EP17.42: Association between mean arterial pressure and uterine artery pulsatility index >95th percentile in first trimester screening in singleton pregnancies

To determine whether there is an association between mean arterial blood pressure ≥ 100 mmHg and uterine artery pulsatility index >95th percentile (IPAUt >P95) in first trimester screening in singleton pregnancies. Cross-sectional study between 2018 and 2023 at two obstetric ultrasound centres. Ultrasounds were performed by experts in maternal fetal medicine and endorsed by the Fetal Medicine Foundation. Patients with first trimester screening and CRL < 84mm were included. The cutoff point for mean arterial blood pressure (MAP) was ≥ 100mmHG. The cutoff point for the 95th percentile was 2.42. Analysis was performed according to the nature of the variables. A Chi-square test was used to determine a possible association, considering p < 0.05 as significant. A total of 1899 patients were evaluated, of whom 1301 (68.5%) met the inclusion criteria. Mean maternal age was 33.5 ± 4.6 years, and gestational age was 12.0 ± 0.4 weeks. 93.9% of patients with MAP ≥ 100mmHg had IPAUt < P95, versus 6.1% with IPAUt > P95. No statistically significant association was found between MAP ≥ 100mmHg and IPAUt > P95. In our experience, a MAP ≥ 100mmHg has no association with IPAUt > P95. Considering that most of the patients with elevated mean arterial pressure values had an IPAUt below P95, we consider it important to take blood pressure as a complementary part of first trimester screening.