertension (odds ratio=0.78, P= 8.6×10 -4 ). We also found evidence for a potential causal effect of preeclampsia (odds ratio=1.75, P =8.3×10 -3 ) and gestational hypertension (odds ratio=1.84, P =4.7×10 -3 ) during the index pregnancy on the onset of hypertension 2-7 years later. The additional mediation analysis indicated that the impact of ADAM-12 on postpartum hypertension could be explained in part by its indirect effect through gestational hypertension (mediated effect=-0.15, P= 0.03).

Conclusions

Our study discovered significant genetic associations with placental proteins ADAM-12, VEGF, and sFlt-1, offering insights into their regulation during pregnancy. Mendelian randomization analyses demonstrated evidence of potential causal relationships between the serum levels of placental proteins, particularly ADAM-12, and gestational hypertension, potentially informing future prevention and treatment investigations.

Socioeconomic disadvantage in pregnancy and postpartum risk of cardiovascular disease

BACKGROUND

Pregnancy is an educable and actionable life stage to address social determinants of health (SDOH) and lifelong cardiovascular disease (CVD) prevention. However, the link between a risk score that combines multiple neighborhood-level social determinants in pregnancy and the risk of long-term CVD remains to be evaluated.

OBJECTIVE

To examine whether neighborhood-level socioeconomic disadvantage measured by the Area Deprivation Index (ADI) in early pregnancy is associated with a higher 30-year predicted risk of CVD postpartum, as measured by the Framingham Risk Score.

STUDY DESIGN

An analysis of data from the prospective Nulliparous Pregnancy Outcomes Study-Monitoring Mothers-to-Be Heart Health Study longitudinal cohort. Participant home addresses during early pregnancy were geocoded at the Census-block level. The exposure was neighborhood-level socioeconomic disadvantage using the 2015 ADI by tertile (least deprived [T1], reference; most deprived [T3]) measured in the first trimester. Outcomes were the predicted 30-year risks of atherosclerotic cardiovascular disease (ASCVD, composite of fatal and nonfatal coronary heart disease and stroke) and total CVD (composite of ASCVD plus coronary insufficiency, angina pectoris, transient ischemic attack, intermittent claudication, and heart failure) using the Framingham Risk Score measured 2 to 7 years after delivery. These outcomes were assessed as continuous measures of absolute estimated risk in increments of 1%, and, secondarily, as categorical measures with high-risk defined as an estimated probability of CVD ≥10%. Multivariable linear regression and modified Poisson regression models adjusted for baseline age and individual-level social determinants, including health insurance, educational attainment, and household poverty.

RESULTS

Among 4309 nulliparous individuals at baseline, the median age was 27 years (interquartile range [IQR]: 23-31) and the median ADI was 43 (IQR: 22-74). At 2 to 7 years postpartum (median: 3.1 years, IQR: 2.5, 3.7), the median 30-year risk of ASCVD was 2.3% (IQR: 1.5, 3.5) and of total CVD was 5.5% (IQR: 3.7, 7.9); 2.2% and 14.3% of individuals had predicted 30-year risk ≥10%, respectively. Individuals living in the highest ADI tertile had a higher predicted risk of 30-year ASCVD % (adjusted ß: 0.41; 95% confidence interval [CI]: 0.19, 0.63) compared with those in the lowest tertile; and those living in the top 2 ADI tertiles had higher absolute risks of 30-year total CVD % (T2: adj. ß: 0.37; 95% CI: 0.03, 0.72; T3: adj. ß: 0.74; 95% CI: 0.36, 1.13). Similarly, individuals living in neighborhoods in the highest ADI tertile were more likely to have a high 30-year predicted risk of ASCVD (adjusted risk ratio [aRR]: 2.21; 95% CI: 1.21, 4.02) and total CVD ≥10% (aRR: 1.35; 95% CI: 1.08, 1.69).

CONCLUSION

Neighborhood-level socioeconomic disadvantage in early pregnancy was associated with a higher estimated long-term risk of CVD postpartum. Incorporating aggregated SDOH into existing clinical workflows and future research in pregnancy could reduce disparities in maternal cardiovascular health across the lifespan, and requires further study.

Genetic polymorphisms associated with adverse pregnancy outcomes in nulliparas

Adverse pregnancy outcomes (APOs) affect a large proportion of pregnancies and represent an important cause of morbidity and mortality worldwide. Yet the pathophysiology of APOs is poorly understood, limiting our ability to prevent and treat these conditions. To search for genetic markers of maternal risk for four APOs, we performed multi-ancestry genome-wide association studies (GWAS) for pregnancy loss, gestational length, gestational diabetes, and preeclampsia. We clustered participants by their genetic ancestry and focused our analyses on three sub-cohorts with the largest sample sizes: European, African, and Admixed American. Association tests were carried out separately for each sub-cohort and then meta-analyzed together. Two novel loci were significantly associated with an increased risk of pregnancy loss: a cluster of SNPs located downstream of the TRMU gene (top SNP: rs142795512), and the SNP rs62021480 near RGMA. In the GWAS of gestational length we identified two new variants, rs2550487 and rs58548906 near WFDC1 and AC005052.1, respectively. Lastly, three new loci were significantly associated with gestational diabetes (top SNPs: rs72956265, rs10890563, rs79596863), located on or near ZBTB20, GUCY1A2, and RPL7P20, respectively. Fourteen loci previously correlated with preterm birth, gestational diabetes, and preeclampsia were found to be associated with these outcomes as well.

Prediction of metabolic syndrome following a first pregnancy

BACKGROUND

The prevalence of metabolic syndrome is rapidly increasing in the United States. We hypothesized that prediction models using data obtained during pregnancy can accurately predict the future development of metabolic syndrome.

OBJECTIVE

This study aimed to develop machine learning models to predict the development of metabolic syndrome using factors ascertained in nulliparous pregnant individuals.

STUDY DESIGN

This was a secondary analysis of a prospective cohort study (Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be Heart Health Study [nuMoM2b-HHS]). Data were collected from October 2010 to October 2020, and analyzed from July 2023 to October 2023. Participants had in-person visits 2 to 7 years after their first delivery. The primary outcome was metabolic syndrome, defined by the National Cholesterol Education Program Adult Treatment Panel III criteria, which was measured within 2 to 7 years after delivery. A total of 127 variables that were obtained during pregnancy were evaluated. The data set was randomly split into a training set (70%) and a test set (30%). We developed a random forest model and a lasso regression model using variables obtained during pregnancy. We compared the area under the receiver operating characteristic curve for both models. Using the model with the better area under the receiver operating characteristic curve, we developed models that included fewer variables based on SHAP (SHapley Additive exPlanations) values and compared them with the original model. The final model chosen would have fewer variables and noninferior areas under the receiver operating characteristic curve.

RESULTS

A total of 4225 individuals met the inclusion criteria; the mean (standard deviation) age was 27.0 (5.6) years. Of these, 754 (17.8%) developed metabolic syndrome. The area under the receiver operating characteristic curve of the random forest model was 0.878 (95% confidence interval, 0.846-0.909), which was higher than the 0.850 of the lasso model (95% confidence interval, 0.811-0.888; P<.001). Therefore, random forest models using fewer variables were developed. The random forest model with the top 3 variables (high-density lipoprotein, insulin, and high-sensitivity C-reactive protein) was chosen as the final model because it had the area under the receiver operating characteristic curve of 0.867 (95% confidence interval, 0.839-0.895), which was not inferior to the original model (P=.08). The area under the receiver operating characteristic curve of the final model in the test set was 0.847 (95% confidence interval, 0.821-0.873). An online application of the final model was developed (https://kawakita.shinyapps.io/metabolic/).

CONCLUSION

We developed a model that can accurately predict the development of metabolic syndrome in 2 to 7 years after delivery.

Association between pregnancy-related complications and development of type 2 diabetes and hypertension in women: an umbrella review

BACKGROUND

Despite many systematic reviews and meta-analyses examining the associations of pregnancy complications with risk of type 2 diabetes mellitus (T2DM) and hypertension, previous umbrella reviews have only examined a single pregnancy complication. Here we have synthesised evidence from systematic reviews and meta-analyses on the associations of a wide range of pregnancy-related complications with risk of developing T2DM and hypertension.

METHODS

Medline, Embase and Cochrane Database of Systematic Reviews were searched from inception until 26 September 2022 for systematic reviews and meta-analysis examining the association between pregnancy complications and risk of T2DM and hypertension. Screening of articles, data extraction and quality appraisal (AMSTAR2) were conducted independently by two reviewers using Covidence software. Data were extracted for studies that examined the risk of T2DM and hypertension in pregnant women with the pregnancy complication compared to pregnant women without the pregnancy complication. Summary estimates of each review were presented using tables, forest plots and narrative synthesis and reported following Preferred Reporting Items for Overviews of Reviews (PRIOR) guidelines.

