Predicting Women’s Future Cardiovascular Health from Pregnancy Complications

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.

Cardiovascular Disease-Related Pregnancy Complications Are Associated with Increased Maternal Levels and Trajectories of Cardiovascular Disease Biomarkers During and After Pregnancy

Background: Having a pregnancy complicated by hypertensive disorders of pregnancy (HDP) and/or having a small or preterm baby put a woman at risk for later cardiovascular disease (CVD). It is uncertain if higher maternal CVD risk factors (reflected by increased peripartum CVD biomarker levels) account for this risk, or if experiencing a complicated pregnancy itself increases a woman's CVD risk (reflected by an increase in biomarker trajectories from early pregnancy to postpartum). Methods: We conducted a secondary analysis of an 8-week mindful eating and stress reduction intervention in 110 pregnant women. We used mixed linear regression analysis to compare CVD biomarker levels and trajectories, between women with and without a CVD-related pregnancy complication (including HDP [gestational hypertension or preeclampsia] or having a small for gestational age [<10th percentile] or preterm [<37 weeks] baby), at three times: (1) 12-20 weeks of gestation, (2) 3 months postpartum, and (3) 9 months postpartum. CVD biomarkers studied included serum glucose, insulin, homeostasis model assessment of insulin resistance (HOMA-IR), body mass index (BMI), blood pressure (BP), interleukin-6 (IL-6), tumor necrosis factor, and lipids. We adjusted for age, maternal smoking, prepregnancy BMI, BP, age × time, and BMI × time. Results: Women had a mean age of 28 years (standard deviation [SD] 6), mean prior pregnancies of 0.8 (SD 1.0), and 22 women had one or more CVD-related pregnancy complications. HOMA-IR, diastolic BP, triglyceride, high-density lipoprotein cholesterol, and IL-6 average levels, but not trajectories, differed among women with complicated versus normal pregnancy (all p values were ≤0.04). Peripartum glucose and systolic BP trajectories were statistically greater in complicated versus normal pregnancies (p values were 0.008 and 0.01, respectively). Conclusion: We conclude that the experience of a complicated pregnancy in addition to elevated CVD risk factor levels may both increase a woman's risk of future CVD. ClinicalTrials.gov Identifier: NCT01307683.

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.

Association of Pregnancy Complications and Characteristics With Future Risk of Elevated Blood Pressure: The Västerbotten Intervention Program

Pregnancy characteristics are associated with risk of cardiovascular diseases, but their independent associations with hypertension or blood pressure (BP) levels remain uncertain. We linked the Swedish Medical Birth Register with Västerbotten Intervention Program data (Northern Sweden). Using linear and logistic regression, we related pregnancy factors in any prior pregnancy with BP and hypertension at 40 years of age in 15 896 parous women free of prepregnancy hypertension. Pregnancy factors included parity, age at first delivery, preeclampsia, gestational diabetes mellitus, placental abruption, shortest gestational age small for gestational age baby (<third percentile for birth weight) or stillbirth. We defined hypertension as systolic BP ≥140 mm Hg and diastolic BP ≥90 mm Hg or antihypertensive use. Multivariable models were adjusted for all pregnancy factors and potential lifestyle and sociodemographic confounders. At 40 years of age, 1535 women (9.6%) had hypertension. In multivariable models, lower parity, younger age at first birth, preeclampsia, small for gestational age, and placental abruption were independently associated with higher systolic and diastolic BP levels at 40 years of age. Younger age at first birth, preeclampsia, gestational age <32 versus ≥37 weeks, and small for gestational age were independently associated with hypertension. Our findings raise the possibility that earlier and more frequent BP screening may be desirable in women with these pregnancy characteristics.

[Assessment of central hemodynamic properties of the arterial wall in women with previous preeclampsia]

BACKGROUND

We investigated viscoelastic properties of the arterial wall in women with previous preeclampsia (PE) compared to those with normal pregnancy (NP).

METHODS

In a cross-sectional study 45 women with previous PE and 55 with NP were included, matched for age (PE 38±6 vs. NP 38±5 years, NS) and body mass index: (PE 25±4 vs. NP 26±4 kg/m(2), NS) studied, respectively, 76±34 and 86±48 months after delivery. We assessed arterial distensibility - pulse wave velocity (PWV, Complior) and reflected waves (augmentation pressure [AP], mmHg) and augmentation index (AIx) - in the central pressure wave and blood pressure (BP) on 24-h ambulatory BP monitoring (ABPM).

RESULTS

PE showed higher (p<0.01) peripheral systolic blood pressure (SBP): PE 131±18 vs. NP 121±19, and central SBP: PE 122±18 vs. NP 110±19 mmHg, with less amplification of central-peripheral pressure: PE 10±4 vs. NP 12±5, p=0.041, and higher (p<0.05) AP: PE 10±3 vs. NP 8±2, and AIx: PE 26±5 vs. NP 20±5 mmHg, but PE and NP did not differ in pulse wave velocity. On ABPM, PE (n=39) vs. NP (n=33) had higher nighttime SBP: PE 121±10 vs. NP 108±10 mmHg and lower percentage nocturnal SBP fall: PE 11±6 vs. NP 18±11%, both p<0.02. During follow-up, the need for antihypertensive medication was seven times higher in PE than in NP.

CONCLUSION

Women with previous PE have a greater risk of hypertension, higher nighttime BP values, blunted nocturnal BP fall and changes in central pressure suggestive of increased reflected waves and peripheral vascular resistance. These factors may contribute to their higher cardiovascular risk after pregnancy.