Hemodynamic Complications in Pregnancy: Preeclampsia and Beyond

Male infants are at higher risk of neonatal mortality and severe morbidity

BACKGROUND

While a male infant is usually born with a higher birthweight than his female counterpart, he is more at risk of variety of adverse perinatal outcomes. Indeed, throughout life, females exhibit a marked survival advantage compared to males. The aetiology for such pertinent sex disparity remains unclear and is likely multifactorial.

AIMS

The aim of this study was to investigate obstetric and perinatal outcomes by infant sex from 28 weeks in a contemporary, large Australian birth cohort.

MATERIALS AND METHODS

A 14-year retrospective cohort study of 130 133 births over 28 weeks gestation from a single tertiary centre.

RESULTS

Male infants had overall higher rates of neonatal mortality (0.12% vs 0.06%, P < 0.001) and severe neonatal morbidity (12% vs 9.1%, P < 0.001) (adjusted odds ratio (aOR) 1.41, 95% CI 1.35-1.47). The odds of overall perinatal mortality (stillbirth and neonatal death) were higher for male infants (aOR 1.30, 95% CI 1.08-1.56). The difference in severe neonatal morbidity when stratified by gestational age at birth only remained significant from >35 weeks gestation. Regardless of infant sex, rates of neonatal mortality and morbidity were lowest at 39 weeks gestation. Rates of preterm birth and operative birth were also higher for male infants.

CONCLUSIONS

Our study demonstrates significant disparities in clinical outcomes by infant sex with males at a disadvantage to female infants.

Overexpression of facilitative glucose transporter-3 and membrane procoagulation in maternal platelets of preeclamptic pregnancy

BACKGROUND

Preeclampsia (PE) is a hypertensive disorder during pregnancy that results in significant adverse maternal and neonatal outcomes. Platelet activation is present in PE and contributes to the thrombo-hemorrhagic states of the disorder. However, the mechanisms that initiate and/or sustain platelet activation in PE are ill-defined.

OBJECTIVES

We aimed to characterise this mechanism and the procoagulant potentials of platelets in PE.

METHODS

In this quantitative observational study, we analyzed platelet procoagulant membrane dynamics in patients with PE (n = 21) compared with age-matched normotensive pregnancies (n = 20), gestational hypertension (n = 10), and non-pregnant female controls (n = 19). We analyzed fluorescently labeled indicators of platelet activation, bioenergetics, and procoagulation (phosphatidylserine exposure and thrombin generation), coupled with high-resolution imaging and thrombelastography. We then validated our findings using flow cytometry, immunoassays, classical pharmacology, and convolutional neural network analysis.

RESULTS

PE platelets showed significant ultra-structural remodeling, are more extensively preactivated than in healthy pregnancies and can circulate as microaggregates. Preactivated platelets of PE externalized phosphatidylserine and thrombin formed on the platelet membranes. Platelets' expression of facilitative glucose transporter-1 increased in all pregnant groups. However, PE platelets additionally overexpress glucose transporter-3 to enhance glucose uptake and sustain activation and secretion events. Although preeclampsia platelets exposed to subendothelial collagen showed incremental activation, the absolute hemostatic response to collagen was diminished, and likely contributed to greater blood loss perioperatively.

CONCLUSIONS

We revealed 2 bioenergetic mediators in the mechanism of sustained platelet procoagulation in preeclampsia. Although glucose transporter-1 and glucose transporter-3 remain elusive antiprocoagulant targets, they may be sensitive monitors of PE onset and progression.

A Pilot Study of Dietetic, Phenotypic, and Genotypic Features Influencing Hypertensive Disorders of Pregnancy in Women with Pregestational Diabetes Mellitus

Hypertensive disorders of pregnancy (HDP) are a leading cause of maternal and perinatal morbimortality. Dietetic, phenotypic, and genotypic factors influencing HDP were analyzed during a nutrigenetic trial in Rio de Janeiro, Brazil (2016-2020). Pregnant women with pregestational diabetes mellitus (n = 70) were randomly assigned to a traditional or DASH diet group. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured during prenatal visits and HDP were diagnosed using international criteria. Phenotypic data were obtained from medical records and personal interviews. Genotyping for FTO and ADRB2 polymorphisms used RT-PCR. Linear mixed-effect models and time-to-event analyses were performed. The variables with significant effect on the risk for progression to HDP were: black skin color (adjusted hazard ratio [aHR] 8.63, p = 0.01), preeclampsia in previous pregnancy (aHR 11.66, p < 0.01), SBP ≥ 114 mmHg in the third trimester (aHR 5.56, p 0.04), DBP ≥ 70 mmHg in the first trimester (aHR 70.15, p = 0.03), mean blood pressure > 100 mmHg (aHR 18.42, p = 0.03), and HbA1c ≥ 6.41% in the third trimester (aHR 4.76, p = 0.03). Dietetic and genotypic features had no significant effect on the outcome, although there was limited statistical power to test both.