RESULTS

Ten systematic reviews were included. Two pregnancy complications were identified. Gestational diabetes mellitus (GDM): One review showed GDM was associated with a 10-fold higher risk of T2DM at least 1 year after pregnancy (relative risk (RR) 9.51 (95% confidence interval (CI) 7.14 to 12.67) and although the association differed by ethnicity (white: RR 16.28 (95% CI 15.01 to 17.66), non-white: RR 10.38 (95% CI 4.61 to 23.39), mixed: RR 8.31 (95% CI 5.44 to 12.69)), the between subgroups difference were not statistically significant at 5% significance level. Another review showed GDM was associated with higher mean blood pressure at least 3 months postpartum (mean difference in systolic blood pressure: 2.57 (95% CI 1.74 to 3.40) mmHg and mean difference in diastolic blood pressure: 1.89 (95% CI 1.32 to 2.46) mmHg). Hypertensive disorders of pregnancy (HDP): Three reviews showed women with a history of HDP were 3 to 6 times more likely to develop hypertension at least 6 weeks after pregnancy compared to women without HDP (meta-analysis with largest number of studies: odds ratio (OR) 4.33 (3.51 to 5.33)) and one review reported a higher rate of T2DM after HDP (hazard ratio (HR) 2.24 (1.95 to 2.58)) at least a year after pregnancy. One of the three reviews and five other reviews reported women with a history of preeclampsia were 3 to 7 times more likely to develop hypertension at least 6 weeks postpartum (meta-analysis with the largest number of studies: OR 3.90 (3.16 to 4.82) with one of these reviews reporting the association was greatest in women from Asia (Asia: OR 7.54 (95% CI 2.49 to 22.81), Europe: OR 2.19 (95% CI 0.30 to 16.02), North and South America: OR 3.32 (95% CI 1.26 to 8.74)).

CONCLUSIONS

GDM and HDP are associated with a greater risk of developing T2DM and hypertension. Common confounders adjusted for across the included studies in the reviews were maternal age, body mass index (BMI), socioeconomic status, smoking status, pre-pregnancy and current BMI, parity, family history of T2DM or cardiovascular disease, ethnicity, and time of delivery. Further research is needed to evaluate the value of embedding these pregnancy complications as part of assessment for future risk of T2DM and chronic hypertension.

Do current pregnancy weight gain guidelines balance risks of adverse maternal and child health in a United States cohort?

BACKGROUND

The Institute of Medicine pregnancy weight gain guidelines were developed without evidence linking high weight gain to maternal cardiometabolic disease and child obesity. The upper limit of current recommendations may be too high for the health of the pregnant individual and child.

OBJECTIVES

The aim of this study was to identify the range of pregnancy weight gain for pregnancies within a normal body mass index (BMI) range that balances the risks of high and low weight gain by simultaneously considering 10 different health conditions.

METHODS

We used data from an United States prospective cohort study of nulliparae followed until 2 to 7 y postpartum (N = 2344 participants with a normal BMI). Pregnancy weight gain z-score was the main exposure. The outcome was a composite consisting of the occurrence of ≥1 of 10 adverse health conditions that were weighted for their seriousness. We used multivariable Poisson regression to relate weight gain z-scores with the weighted composite outcome.

RESULTS

The lowest risk of the composite outcome was at a pregnancy weight gain z-score of -0.6 SD (standard deviation) (equivalent to 13.1 kg at 40 wk). The weight gain ranges associated with no more than 5%, 10%, and 20% increase in risks were -1.0 to -0.2 SD (11.2-15.3 kg), -1.4 to 0 SD (9.4-16.4 kg), and -2.0 to 0.4 SD (7.0-18.9 kg). When we used a lower threshold to define postpartum weight increase in the composite outcome (>5 kg compared with >10 kg), the ranges were 1.6 to -0.7 SD (8.9-12.6 kg), -2.2 to -0.3 SD (6.3-14.7 kg), and ≤0.2 SD (≤17.6 kg). Compared with the ranges of the current weight gain guidelines (-0.9 to -0.1 SD, 11.5-16 kg), the lower limits from our data tended to be lower while upper limits were similar or lower.

CONCLUSIONS

If replicated, our results suggest that policy makers should revisit the recommended pregnancy weight gain range for individuals within a normal BMI range.

Periconceptional Dietary Patterns and Adverse Pregnancy and Birth Outcomes

BACKGROUND

The periconceptional period is a critical window for the origins of adverse pregnancy and birth outcomes, yet little is known about the dietary patterns that promote perinatal health.

OBJECTIVE

We used machine learning methods to determine the effect of periconceptional dietary patterns on risk of preeclampsia, gestational diabetes, preterm birth, small-for-gestational-age (SGA) birth, and a composite of these outcomes.

METHODS

We used data from 8259 participants in the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (8 US medical centers, 2010‒2013). Usual daily periconceptional intake of 82 food groups was estimated from a food frequency questionnaire. We used k-means clustering with a Euclidean distance metric to identify dietary patterns. We estimated the effect of dietary patterns on each perinatal outcome using targeted maximum likelihood estimation and an ensemble of machine learning algorithms, adjusting for confounders including health behaviors and psychological, neighborhood, and sociodemographic factors.

RESULTS

The 4 dietary patterns that emerged from our data were identified as "Sandwiches and snacks" (34% of the sample); "High fat, sugar, and sodium" (29%); "Beverages, refined grains, and mixed dishes" (21%); and "High fruits, vegetables, whole grains, and plant proteins" (16%). One-quarter of pregnancies had preeclampsia (8% incidence), gestational diabetes (5%), preterm birth (8%), or SGA birth (8%). Compared with the "High fat, sugar, and sodium" pattern, there were 3.3 to 4.3 fewer cases of the composite adverse outcome per 100 pregnancies among participants following the "Beverages, refined grains and mixed dishes" pattern (risk difference -0.043; 95% confidence interval -0.078, -0.009), "High fruits, vegetables, whole grains and plant proteins" pattern (-0.041; 95% confidence interval -0.078, -0.004), and "Sandwiches and snacks" pattern (-0.033; 95% confidence interval -0.065, -0.002).

CONCLUSIONS

Our results highlight that there are a variety of periconceptional dietary patterns that are associated with perinatal health and reinforce the negative health implications of diets high in fat, sugars, and sodium.

Long-term maternal mortality risk following spontaneous preterm birth: A retrospective cohort study

OBJECTIVE

To determine whether women with spontaneous preterm birth (PTB) have increased risks for long-term mortality.

DESIGN

Retrospective cohort.

SETTING

Births in Utah between 1939 and 1977.

POPULATION

We included women with a singleton live birth ≥20 weeks who survived at least 1 year following delivery. We excluded those who had never lived in Utah, had improbable birthweight/gestational age combinations, underwent induction (except for preterm membrane rupture) or had another diagnosis likely to cause PTB.

METHODS

Exposed women had ≥1 spontaneous PTB between 20+0  weeks and 37+0  weeks. Women with >1 spontaneous PTB were included only once. Unexposed women had all deliveries at or beyond 38+0  weeks. Exposed women were matched to unexposed women by birth year, infant sex, maternal age group and infant birth order. Included women were followed up to 39 years after index delivery.

MAIN OUTCOME MEASURES

Overall and cause-specific mortality risks were compared using Cox regression.

RESULTS

We included 29 048 exposed and 57 992 matched unexposed women. There were 3551 deaths among exposed (12.2%) and 6013 deaths among unexposed women (10.4%). Spontaneous PTB was associated with all-cause mortality (adjusted hazard ratio [aHR] 1.26, 95% confidence interval [CI] 1.21-1.31), death from neoplasms (aHR 1.10, 95% CI 1.02-1.18), circulatory disease (aHR 1.35, 95% CI 1.25-1.46), respiratory disease (aHR 1.73, 95% CI 1.46-2.06), digestive disease (aHR 1.33, 95% CI 1.12-1.58), genito-urinary disease (aHR 1.60, 95% CI 1.15-2.23) and external causes (aHR 1.39, 95% CI 1.22-1.58).

CONCLUSIONS

Spontaneous PTB is associated with modestly increased risks for all-cause and some cause-specific mortality.

Body Mass Index, Adverse Pregnancy Outcomes, and Cardiovascular Disease Risk

BACKGROUND

Obesity is a well-established risk factor for both adverse pregnancy outcomes (APOs) and cardiovascular disease (CVD). However, it is not known whether APOs are mediators or markers of the obesity-CVD relationship. This study examined the association between body mass index, APOs, and postpartum CVD risk factors.

