# Comparison of Utero-Placental Perfusion Development From First to Second Trimester Between Low-Risk and High-Risk Pre-eclampsia Groups With Aspirin Prophylaxis

## TL;DR

This study compares uteroplacental perfusion and fetal growth between high-risk and low-risk pre-eclampsia groups using aspirin prophylaxis from the first to second trimester.

## Contribution

The study identifies specific maternal and fetal biomarkers associated with pre-eclampsia risk in aspirin-treated high-risk pregnancies.

## Key findings

- Higher UtAPI MoM and persistent notching in the second trimester are linked to increased pre-eclampsia risk.
- Women with pre-existing hypertension show a significant decline in UtAPI development.
- Estimated fetal weight is significantly lower in the high-risk group compared to the control group.

## Abstract

Introduction

Pre-eclampsia (PE) is a common diagnosis in pregnancy and affects pregnancies worldwide. Early-onset PE often leads to severe maternal and fetal complications. Prophylactic use of aspirin (150 mg/day) before the 16th week of pregnancy can reduce the risk of PE. This study aimed to investigate the effects of maternal factors on the development of uteroplacental perfusion and fetal biometry from the first to the second trimester in a risk group receiving aspirin prophylaxis compared to a control group without Aspirin.

Methods

This case-control study included 448 women at high risk for PE (risk group, RG) receiving aspirin prophylaxis and 468 women at low PE risk without aspirin intake (control group, CG). Parameters recorded and considered in the first (T1) and second (T2) trimesters included uterine artery pulsatility multiple of the median (UtAPI MoM), notching at T1 and T2 and fetal biometry parameters at T2. Maternal factors were also captured, and their respective effects were examined.

Results

UtAPI MoM at T1 and T2 showed a significant positive correlation (r = 0.39, p < 0.001), with UtAPI MoM at T2 significantly higher for notching "yes" at T1. Pre-existing arterial hypertension and UtAPI development demonstrated a significant association (p = 0.006). Women without this risk factor showed a significantly (p < 0.001) greater decline in UtAPI development. The likelihood of notching "yes" at T2 (p < 0.001; OR: 5.80) was increased with higher UtAPI MoM at T1. The mean values (T1 and T2) of UtAPI MoM were significantly higher in the risk group than in the control group. Patients in the risk group exhibited notching at T2 (p < 0.001; OR: 5.64) more often compared to the control group. The 95% CI of the estimated fetal weight for notching "yes" at T1 was below the 50th percentile. Gestational age and head circumference/abdomen circumference (HC/AC) ratio showed a significant negative correlation (p < 0.001; b = -0.01). The control group showed significantly higher estimated fetal weights than the risk group. The HC/AC ratio in the risk group was above the HC/AC ratio in the control group but without proving significance.

Conclusions

Persistent notching and elevated UtAPI MoM levels in the second trimester may be risk factors for early-onset PE. Women with pre-existing arterial hypertension, notching and elevated UtAPI MoM values ​​in the first and second trimesters require special monitoring during the course of pregnancy.