Placenta-derived proteins across gestation in healthy pregnancies-a novel approach to assess placental function?

BACKGROUND

Placenta-derived proteins in the systemic maternal circulation are suggested as potential biomarkers for placental function. However, the identity and longitudinal patterns of such proteins are largely unknown due to the inaccessibility of the human placenta and limitations in assay technologies. We aimed to identify proteins derived from and taken up by the placenta in the maternal circulation. Furthermore, we aimed to describe the longitudinal patterns across gestation of placenta-derived proteins as well as identify placenta-derived proteins that can serve as reference curves for placental function.

METHODS

We analyzed proteins in plasma samples collected in two cohorts using the Somalogic 5000-plex platform. Antecubital vein samples were collected at three time points (gestational weeks 14-16, 22-24, and 30-32) across gestation in 70 healthy pregnancies in the longitudinal STORK cohort. In the cross sectional 4-vessel cohort, blood samples were collected simultaneously from the maternal antecubital vein (AV), radial artery (RA), and uterine vein (UV) during cesarean section in 75 healthy pregnancies. Placenta-derived proteins and proteins taken up by the placenta were identified using venoarterial differences (UV-RA). Placenta-derived proteins were defined as placenta-specific by comparison to the venoarterial difference in the antecubital vein-radial artery (AV-RA). These proteins were described longitudinally based on the STORK cohort samples using a linear mixed effects model per protein. Using a machine learning algorithm, we identified placenta-derived proteins that could predict gestational age, meaning that they closely tracked gestation, and were potential read-outs of placental function.

RESULTS

Among the nearly 5000 measured proteins, we identified 256 placenta-derived proteins and 101 proteins taken up by the placenta (FDR < 0.05). Among the 256 placenta-derived proteins released to maternal circulation, 101 proteins were defined as placenta-specific. These proteins formed two clusters with distinct developmental patterns across gestation. We identified five placenta-derived proteins that closely tracked gestational age when measured in the systemic maternal circulation, termed a "placental proteomic clock."

CONCLUSIONS

Together, these data may serve as a first step towards a reference for the healthy placenta-derived proteome that can be measured in the systemic maternal circulation and potentially serve as biomarkers of placental function. The "placental proteomic clock" represents a novel concept that warrants further investigation. Deviations in the proteomic pattern across gestation of such proteomic clock proteins may serve as an indication of placental dysfunction.

Prevalence and outcomes of hypertension in pregnancy in non-metropolitan and metropolitan communities

OBJECTIVES

Hypertension during pregnancy is a leading cause of birthing parent mortality and adverse pregnancy outcomes. Since non-metropolitan communities face higher rates of several risk factors for hypertension in pregnancy and shortages in obstetrical services, persons residing in non-metropolitan areas may be at increased risk for adverse events compared to those living in metropolitan areas. Our study objectives were to examine by non-metropolitan vs. metropolitan birthing parent residence (1) the prevalence of chronic hypertension (cHTN) and hypertensive disorders of pregnancy (HDP), and (2) the prevalence of cesarean delivery, preterm birth, low birth weight, APGAR <7 at 5 min, NICU admission, and stillbirth/neonatal death among the group of birthing parents with cHTN and among the group of birthing parents with HDP.

METHODS

Using U.S. Natality data from 2016 to 2018, we described the prevalence of cHTN and HDP and the association of each with several birthing parent and neonatal outcomes, stratified by non-metropolitan versus metropolitan county of birthing parent residence. Multivariable Poisson regression models were used to calculate adjusted prevalence ratios for these adverse outcomes.

RESULTS

The prevalence of cHTN among pregnant individuals was 2.2% in non-metropolitan areas and 1.8% in metropolitan areas. For HDP, the prevalence was 7.4% in non-metropolitan areas and 6.6% in metropolitan areas. After adjusting for several sociodemographic characteristics among those with HDP, the prevalence ratio for an APGAR score < 7 at 5 min (aPR 1.34, 95% CI 1.29-1.38) and stillbirth/neonatal death (aPR 1.36, 95% CI 1.15-1.62) was increased among offspring born to birthing parents who resided in non-metropolitan counties. Similar results were seen among those with cHTN.

CONCLUSIONS

The prevalence of cHTN and HDP is elevated among birthing parents residing in non-metropolitan areas. Also, the prevalence of APGAR <7 and stillbirth//neonatal death following pregnancies complicated by hypertension were higher among neonates born to birthing parents residing in non-metropolitan areas. Further research should investigate the robustness of these findings using alternate definitions of rural and urban areas and the possible link between low APGAR score, low NICU admission, and stillbirth/neonatal death among birthing parents residing in non-metropolitan counties.