METHODS

The sample included adults from the nuMoM2b (Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-To-Be) Heart Health Study who were enrolled in their first trimester (6 weeks-13 weeks 6 days gestation) from 8 United States sites. Participants had a follow-up visit at 3.7 years postpartum. APOs, which included hypertensive disorders of pregnancy, preterm birth, small-for-gestational-age birth, and gestational diabetes, were centrally adjudicated. Mediation analyses estimated the association between early pregnancy body mass index and postpartum CVD risk factors (hypertension, hyperlipidemia, and diabetes) and the proportion mediated by each APO adjusted for demographics and baseline health behaviors, psychosocial stressors, and CVD risk factor levels.

RESULTS

Among 4216 participants enrolled, mean±SD maternal age was 27±6 years. Early pregnancy prevalence of overweight was 25%, and obesity was 22%. Hypertensive disorders of pregnancy occurred in 15%, preterm birth in 8%, small-for-gestational-age birth in 11%, and gestational diabetes in 4%. Early pregnancy obesity, compared with normal body mass index, was associated with significantly higher incidence of postpartum hypertension (adjusted odds ratio, 1.14 [95% CI, 1.10-1.18]), hyperlipidemia (1.11 [95% CI, 1.08-1.14]), and diabetes (1.03 [95% CI, 1.01-1.04]) even after adjustment for baseline CVD risk factor levels. APOs were associated with higher incidence of postpartum hypertension (1.97 [95% CI, 1.61-2.40]) and hyperlipidemia (1.31 [95% CI, 1.03-1.67]). Hypertensive disorders of pregnancy mediated a small proportion of the association between obesity and incident hypertension (13% [11%-15%]) and did not mediate associations with incident hyperlipidemia or diabetes. There was no significant mediation by preterm birth or small-for-gestational-age birth.

CONCLUSIONS

There was heterogeneity across APO subtypes in their association with postpartum CVD risk factors and mediation of the association between early pregnancy obesity and postpartum CVD risk factors. However, only a small or nonsignificant proportion of the association between obesity and CVD risk factors was mediated by any of the APOs, suggesting APOs are a marker of prepregnancy CVD risk and not a predominant cause of postpartum CVD risk.

Searching and visualizing genetic associations of pregnancy traits by using GnuMoM2b

Adverse pregnancy outcomes (APOs) are major risk factors for women's health during pregnancy and even in the years after pregnancy. Due to the heterogeneity of APOs, only few genetic associations have been identified. In this report, we conducted genome-wide association studies (GWASs) of 479 traits that are possibly related to APOs using a large and racially diverse study, Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (nuMoM2b). To display extensive results, we developed a web-based tool GnuMoM2b (https://gnumom2b.cumcobgyn.org/) for searching, visualizing, and sharing results from a GWAS of 479 pregnancy traits as well as phenome-wide association studies of more than 17 million single nucleotide polymorphisms. The genetic results from 3 ancestries (Europeans, Africans, and Admixed Americans) and meta-analyses are populated in GnuMoM2b. In conclusion, GnuMoM2b is a valuable resource for extraction of pregnancy-related genetic results and shows the potential to facilitate meaningful discoveries.

Adverse Pregnancy Outcomes and Future Metabolic Syndrome

Background: Metabolic syndrome (MetS) is associated with a history of gestational diabetes (GDM), hypertensive disorders of pregnancy (HDP), and preterm birth (PTB), but it is unclear whether this association is due to the pregnancy complication(s) or prepregnancy/early pregnancy confounders. The study examines the association of GDM, HDP, and PTB with MetS 2-7 years later, independent of early pregnancy factors. Materials and Methods: Large, diverse cohort of nulliparous pregnant people with singleton gestations enrolled during their first trimester and who attended a follow-up study visit 2-7 years after delivery. The longitudinal cohort was recruited from eight medical centers across the United States. Using standardized protocols, anthropometry, biospecimens, and surveys were collected at study visits and pregnancy outcomes were abstracted from medical records. We estimated the relative risk of prevalent MetS at the follow-up study visit for participants with GDM, HDP, or PTB (vs. no complications), adjusting for early pregnancy age, body mass index, self-reported race/ethnicity, insurance type, and smoking status. Results: Of 4,402 participants, 738 (16.8%) had MetS at follow-up: 13.1% (441/3,365) among those with no complications, and 27.9% (290/1,002) among those with complications. MetS occurred in 39.0% of GDM (73/187, adjusted relative risk [aRR] = 1.75; 95% confidence interval [CI] 1.42-2.16); 29.2% of HDP (176/603, aRR = 1.49; 95% CI 1.27-1.75); and 29.7% of PTB (113/380, aRR = 1.78; 95% CI 1.49-2.12). Those who had both HDP and PTB (n = 113) had an aRR = 1.95 (95% CI 1.50-2.54). Conclusions: People whose pregnancies were complicated by GDM, HDP, or PTB are at a higher risk of MetS within 2-7 years after delivery, independent of early pregnancy risk factors. The highest MetS risk follows pregnancies complicated by both HDP and PTB.

The association between multidimensional sleep health and gestational weight gain

BACKGROUND

Although poor sleep health is associated with weight gain and obesity in the non-pregnant population, research on the impact of sleep health on weight change among pregnant people using a multidimensional sleep health framework is needed.

OBJECTIVES

This secondary data analysis of the Nulliparous Pregnancy Outcome Study: Monitoring Mothers-to-be Sleep Duration and Continuity Study (n = 745) examined associations between mid-pregnancy sleep health indicators, multidimensional sleep health and gestational weight gain (GWG).

METHODS

Sleep domains (i.e. regularity, nap duration, timing, efficiency and duration) were assessed via actigraphy between 16 and 21 weeks of gestation. We defined 'healthy' sleep in each domain with empirical thresholds. Multidimensional sleep health was based on sleep profiles derived from latent class analysis and composite score defined as the sum of healthy sleep domains. Total GWG, the difference between self-reported pre-pregnancy weight and the last measured weight before delivery, was converted to z-scores using gestational age- and BMI-specific charts. GWG was defined as low (<-1 SD), moderate (-1 or +1 SD) and high (>+1 SD).

RESULTS

Nearly 50% of the participants had a healthy sleep profile (i.e. healthy sleep in most domains), whereas others had a sleep profile defined as having varying degrees of unhealthy sleep in each domain. The individual sleep domains were associated with a 20%-30% lower risk of low or high GWG. Each additional healthy sleep indicator was associated with a 10% lower risk of low (vs. moderate), but not high, GWG. Participants with late timing, long duration and low efficiency (vs. healthy) profiles had the strongest risk of low GWG (relative risk 1.5, 95% confidence interval 0.9, 2.4). Probabilistic bias analysis suggested that most associations between individual sleep health indicators, sleep health profiles and GWG were biased towards the null.

CONCLUSIONS

Future research should determine whether sleep health is an intervention target for healthy GWG.

Serum Cotinine and Adverse Cardiovascular Outcomes: A Cross-sectional Secondary Analysis of the nuMoM2b Heart Health Study

OBJECTIVE

We aimed to (1) compare serum cotinine with self-report for ascertaining smoking status among reproductive-aged women; (2) estimate the relative odds of adverse cardiovascular (CV) outcomes among women by smoking status; (3) assess whether the association between adverse pregnancy outcomes (APOs) and CV outcomes varies by smoking status.

STUDY DESIGN

We conducted a cross-sectional study of the nuMoM2b Heart Health Study. Women attended a study visit 2 to 7 years after their first pregnancy. The exposure was smoking status, determined by self-report and by serum cotinine. Outcomes included incident chronic hypertension (HTN), metabolic syndrome (MetS), and dyslipidemia. Multivariable logistic regression estimated odds ratios (ORs) for each outcome by smoking status.

RESULTS

Of 4,392 women with serum cotinine measured, 3,610 were categorized as nonsmokers, 62 as secondhand smoke exposure, and 720 as smokers. Of 3,144 women who denied tobacco smoke exposure, serum cotinine was consistent with secondhand smoke exposure in 48 (1.5%) and current smoking in 131 (4.2%) After adjustment for APOs, smoking defined by serum cotinine was associated with MetS (adjusted OR [aOR] = 1.52, 95% confidence interval [CI]: 1.21, 1.91) and dyslipidemia (aOR = 1.28, 95% CI: 1.01, 1.62). When stratified by nicotine exposure, nonsmokers with an APO in their index pregnancy had higher odds of stage 1 (aOR = 1.64, 95% CI: 1.32, 2.03) and stage 2 HTN (aOR = 2.92, 95% CI: 2.17, 3.93), MetS (aOR = 1.76, 95% CI: 1.42, 2.18), and dyslipidemia (aOR = 1.55, 95% CI: 1.25, 1.91) relative to women with no APO. Results were similar when smoking exposure was defined by self-report.

