Pre-gravid predictors of new onset hypertension in pregnancy − Results from a pre-conception cohort study in China

Maternal adiposity measures and hypertensive disorders of pregnancy: a meta-analysis

BACKGROUND

Hypertensive disorders of pregnancy (HDP) are a prevalent complication during pregnancy with significant implications for maternal and perinatal health globally. Maternal obesity is a known risk factor for HDP. This review sought to identify adiposity indicators in early pregnancy that are linked to the development of HDP.

METHODS

We conducted a systematic search of the PubMed, Science Citation Index (Web of Science), and Embase databases. Screening and quality evaluation of studies was conducted independently by two reviewers. Both random effects meta-analysis and narrative synthesis were performed.

RESULTS

Thirty-one studies were included with a pooled sample of 81,311 women. The meta-analysis showed that the odds of HDP were significantly increased by higher pregnancy measures of adiposity (pre-pregnancy body mass index (OR = 2.14, 95%CI: 1.67-2.75), visceral adipose tissue (OR = 1.79, 95%CI: 1.01-3.16), subcutaneous adiposity thickness (OR = 1.67, 95%CI: 1.36-2.05), waist circumference (OR = 2.20, 95%CI: 1.37-3.54), waist to-hip ratio (OR = 3.08, 95% CI: 1.38-6.87), weight gain (OR = 1.69, 95%CI: 1.42-2.02) and percentage body fat (OR = 1.71, 95%CI: 1.16-2.53)). Epicardial fat thickness was significantly associated with HDP, although limited data were available.

CONCLUSIONS

The results of our study highlight the importance of investigating the predictive value of adiposity measures in identifying the risk of HDP to tailor care towards women at the highest risk.

Association between maternal adiposity measures and adverse maternal outcomes of pregnancy: Systematic review and meta-analysis

Maternal obesity increases pregnancy-related risks. Women with a body mass index (BMI) ≥ 30 kg/m2 are considered to be at risk and should receive additional care, although approximately half will have uncomplicated pregnancies. This systematic review aimed to identify early pregnancy measures of adiposity associated with adverse maternal health outcomes. Searches included six databases, reference lists, citations, and contacting authors. Screening and quality assessment were carried out by two authors independently. Random effects meta-analysis and narrative synthesis were conducted. Seventy studies were included with a pooled sample of 89,588 women. Meta-analysis showed significantly increased odds of gestational diabetes mellitus (GDM) with higher waist circumference (WC) categories (1.40, 95% confidence interval [CI] 1.04, 1.88) and per unit increase in WC (1.31, 95% CI 1.03, 1.67). Women with GDM had higher WC than controls (mean difference [MD] 6.18 cm, 95% CI 3.92, 8.44). WC was significantly associated with hypertensive disorders, delivery-related outcomes, metabolic syndrome, and composite pregnancy outcomes. Waist to hip ratio was significantly associated with GDM, hypertensive disorders, and delivery-related outcomes. Fat mass, neck circumference, skinfolds, and visceral fat were significantly associated with adverse outcomes, although limited data were available. Our findings identify the need to explore how useful adiposity measures are at predicting risk in pregnancy, compared with BMI, to direct care to women with the greatest need.

Preeclampsia has two phenotypes which require different treatment strategies

The opinion on the mechanisms underlying the pathogenesis of preeclampsia still divides scientists and clinicians. This common complication of pregnancy has long been viewed as a disorder linked primarily to placental dysfunction, which is caused by abnormal trophoblast invasion, however, evidence from the previous two decades has triggered and supported a major shift in viewing preeclampsia as a condition that is caused by inherent maternal cardiovascular dysfunction, perhaps entirely independent of the placenta. In fact, abnormalities in the arterial and cardiac functions are evident from the early subclinical stages of preeclampsia and even before conception. Moving away from simply observing the peripheral blood pressure changes, studies on the central hemodynamics reveal two different mechanisms of cardiovascular dysfunction thought to be reflective of the early-onset and late-onset phenotypes of preeclampsia. More recent evidence identified that the underlying cardiovascular dysfunction in these phenotypes can be categorized according to the presence of coexisting fetal growth restriction instead of according to the gestational period at onset, the former being far more common at early gestational ages. The purpose of this review is to summarize the hemodynamic research observations for the two phenotypes of preeclampsia. We delineate the physiological hemodynamic changes that occur in normal pregnancy and those that are observed with the pathologic processes associated with preeclampsia. From this, we propose how the two phenotypes of preeclampsia could be managed to mitigate or redress the hemodynamic dysfunction, and we consider the implications for future research based on the current evidence. Maternal hemodynamic modifications throughout pregnancy can be recorded with simple-to-use, noninvasive devices in obstetrical settings, which require only basic training. This review includes a brief overview of the methodologies and techniques used to study hemodynamics and arterial function, specifically the noninvasive techniques that have been utilized in preeclampsia research.

Prevalence of hypertensive disorders in pregnancy in China: A systematic review and meta-analysis

Hypertensive disorders in pregnancy (HDP) are associated with various maternal and fetal adverse outcomes and become an increasingly significant threat to Chinese pregnant women. Yet, the prevalence of HDP in China is not clear. We conducted this meta-analysis to estimate the prevalence of HDP and specific subtypes in China. We searched PubMed, Embase, Web of Science, CNKI, Wangfang, and CMB for studies on prevalence of HDP and specific subtypes, published from 1990 to Jan 21, 2020, without language restrictions. We included all studies reported the prevalence of HDP and specific subtypes in Chinese pregnant women. We excluded qualitative studies, case reports, reviews, conference presentations, and studies only provided abstracts. We using a standard self-developed form to extract information from eligible studies. We did meta-analyses by random-effect models and estimated the pooled prevalence of HDP and specific subtypes. In order to explore potential sources of heterogeneity and subgroup effects, we did and meta-regression and subgroup analyses by pre-specified covariates. This study is registered with PROSPERO, number CRD42020166001. We initially identified 4179 records, of which 92 studies with 1,377,448 participants were eligible in the final systematic review and meta-analyses. The pooled prevalence (95% CI) of HDP, gestational hypertension, preeclampsia, mild preeclampsia, severe preeclampsia, eclampsia, chronic hypertension, and chronic hypertension with superimposed preeclampsia were 7.30% (6.60%-8.00%), 3.30% (2.90%-3.70%), 4.50% (4.00%-5.00%), 2.00% (1.70%-2.30%), 2.60% (2.10%-3.00%), 0.11% (0.08%-0.15%), 0.60% (0.30%-0.90%), and 0.60% (0.40%-0.80%), respectively. No publication bias was identified, although heterogeneity was high (I² statistics: 92.0%-99.3%). High prevalence of HDP and the subtypes frequently reported in Western and Northern China. Pregnant women who were aged 35 years and above had high prevalence of HDP and subtypes; women who were overweight or obese had high prevalence of HDP, gestational hypertension and preeclampsia. The prevalence of HDP and the subtypes vary in different areas in China. Given to increasingly prevalent of the risk factors, such as overweight, obesity, and advance maternal age, strategies to prevent and manage HDP need to be improved, especially for women living in Western and Northern China.