Maternal Vascular Indices, Biomarkers at 36 Week's Gestation Predict Preeclampsia, New Study Concludes

Among women who developed preeclampsia (PE), increased arterial stiffness and elevated central blood pressure at 35 to 37 weeks’ gestation were the vascular indices associated with the greatest predictive value for clinical onset of the hypertensive disorder of pregnancy, according to new research.

_{^{©Capifrutta/shutterstock.com}}

The most effective indices for prediction of subsequent PE were identified as maternal pulse wave velocity (PWV) in combination with mean arterial pressure (MAP) and uterine artery pulsatility index.

The findings, published in the American Journal of Obstetrics & Gynecology, suggest that a complex interaction between vascular abnormalities and biomarkers associated with pregnancy may play a significant role in the increased risk for postpartum cardiovascular morbidity observed among women with PE and that combinations of maternal risk factors and biophysical and biochemical marker could help identify risk.

Approximately 5% of pregnancies are affected by PE, making it the leading cause of maternal and perinatal morbidity and mortality, study authors wrote. PE is known to increase risk of hypertension by 4-fold and adverse cardiovascular events within a decade by 2-fold. These associations may potentially indicate accelerated vascular aging in women with PE, according to first author Tanvi Mansukhani, MD, of the Harris Birthright Research Centre for Fetal Medicine, King’s College, London, UK, and colleagues. However, data on vascular abnormalities and PE is lacking, a knowledge gap their study was designed to help fill.

Goals of the prospective observational study were to assess differences in vascular indices at 35 to 37 weeks’ gestation between women who subsequently developed PE and those who did not and to determine whether vascular measures are a useful predictive tool for development of PE.

Participants included women visiting King’s College Hospital, London, United Kingdom between December 2021, and April 2022, at 35 weeks to 36 weeks and 6 days’ gestation of a singleton pregnancy delivering a nonmalformed live-born or stillborn neonate.

Patient characteristics collected included ethnicity, weight, height, age, conception method, and history of chronic hypertension, diabetes mellitus, systemic lupus erythematosus, or antiphospholipid syndrome. Family PE and obstetrical history were also assessed.

At the visit, data were collected on maternal demographic characteristics, medical history, maternal vascular indices, and hemodynamic parameters for stroke volume, heart rate, cardiac output, central systolic blood pressure (SBP) and diastolic blood pressure (DBP), total peripheral resistance mean pulse wave velocity (PWV), and augmentation index (AIx).

Investigators used validated automated devices and standard protocol to determine mean arterial pressure (MAP) and uterine artery pulsatility index was measured using transabdominal ultrasound. Fetal crown-rump length at 11 to 13 weeks’ gestation or fetal head circumference at 19 to 24 weeks’ gestation was measured to determine gestational age.

Aortic stiffness was determined using a measure of carotid to femoral PWV. The brachial artery pulse waveform was also evaluated, allowing calculations of parameters including the central aortic SBP and DBP, stroke volume, total peripheral resistance, and cardiac output. The researchers also assessed serum concentration of placental growth factor (PIGF) and soluble fms-like tyrosine kinase-1 (sFLT-1).

Delivery with PE within 3 weeks following the study assessment was reported as the primary outcome. Pregnancy outcome data were also obtained from hospital maternity records or the records of patients’ general medical practitioners.

FINDINGS

The final cohort for analysis numbered 6746 women with singleton pregnancies, 2.6% of whom developed subsequent PE. Women with PE were more often Black and nulliparous, and more often had chronic hypertension, a family history of PE, or PE in a prior pregnancy. These women also had a higher average weight and body mass index, according to the study.

High discrimination. Among study participants with PE, Mansukhani and colleagues reported significantly increased cardiac output, total peripheral resistance, central SBP and DBP, PWV, stroke volume, and Aix vs those without PE, as well as significantly decreased heart rate. The “most discriminatory indices” were central SBP and DBP and PWV with the remaining indices having relatively poor predictive value.

Screening performance. When they compared screening performance by a combination of maternal risk factors (MRFs) plus MAP, the researchers found the performance of PE screening within 3 weeks of assessment and at any time was improved when utilizing MRFs plus MAP vs MRFs plus SBP and DBP. The detection rates (DRs) differed by 19.80% and 7.95%, respectively, suggesting MAP as a more favorable marker for PE prediction vs central SBP and DBP.

Screening using a combination of MRFs, MAP, PIGF and sFMS and sFLT-1led to the highest DR of 84.0% for PE within 3 weeks of assessment. The best prediction of PE at any time of assessment was a DR of 67% and was the result of combining MRFs with all 5 biomarkers.

These results indicated increased arterial stiffness and central SBP and DBP at 35 to 37 weeks’ gestation among women who develop subsequent PE vs normotensive women. Investigators concluded these factors alongside other biomarkers may be used to predict PE development.

Source: Mansukhani T, Wright A, Arechvo A, et al. Maternal vascular indices at 36 weeks’ gestation in the prediction of preeclampsia. Am J Obstet Gynecol. 2024;230:448.e1-15. doi:10.1016/j.ajog.2023.09.095