CONCLUSION

Whether determined by serum cotinine or self-report, smoking is associated with subsequent CV outcomes in reproductive-aged women. APOs are also independently associated with CV outcomes in women.

KEY POINTS

· Cotinine was detected in 5.7% of reported nonsmokers.. · Smoking and APOs were independently associated with CV health.. · Smoking was associated with MetS and dyslipidemia..

Searching and visualizing genetic associations of pregnancy traits by using GnuMoM2b

Adverse pregnancy outcomes (APOs) are major risk factors for women's health during pregnancy and even in the years after pregnancy. Due to the heterogeneity of APOs, only few genetic associations have been identified. In this report, we conducted genome-wide association studies (GWAS) of 479 traits that are possibly related to APOs using a large and racially diverse study, Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (nuMoM2b). To display the extensive results, we developed a web-based tool GnuMoM2b ( https://gnumom2b.cumcobgyn.org/ ) for searching, visualizing, and sharing results from GWAS of 479 pregnancy traits as well as phenome-wide association studies (PheWAS) of more than 17 million single nucleotide polymorphisms (SNPs). The genetic results from three ancestries (Europeans, Africans, and Admixed Americans) and meta-analyses are populated in GnuMoM2b. In conclusion, GnuMoM2b is a valuable resource for extraction of pregnancy-related genetic results and shows the potential to facilitate meaningful discoveries.

The association between multidimensional sleep health and gestational weight gain: nuMoM2b Sleep Duration and Continuity Study

Background

Although poor sleep health is associated with weight gain and obesity in the non-pregnant population, research on the impact of sleep health on weight change among pregnant people using a multidimensional sleep-health framework is needed. This study examined associations among mid-pregnancy sleep health indicators, multidimensional sleep health, and gestational weight gain (GWG).

Methods

We conducted a secondary data analysis of the Nulliparous Pregnancy Outcome Study: Monitoring Mothers-to-be Sleep Duration and Continuity Study (n=745). Indicators of individual sleep domains (i.e., regularity, nap duration, timing, efficiency, and duration) were assessed via actigraphy between 16 and 21 weeks of gestation. We defined "healthy" sleep in each domain based on empirical thresholds. Multidimensional sleep health was based on sleep profiles derived from latent class analysis. Total GWG, the difference between self-reported pre-pregnancy weight and the last measured weight before delivery, was converted to z-scores using gestational age- and BMI-specific charts. GWG was defined as low (<-1 SD), moderate (-1 or +1 SD), and high (>+1 SD).

Results

Nearly 50% of the participants had a healthy sleep profile (i.e., healthy sleep in most domains), whereas others had a sleep profile defined as having varying degrees of poor health in each domain. While indicators of individual sleep domains were not associated with GWG, multidimensional sleep health was related to low and high GWG. Participants with a sleep profile characterized as having low efficiency, late timing, and long sleep duration (vs. healthy sleep profile) had a higher risk (RR 1.7; 95% CI 1.0, 3.1) of low GWG a lower risk of high GWG (RR 0.5 95% CI 0.2, 1.1) (vs. moderate GWG).

Conclusions

Multidimensional sleep health was more strongly associated with GWG than individual sleep domains. Future research should determine whether sleep health is a valuable intervention target for optimizing GWG.

Synopsis

Study question: What is the association between mid-pregnancy multidimensional sleep health and gestational weight gain?What's already known?: Sleep is associated with weight and weight gain outside of pregnancyWhat does this study add?: We identified patterns of sleep behaviors associated with an increased risk of low gestational weight gain.

Protocol for development and validation of postpartum cardiovascular disease (CVD) risk prediction model incorporating reproductive and pregnancy-related candidate predictors

BACKGROUND

Cardiovascular disease (CVD) is a leading cause of death among women. CVD is associated with reduced quality of life, significant treatment and management costs, and lost productivity. Estimating the risk of CVD would help patients at a higher risk of CVD to initiate preventive measures to reduce risk of disease. The Framingham risk score and the QRISK® score are two risk prediction models used to evaluate future CVD risk in the UK. Although the algorithms perform well in the general population, they do not take into account pregnancy complications, which are well known risk factors for CVD in women and have been highlighted in a recent umbrella review. We plan to develop a robust CVD risk prediction model to assess the additional value of pregnancy risk factors in risk prediction of CVD in women postpartum.

METHODS

Using candidate predictors from QRISK®-3, the umbrella review identified from literature and from discussions with clinical experts and patient research partners, we will use time-to-event Cox proportional hazards models to develop and validate a 10-year risk prediction model for CVD postpartum using Clinical Practice Research Datalink (CPRD) primary care database for development and internal validation of the algorithm and the Secure Anonymised Information Linkage (SAIL) databank for external validation. We will then assess the value of additional candidate predictors to the QRISK®-3 in our internal and external validations.

DISCUSSION

The developed risk prediction model will incorporate pregnancy-related factors which have been shown to be associated with future risk of CVD but have not been taken into account in current risk prediction models. Our study will therefore highlight the importance of incorporating pregnancy-related risk factors into risk prediction modeling for CVD postpartum.

Allostatic Load and Adverse Pregnancy Outcomes

OBJECTIVE

To assess the association between allostatic load, as an estimate of chronic stress, and adverse pregnancy outcomes.

METHODS

This was a secondary analysis of nuMoM2b (Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be), a prospective observational cohort study. Our primary exposure was dichotomous high allostatic load in the first trimester, defined as 4 or more of 12 biomarkers in the "worst" quartile. The primary outcome was a composite adverse pregnancy outcome: hypertensive disorders of pregnancy (HDP), preterm birth, small for gestational age (SGA), and stillbirth. Secondary outcomes included components of the composite. Multivariable logistic regression was used to test the association between high allostatic load and adverse pregnancy outcomes, adjusted for potential confounders. Mediation and moderation analyses were conducted to assess the role of allostatic load along the causal pathway between racial disparities and adverse pregnancy outcomes.

RESULTS

Among 4,266 individuals, 34.7% had a high allostatic load. Composite adverse pregnancy outcome occurred in 1,171 (27.5%): 14.0% HDP, 8.6% preterm birth (48.0% spontaneous and 52.2% indicated), 11.0% SGA, and 0.3% stillbirth. After adjustment for maternal age, gravidity, smoking, bleeding in the first trimester, and health insurance, high allostatic load was significantly associated with a composite adverse pregnancy outcome (adjusted odds ratio [aOR] 1.5, 95% CI 1.3, 1.7) and HDP (aOR 2.5, 95% CI 2.0-2.9), but not preterm birth or SGA. High allostatic load partially mediated the association between self-reported race and adverse pregnancy outcomes. The association between allostatic load and HDP differed by self-reported race, but not for a composite adverse pregnancy outcome, preterm birth, or SGA.

CONCLUSION

High allostatic load in the first trimester is associated with adverse pregnancy outcomes, particularly HDP. Allostatic load was a partial mediator between race and adverse pregnancy outcomes. The association between allostatic load and HDP differed by self-reported race.

Factors associated with duration of breastfeeding in women giving birth for the first time

Objective

To examine maternal, psychosocial, and pregnancy factors associated with breastfeeding for at least 6 months in those giving birth for the first time.

Methods

We performed a planned secondary analysis of an observational cohort study of 5249 women giving birth for the first time. Women were contacted at least 6 months after delivery and provided information regarding breastfeeding initiation, duration, and exclusivity. Maternal demographics, psychosocial measures, and delivery methods were compared by breastfeeding groups.

Results

4712 (89.8%) of the women breastfed at some point, with 2739 (58.2%) breastfeeding for at least 6 months. Of those who breastfed, 1161 (24.7% of the entire cohort), breastfed exclusively for at least 6 months. In the multivariable model among those who ever breastfed, not smoking in the month prior to delivery (adjusted odds ratio [aOR] 2.04, 95%CI 1.19–3.45), having a Master’s degree of higher (aOR 1.89, 95%CI 1.51–2.36), having a planned pregnancy (aOR 1.48, 95%CI 1.27–1.73), older age (aOR 1.02, 95% CI, 1.01–1.04), lower BMI (aOR 0.96 95% CI 0.95–0.97), and having less anxiety measured during pregnancy (aOR 0.990, 95%CI 0.983–0.998) were associated with breastfeeding for at least 6 months. Compared to non-Hispanic White women, Hispanic women, while being more likely to breastfeed initially (aOR 1.40, 95%CI 1.02–1.92), were less likely to breastfeed for 6 months (aOR 0.72, 95%CI 0.59–0.88). While non-Hispanic Black women were less likely than non-Hispanic White women to initiate breastfeeding (aOR 0.68, 95%CI 0.51–0.90), the odds of non-Hispanic Black women of continuing to breastfeed for at least 6 months was similar to non-Hispanic White women (aOR 0.92, 95%CI 0.71–1.19).

Conclusions

In this cohort of women giving birth for the first time, duration of breastfeeding was associated with several characteristics which highlight groups at greater risk of not breastfeeding as long as currently recommended.

Trial registration

NCT01322529 (nuMoM2b) and NCT02231398 (nuMoM2b-Heart Health)

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-05038-7.

Association of Genetic Predisposition and Physical Activity With Risk of Gestational Diabetes in Nulliparous Women

IMPORTANCE

Polygenic risk scores (PRS) for type 2 diabetes (T2D) can improve risk prediction for gestational diabetes (GD), yet the strength of the association between genetic and lifestyle risk factors has not been quantified.

OBJECTIVE

To assess the association of PRS and physical activity in existing GD risk models and identify patient subgroups who may receive the most benefits from a PRS or physical activity intervention.

DESIGN, SETTINGS, AND PARTICIPANTS

The Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be cohort was established to study individuals without previous pregnancy lasting at least 20 weeks (nulliparous) and to elucidate factors associated with adverse pregnancy outcomes. A subcohort of 3533 participants with European ancestry was used for risk assessment and performance evaluation. Participants were enrolled from October 5, 2010, to December 3, 2013, and underwent genotyping between February 19, 2019, and February 28, 2020. Data were analyzed from September 15, 2020, to November 10, 2021.

EXPOSURES

Self-reported total physical activity in early pregnancy was quantified as metabolic equivalents of task (METs). Polygenic risk scores were calculated for T2D using contributions of 84 single nucleotide variants, weighted by their association in the Diabetes Genetics Replication and Meta-analysis Consortium data.

MAIN OUTCOMES AND MEASURES

Estimation of the development of GD from clinical, genetic, and environmental variables collected in early pregnancy, assessed using measures of model discrimination. Odds ratios and positive likelihood ratios were used to evaluate the association of PRS and physical activity with GD risk.

RESULTS

A total of 3533 women were included in this analysis (mean [SD] age, 28.6 [4.9] years). In high-risk population subgroups (body mass index ≥25 or aged ≥35 years), individuals with high PRS (top 25th percentile) or low activity levels (METs <450) had increased odds of a GD diagnosis of 25% to 75%. Compared with the general population, participants with both high PRS and low activity levels had higher odds of a GD diagnosis (odds ratio, 3.4 [95% CI, 2.3-5.3]), whereas participants with low PRS and high METs had significantly reduced risk of a GD diagnosis (odds ratio, 0.5 [95% CI, 0.3-0.9]; P = .01).

CONCLUSIONS AND RELEVANCE

In this cohort study, the addition of PRS was associated with the stratified risk of GD diagnosis among high-risk patient subgroups, suggesting the benefits of targeted PRS ascertainment to encourage early intervention.

Instituting a Curriculum for Cardio-Obstetrics Subspecialty Fellowship Training

Maternal mortality is rising in the United States, and cardiovascular disease is the leading cause. Adverse pregnancy outcomes such as preeclampsia and gestational diabetes heighten the risk of cardiovascular complications during pregnancy and the peripartum period and are associated with long-term cardiovascular risks. The field of cardio-obstetrics is a subspecialty within adult cardiology that focuses on the management of women with or at high risk for heart disease who are considering pregnancy or have become pregnant. There is growing recognition of the need for more specialists with dedicated expertise in cardio-obstetrics to improve the cardiovascular care of this high-risk patient population. Current recommendations for cardiovascular fellowship training programs accredited by the Accreditation Council for Graduate Medical Education involve establishing core competency in the knowledge of managing heart disease in pregnancy. However, little granular detail is available of what such training should entail, which can lead to knowledge gaps. Additionally, dedicated advanced subspecialty training in this area is not commonly offered. Multidisciplinary collaborative teams have been shown to improve outcomes in cardiac patients during pregnancy, and cardiovascular fellows-in-training interested in cardio-obstetrics should have the opportunity to participate in and contribute to a pregnancy heart team. In this document, we describe a proposed specialized cardio-obstetrics training pathway that could serve to adequately prepare trainees to competently and comprehensively care for women with cardiovascular disease before, during, and after pregnancy.

Association between aspirin use during pregnancy and cardiovascular risk factors 2-7 years after delivery: The nuMoM2b Heart Health Study

OBJECTIVES

To evaluate the association between aspirin use during first pregnancy and later maternal cardiovascular risk.

STUDY DESIGN

In this secondary analysis of a prospective cohort, we included participants who carried their first pregnancy to 20 + weeks, had data regarding aspirin use, and attended a study visit 2-7 years following delivery. The exposure was aspirin use during the first pregnancy. We calculated aspirin use propensity scores from logistic regression models including baseline variables associated with aspirin use in pregnancy and cardiovascular risk. Outcomes of interest were incident cardiovascular-related diagnoses 2-7 years following delivery. Robust Poisson regression calculated the risk of outcomes by aspirin exposure, adjusting for the aspirin use propensity score.

MAIN OUTCOME MEASURES

The primary outcome was a composite of incident cardiovascular diagnoses at the time of the study visit: cardiovascular events, chronic hypertension, metabolic syndrome, prediabetes or type 2 diabetes, dyslipidemia, and chronic kidney disease.

RESULTS

Of 4,480 women included, 84 (1.9%) reported taking aspirin during their first pregnancy. 52.6% of participants in the aspirin-exposed group and 43.0% in the unexposed group had the primary outcome. After adjusting for the aspirin use propensity scores, aspirin use during the first pregnancy was not associated with any of the outcomes.

CONCLUSION

We did not detect an association between aspirin use during the first pregnancy and cardiovascular-related diagnoses 2-7 years later. Our study was only powered to detect a large difference in relative risk, so we cannot rule out a smaller difference that may be clinically meaningful.

Sleep-disordered Breathing in Pregnancy and after Delivery: Associations with Cardiometabolic Health

Rationale: Knowledge gaps exist regarding health implications of sleep-disordered breathing (SDB) identified in pregnancy and/or after delivery. Objectives: To determine whether SDB in pregnancy and/or after delivery is associated with hypertension (HTN) and metabolic syndrome (MS). Methods: nuMoM2b-HHS (Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-be Heart Health Study) (N = 4,508) followed participants initially recruited during their first pregnancy. Participants returned for a visit 2-7 years after pregnancy. This study examined a subgroup who underwent SDB assessments during their first pregnancy (n = 1,964) and a repeat SDB assessment after delivery (n = 1,222). Two SDB definitions were considered: 1) apnea-hypopnea index (AHI) ⩾ 5 and 2) oxygen desaturation index (ODI) ⩾ 5. Associations between SDB and incident HTN and MS were evaluated with adjusted risk ratios (aRRs). Measurements and Main Results: The aRR for MS given an AHI ⩾ 5 during pregnancy was 1.44 (95% confidence interval [CI], 1.08-1.93), but no association with HTN was found. ODI ⩾ 5 in pregnancy was associated with both an increased risk for HTN (aRR, 2.02; 95% CI, 1.30-3.14) and MS (aRR, 1.53; 95% CI, 1.19-1.97). Participants with an AHI ⩾ 5 in pregnancy that persisted after delivery were at higher risk for both HTN (aRR, 3.77; 95% CI, 1.84-7.73) and MS (aRR, 2.46; 95% CI, 1.59-3.76). Similar associations were observed for persistent ODI ⩾ 5 after delivery. Conclusions: An AHI ⩾ 5 in pregnancy was associated with an increased risk of MS. An ODI ⩾ 5 in pregnancy was significantly associated with both HTN and MS. Participants with persistent elevations in AHI and ODI during pregnancy and at 2-7 years after delivery were at the highest risk for HTN and MS. Clinical trial registered with www.clinicaltrials.gov (NCT02231398).

Association of N-Terminal Pro-Brain Natriuretic Peptide Concentration in Early Pregnancy With Development of Hypertensive Disorders of Pregnancy and Future Hypertension

IMPORTANCE

Hypertensive disorders of pregnancy are associated with future cardiovascular disease, perhaps because of subclinical cardiac dysfunction before pregnancy leading to impaired adaptation to pregnancy. Natriuretic peptides are promising biomarkers for detecting subclinical cardiac dysfunction outside of pregnancy.

OBJECTIVE

To investigate whether higher concentrations of N-terminal pro-brain natriuretic peptide (NT-proBNP) in early pregnancy would be associated with hypertensive disorders of pregnancy and hypertension 2 to 7 years post partum.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used data from the The Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be Heart Health Study, a prospective multicenter observational study. A total of 4103 nulliparous women with complete data and no prepregnancy hypertension or diabetes who were treated at 8 clinical sites were included. Women were followed up with for 2 to 7 years after pregnancy. Data were collected from October 2010 to October 2017, and data were analyzed from August 2020 to November 2021.

EXPOSURES

NT-proBNP concentration, measured using an electrochemiluminescence immunoassay from a first-trimester blood sample.

MAIN OUTCOMES AND MEASURES

Hypertensive disorders of pregnancy and incident hypertension (systolic blood pressure of 130 mm Hg or diastolic blood pressure of 80 mm Hg or use of antihypertensive agents) at follow-up visit.

RESULTS

A total of 4103 women met inclusion criteria; the mean (SD) age was 27.0 (5.6) years. Among these women, 909 (22.2%) had an adverse pregnancy outcome, and 817 (19.9%) had hypertension at the follow-up visit. Higher NT-proBNP concentrations were associated with a lower risk of hypertensive disorders of pregnancy (adjusted odds ratio per doubling, 0.81; 95% CI, 0.73-0.91), which persisted after adjustment for age, self-reported race and ethnicity, early-pregnancy body mass index, smoking, and aspirin use. Similarly, higher NT-proBNP concentration in early pregnancy was also associated with a lower risk of incident hypertension 2 to 7 years after delivery (adjusted odds ratio per doubling, 0.84; 95% CI, 0.77-0.93), an association that persisted after controlling for confounders, including hypertensive disorders of pregnancy.

CONCLUSIONS AND RELEVANCE

In this cohort study, higher NT-proBNP concentrations in early pregnancy were associated with a lower risk of hypertensive disorders of pregnancy and hypertension 2 to 7 years post partum. These findings suggest that normal early-pregnancy cardiovascular physiology, as assessed by NT-proBNP concentration, may provide biologic insights into both pregnancy outcome and cardiovascular disease risk.

Cardiometabolic health after first pregnancy: Associations with social determinants of health. A nuMoM2b-HHS study

Study objective

This study sought to evaluate the associations between social determinants of health (SDOH) at the time of first pregnancy and subsequent cardiometabolic health, defined as the development of metabolic syndrome.

Design

nuMoM2b-HHS (Nulliparous Pregnancy Outcomes Study- Monitoring Mothers-to-Be-Heart Health Study) is an ongoing prospective cohort study.

Setting

Eight academic medical centers enrolled and continue to follow participants.

Participants

4484 participants followed a mean of 3.2 years from the time of their first pregnancy.

Interventions

N/a.

Main outcome measure

Unadjusted and adjusted Poisson regression models with robust standard errors were used to obtain relative risks and 95% confidence intervals estimating the risk of metabolic syndrome for each baseline SDOH. In secondary analyses we examined the associations between SDOH and incident hypertension, obesity, and diabetes mellitus.

Results

Metabolic syndrome developed in 13.6% of participants. Higher socioeconomic position at the time of pregnancy was associated with lower rates of metabolic syndrome [income > 200% poverty level aRR 0.55 (95% CI, 0.42-0.71), attainment of a bachelor's degree aRR 0.62 (0.46-0.84) or higher aRR 0.50 (0.35-0.71)], while being single [aRR 1.45 (95% CI, 1.18-1.77)] and having low health literacy were associated with a greater risk of metabolic syndrome [aRR 1.98 (95% CI, 1.28-3.07)].

Conclusions

Over a short interval following first pregnancy, participants accumulated high proportions of cardiovascular risk factors and metabolic syndrome, with some risk associated with SDOH. The impact of interventions addressing SDOH in pregnant people on cardiometabolic health should be tested as a means of reducing health inequities at the population level.

Multicenter Cohort Study, With a Nested Randomized Comparison, to Examine the Cardiovascular Impact of Preterm Preeclampsia

[Figure: see text].

Association of second trimester uterine artery Doppler parameters with maternal hypertension 2–7 years after delivery

Background

Reduced uterine artery compliance is associated with adverse pregnancy outcomes (APOs) and may indicate underlying maternal cardiovascular pathology. We investigated associations between second trimester uterine artery Doppler (UAD) parameters and incident maternal hypertension 2–7 years after delivery.

Methods

A cohort of 10,038 nulliparous US participants was recruited early in pregnancy. A subgroup of 3739, without baseline hypertension and with complete follow-up visits 2–7 years after delivery, were included in this analysis. We investigated UAD indicators of compliance including: 1) early diastolic notch; 2) resistance index (RI); and 3) pulsatility index (PI). We defined hypertension as systolic blood pressure ≥130 mmHg, diastolic ≥80 mmHg, or antihypertensive medication use. We calculated odds ratios (OR) and 95 % confidence intervals (95%CI) for associations between UAD parameters and hypertension, adjusting for age, obesity, race/ethnicity, insurance, smoking, and APOs.

Results

A total of 187 (5 %) participants developed hypertension after the index pregnancy. Presence of early diastolic notch on UAD was not associated with incident hypertension. Increased RI and PI correlated with higher odds of hypertension (RI: adjusted OR 1.15 [95 % CI 1.03–1.30]; PI: adjusted OR 1.03 [95%CI 1.01–1.05] for each 0.1 unit increase). Maximum RI above 0.84 or maximum PI above 2.3 more than doubled the odds of incident hypertension (RI: adjusted OR 2.49, 95%CI 1.45–4.26; PI: adjusted OR 2.36, 95%CI 1.45–3.86).

Conclusion

Higher resistance and pulsatility indices measured on second trimester UAD were associated with increased odds of incident hypertension 2–7 years later, and may be biomarkers of higher maternal cardiovascular risk.

Objectively assessed sleep-disordered breathing during pregnancy and infant birthweight

BACKGROUND

Sleep-disordered breathing (SDB) in pregnancy is associated with adverse maternal outcomes. The relationship between SDB and infant birthweight is unclear. This study's primary aim is to determine if objectively measured SDB in pregnancy is associated with infant birthweight.

METHODS

We measured SDB objectively in early (6-15 weeks' gestation) and mid (22-31 weeks' gestation) pregnancy in a large cohort of nulliparous women. SDB was defined as an Apnea-Hypopnea Index ≥5 and in secondary analyses we also examined measures of nocturnal hypoxemia. We used a modified Poisson regression approach to estimate relative risks (RR) of large-for-gestational-age (LGA: >90th percentile for gestational age) and small-for-gestational-age (SGA: <10th percentile for gestational age) birthweights.

RESULTS

The prevalence of early-pregnancy SDB was nearly 4%. The incidence of mid-pregnancy SDB was nearly 6.0%. The prevalence of LGA and SGA was 7.4% and 11.9%, respectively. Early-pregnancy SDB was associated with a higher risk of LGA in unadjusted models (RR 2.2, 95% CI 1.3-3.5) but not BMI-adjusted models (aRR 1.0, 95% CI 0.6-1.8). Mid-pregnancy SDB was not associated with SGA or LGA. Mid-pregnancy nocturnal hypoxemia (% of sleep time <90% oxygen saturation) and increasing nocturnal hypoxemia from early to mid-pregnancy were associated with a higher risk of LGA in BMI-adjusted models. SDB and nocturnal hypoxemia were not associated with SGA.

CONCLUSIONS

SDB in pregnancy was not associated with an increased risk of LGA or SGA birthweight, independent of BMI. Some measures nocturnal hypoxemia were associated with an increase in LGA risk, independent of BMI. ClinicalTrials.gov Registration number NCT02231398.

Early Pregnancy Atherogenic Profile in a First Pregnancy and Hypertension Risk 2 to 7 Years After Delivery

Background

Cardiovascular risk in young adulthood is an important determinant of lifetime cardiovascular disease risk. Women with adverse pregnancy outcomes (APOs) have increased cardiovascular risk, but the relationship of other factors is unknown.

Methods and Results

Among 4471 primiparous women, we related first‐trimester atherogenic markers to risk of APO (hypertensive disorders of pregnancy, preterm birth, small for gestational age), gestational diabetes mellitus (GDM) and hypertension (130/80 mm Hg or antihypertensive use) 2 to 7 years after delivery. Women with an APO/GDM (n=1102) had more atherogenic characteristics (obesity [34.2 versus 19.5%], higher blood pressure [systolic blood pressure 112.2 versus 108.4, diastolic blood pressure 69.2 versus 66.6 mm Hg], glucose [5.0 versus 4.8 mmol/L], insulin [77.6 versus 60.1 pmol/L], triglycerides [1.4 versus 1.3 mmol/L], and high‐sensitivity C‐reactive protein [5.6 versus 4.0 nmol/L], and lower high‐density lipoprotein cholesterol [1.8 versus 1.9 mmol/L]; P<0.05) than women without an APO/GDM. They were also more likely to develop hypertension after delivery (32.8% versus 18.1%, P<0.05). Accounting for confounders and factors routinely assessed antepartum, higher glucose (relative risk [RR] 1.03 [95% CI, 1.00–1.06] per 0.6 mmol/L), high‐sensitivity C‐reactive protein (RR, 1.06 [95% CI, 1.02–1.11] per 2‐fold higher), and triglycerides (RR, 1.27 [95% CI, 1.14–1.41] per 2‐fold higher) were associated with later hypertension. Higher physical activity was protective (RR, 0.93 [95% CI, 0.87‐0.99] per 3 h/week). When evaluated as latent profiles, the nonobese group with higher lipids, high‐sensitivity C‐reactive protein, and insulin values (6.9% of the cohort) had increased risk of an APO/GDM and later hypertension. Among these factors, 7% to 15% of excess RR was related to APO/GDM.

Conclusions

Individual and combined first‐trimester atherogenic characteristics are associated with APO/GDM occurrence and hypertension 2 to 7 years later.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02231398.

Association of Adverse Pregnancy Outcomes With Risk of Atherosclerotic Cardiovascular Disease in Postmenopausal Women

Importance

Atherosclerotic cardiovascular disease (ASCVD) may have unique risk factors in women. Most women have a history of pregnancy; common adverse pregnancy outcomes (APOs) appear to be associated with ASCVD, but prior studies have limitations.

Objective

To assess whether APOs are associated with increased ASCVD risk independently of traditional risk factors.

Design, Setting, and Participants

The APO history among participants in the Women's Health Initiative, a large multiethnic cohort of postmenopausal women, was assessed. The associations of 5 self-reported APOs (gestational diabetes, hypertensive disorders of pregnancy, low birth weight [ie, birth weight less than 2.49 kg], high birth weight [ie, birth weight greater than 4.08 kg], and preterm delivery by 3 weeks or more) with ASCVD were analyzed, adjusting for traditional ASCVD risk factors. Data were collected and analyzed in 2017.

Exposures

APOs (gestational diabetes, hypertensive disorders of pregnancy, low birth weight, high birth weight, and preterm delivery).

Main Outcomes and Measures

Adjudicated ASCVD.

Results

A total of 48 113 Women's Health Initiative participants responded to the survey; the median (interquartile range) age at time of enrollment was 60.0 (55.0-64.0) years. A total of 13 482 participants (28.8%) reported 1 or more APOs. Atherosclerotic cardiovascular disease was more frequent in women who reported an APO compared with those without APOs (1028 of 13 482 [7.6%] vs 1758 of 30 522 [5.8%]). Each APO, analyzed separately, was significantly associated with ASCVD, and gestational diabetes, hypertensive disorders of pregnancy, low birth weight, and preterm delivery remained significant after adjustment for traditional ASCVD risk factors. When all APOs were analyzed together, hypertensive disorders of pregnancy (odds ratio, 1.27; 95% CI, 1.15-1.40) and low birth weight (odds ratio, 1.12; 95% CI, 1.00-1.26) remained independently associated with ASCVD. All findings were materially unchanged by additional adjustment for parity, body mass index, and socioeconomic factors.

Conclusions and Relevance

In this large multiethnic cohort of women, hypertensive disorders of pregnancy and low birth weight were independently associated with ASCVD after adjustment for risk factors and other APOs.

Development and Internal Validation of a Model Predicting Premature Cardiovascular Disease Among Women With Hypertensive Disorders of Pregnancy: A Population-Based Study in Quebec, Canada

Background

Hypertensive disorders of pregnancy (HDP) are associated with an increased risk of premature cardiovascular disease (CVD), but existing cardiovascular prediction models do not adequately capture risks in young women. We developed a model to predict the 10‐year risk of premature CVD and mortality among women who have HDP.

Methods and Results

Using a population‐based cohort of women with HDP who delivered between April 1989 and March 2017 in Quebec, Canada, we developed a 10‐year CVD risk model using Cox proportional hazards regression. Women aged 18 to 45 years were followed from their first HDP‐complicated delivery until March 2018. We assessed performance of the model based on discrimination, calibration, and risk stratification ability. Internal validity was assessed using the bootstrap method. The cohort included 95 537 women who contributed 1 401 084 person‐years follow‐up. In total, 4024 (4.2%) of women were hospitalized for CVD, of which 1585 events (1.6%) occurred within 10 years of follow‐up. The final model had modest discriminatory performance (area under the receiver operating characteristic curve, 0.66; 95% CI, 0.65–0.67) and good calibration with slope of 0.95 and intercept of −0.19. There was moderate classification accuracy (likelihood ratio+: 5.90; 95% CI, 5.01–6.95) in the highest‐risk group upon risk stratification.

Conclusions

Overall, our model had modest performance in predicting the 10‐year risk of premature CVD for women with HDP. We recommend the addition of clinical variables, and external validation, before consideration for clinical use.

Associations of perceived prenatal stress and adverse pregnancy outcomes with perceived stress years after delivery

Maternal stress is a risk factor for adverse pregnancy outcomes (APOs). This study evaluates the associations of prenatal stress and APOs with maternal stress years after pregnancy. The 10-item Perceived Stress Scale (PSS) (0-40 range) was completed in the first and third trimesters, and 2-7 years after delivery among a subsample (n = 4161) of nulliparous women enrolled at eight US medical centers between 2010 and 2013 in a prospective, observational cohort study. Demographics, medical history, and presence of APOs (gestational diabetes (GDM), hypertensive disorders of pregnancy (HDP), preeclampsia (PE), and medically indicated or spontaneous preterm birth (miPTB, sPTB)) were obtained. The associations of prenatal PSS and the presence of APOs with PSS scores years after delivery were estimated using multivariable linear regression. Mean PSS scores were 12.5 (95% CI 12.3, 12.7) and 11.3 (95% CI 11.1, 11.5) in the first and third trimesters respectively and 14.9 (95% CI 14.7, 15.1) 2-7 years later, an average increase of 2.4 points (95% CI 2.2, 2.6) from the start of pregnancy. Regressing PSS scores after delivery on first-trimester PSS and PSS increase through pregnancy showed positive associations, with coefficients (95% CI) of 2.8 (2.7, 3.0) and 1.5 (1.3, 1.7) per 5-point change, respectively. Adding APO indicator variables separately showed higher PSS scores for women with HDP (0.7 [0.1, 1.3]), PE (1.3 [0.6, 2.1]), and miPTB (1.3 [0.2, 2.4]), but not those with GDM or sPTB. In this geographically and demographically diverse sample, prenatal stress and some APOs were positively associated with stress levels 2-7 years after pregnancy.ClinicalTrials.gov Registration number NCT02231398.

Association of Adverse Pregnancy Outcomes With Hypertension 2 to 7 Years Postpartum

Background Identifying pregnancy-associated risk factors before the development of major cardiovascular disease events could provide opportunities for prevention. The objective of this study was to determine the association between outcomes in first pregnancies and subsequent cardiovascular health. Methods and Results The Nulliparous Pregnancy Outcomes Study Monitoring Mothers-to-be Heart Health Study is a prospective observational cohort that followed 4484 women 2 to 7 years (mean 3.2 years) after their first pregnancy. Adverse pregnancy outcomes (defined as hypertensive disorders of pregnancy, small-for-gestational-age birth, preterm birth, and stillbirth) were identified prospectively in 1017 of the women (22.7%) during this pregnancy. The primary outcome was incident hypertension (HTN). Women without adverse pregnancy outcomes served as controls. Risk ratios (RR) and 95% CIs were adjusted for age, smoking, body mass index, insurance type, and race/ethnicity at enrollment during pregnancy. The overall incidence of HTN was 5.4% (95% CI 4.7% to 6.1%). Women with adverse pregnancy outcomes had higher adjusted risk of HTN at follow-up compared with controls (RR 2.4, 95% CI 1.8-3.1). The association held for individual adverse pregnancy outcomes: any hypertensive disorders of pregnancy (RR 2.7, 95% CI 2.0-3.6), preeclampsia (RR 2.8, 95% CI 2.0-4.0), and preterm birth (RR 2.7, 95% CI 1.9-3.8). Women who had an indicated preterm birth and hypertensive disorders of pregnancy had the highest risk of HTN (RR 4.3, 95% CI 2.7-6.7). Conclusions Several pregnancy complications in the first pregnancy are associated with development of HTN 2 to 7 years later. Preventive care for women should include a detailed pregnancy history to aid in counseling about HTN risk. Clinical Trial Registration URL: http://www.clinicaltrials.gov Unique identifier: NCT02231398.

Obstructive Sleep Apnea in Pregnant Women: A Review of Pregnancy Outcomes and an Approach to Management

Among obese pregnant women, 15%-20% have obstructive sleep apnea (OSA) and this prevalence increases along with body mass index and in the presence of other comorbidities. Prepregnancy obesity and pregnancy-related weight gain are certainly risk factors for sleep-disordered breathing in pregnancy, but certain physiologic changes of pregnancy may also increase a woman's risk of developing or worsening OSA. While it has been shown that untreated OSA in postmenopausal women is associated with a range of cardiovascular, pulmonary, and metabolic comorbidities, a body of literature is emerging that suggests OSA may also have serious implications for the health of mothers and fetuses during and after pregnancy. In this review, we discuss the following: pregnancy as a vulnerable period for the development or worsening of OSA; the associations between OSA and maternal and fetal outcomes; the current screening modalities for OSA in pregnancy; and current recommendations regarding peripartum management of OSA.

Pregnancy Complications as a Window to Future Cardiovascular Disease

Pregnancy is a time of significant hemodynamic, metabolic, and hormonal stress that can unmask underlying subclinical cardiovascular abnormalities, and pregnancy-related complications may serve as early warning signs for future risk of cardiovascular disease. The increased recognition of these sex-specific risk factors could identify women who may benefit from more intensive risk factor modification to reduce morbidity and mortality later in life. In this review, we describe several pregnancy-related complications that have been associated with the risk of cardiovascular disease, including hypertensive disorders of pregnancy, gestational diabetes mellitus, preterm delivery, and pregnancy loss. Pregnancy-associated risk factors must be identified to fully assess a woman's future cardiovascular risk and may influence strategies for risk reduction.

Patterns of leisure-time physical activity across pregnancy and adverse pregnancy outcomes

Background

Although leisure-time physical activity (PA) contributes to overall health, including pregnancy health, patterns across pregnancy have not been related to birth outcomes. We hypothesized that women with sustained low leisure-time PA would have excess risk of adverse pregnancy outcomes, and that changing patterns across pregnancy (high to low and low to high) may also be related to risk of adverse pregnancy outcomes.

Methods

Nulliparous women (n = 10,038) were enrolled at 8 centers early in pregnancy (mean gestational age in weeks [SD] = 12.05 [1.51]. Frequency, duration, and intensity (metabolic equivalents) of up to three leisure activities reported in the first, second and third trimesters were analyzed. Growth mixture modeling was used to identify leisure-time PA patterns across pregnancy. Adverse pregnancy outcomes (preterm birth, [PTB, overall and spontaneous], hypertensive disorders of pregnancy [HDP], gestational diabetes [GDM] and small-for-gestational-age births [SGA]) were assessed via chart abstraction.

Results

Five patterns of leisure-time PA across pregnancy were identified: High (35%), low (18%), late decreasing (24%), early decreasing (10%), and early increasing (13%). Women with sustained low leisure-time PA were younger and more likely to be black or Hispanic, obese, or to have smoked prior to pregnancy. Women with low vs. high leisure-time PA patterns had higher rates of PTB (10.4 vs. 7.5), HDP (13.9 vs. 11.4), and GDM (5.7 vs. 3.1, all p < 0.05). After adjusting for maternal factors (age, race/ethnicity, BMI and smoking), the risk of GDM (Odds ratio 2.00 [95% CI 1.47, 2.73]) remained higher in women with low compared to high patterns. Early and late decreasing leisure-time PA patterns were also associated with higher rates of GDM. In contrast, women with early increasing patterns had rates of GDM similar to the group with high leisure-time PA (3.8% vs. 3.1%, adjusted OR 1.16 [0.81, 1.68]). Adjusted risk of overall PTB (1.31 [1.05, 1.63]) was higher in the low pattern group, but spontaneous PTB, HDP and SGA were not associated with leisure-time PA patterns.

Conclusions

Sustained low leisure-time PA across pregnancy is associated with excess risk of GDM and overall PTB compared to high patterns in nulliparous women. Women with increased leisure-time PA early in pregnancy had low rates of GDM that were similar to women with high patterns, raising the possibility that early pregnancy increases in activity may be associated with improved pregnancy health.

Trial registration

Registration number NCT02231398.

Electronic supplementary material

The online version of this article (10.1186/s12966-018-0701-5) contains supplementary material, which is available to authorized users.

A review of the associations between obstructive sleep apnea and hypertensive disorders of pregnancy and possible mechanisms of disease

Obesity is prevalent among pregnant women in the United States; 15-20% of obese pregnant women have obstructive sleep apnea. The prevalence of obstructive sleep apnea increases along with body mass index, age and in the presence of other co-morbidities. Untreated obstructive sleep apnea in women is associated with a range of cardiovascular, pulmonary and metabolic co-morbidities; recent studies suggest that women with obstructive sleep apnea in pregnancy may be at significantly greater risk of entering pregnancy with chronic hypertension and/or of developing hypertensive disorders of pregnancy: gestational hypertension; preeclampsia; or eclampsia. This has serious public health implications; hypertensive disorders of pregnancy are a major cause of maternal and neonatal morbidity and mortality and are associated with a greater lifetime risk for cardiovascular disease. The mechanisms that associated obstructive sleep apnea with hypertensive disorders of pregnancy have not been defined, but several pathways are scientifically plausible. In this review, we will present a comprehensive literature review of the following: the associations between obstructive sleep apnea and hypertensive disorders of pregnancy; the proposed mechanisms that may connect obstructive sleep apnea and hypertensive disorders of pregnancy; and the effectiveness of treatment at mitigating these adverse outcomes.

Invited Commentary: Gestational Hypertension and Diabetes-A Major Public Health Concern

The obesity epidemic in the United States and other countries has contributed to an increase in the rates of gestational diabetes and hypertension. In the past, it was thought that most cases of gestational diabetes and hypertension would resolve after completion of pregnancy. In this issue of the Journal, Pace et al. (Am J Epidemiol. 2017;186(10):1115-1124) clearly documented that both gestational diabetes and hypertension lead to diabetes and hypertension and that the combination of both during pregnancy leads to very high rates of subsequent diabetes and hypertension. A new generation of epidemiology studies using the evolving new technologies and genetics (host susceptibility studies) are needed to improve our understanding of the etiology of gestational diabetes and hypertension. Early identification of women at risk of gestational diabetes and hypertension, better treatment during pregnancy, and preventive and clinical therapies for treatment of diabetes and hypertension after pregnancy are very important for improving women's health and reducing risk of cardiovascular disease later in life.

Cumulative Lactation and Onset of Hypertension in African-American Women

Hypertension affects nearly 1 of 3 women and contributes to cardiovascular disease, the leading cause of death in the United States. Breastfeeding leads to metabolic changes that could reduce risks of hypertension. Hypertension disproportionately affects black women, but rates of breastfeeding among black women lag behind those in the general population. In the Black Women's Health Study (n = 59,001), we conducted a nested case-control analysis using unconditional logistic regression to estimate the association between breastfeeding and incident hypertension at ages 40-65 years using data collected from 1995 to 2011. Controls were frequency-matched 2:1 to 12,513 hypertensive women by age and questionnaire cycle. Overall, there was little evidence of association between ever breastfeeding and incident hypertension (odds ratio = 0.97, 95% confidence interval: 0.92, 1.02). However, age modified the relationship (P = 0.02): Breastfeeding was associated with reduced risk of hypertension at ages 40-49 years (odds ratio = 0.92, 95% confidence interval: 0.85, 0.99) but not at older ages. In addition, risk of hypertension at ages 40-49 years decreased with increasing duration of breastfeeding (P for trend = 0.08). Our results suggest that long-duration breastfeeding may reduce the risk of incident hypertension in middle age. Addressing breastfeeding as a potential preventative health behavior is particularly compelling because it is required for only a discrete period of time.

Irresponsible and responsible resource management in obstetrics

Low budgets constrain and high budgets stimulate choices. In high-income countries, this economic reality may lead to overuse of healthcare services and pose unnecessary risks for mothers and infants. Options for improvement can be created at different levels of healthcare systems. Pregnancy provides an effective opportunity to profile maternal risks and represents a vulnerable but potentially modifiable period from prenatal life to adulthood. In response to system-inherent false incentives, professional responsibility requires obstetricians to strive to improve the future health of families and their offspring despite disincentives for doing so. This chapter addresses professionally responsible resource management in obstetrics and identifies implications for patients, care givers, communities, policy makers, and academic faculties.