EP17.47: The effects of unilateral uterine artery notch detected at 24 weeks of gestation on perinatal outcomes in low‐risk pregnancies

Though bilateral uterine artery (UA) notch has repeatedly shown to be associated with secondarily insufficient trophoblast invasion of the spiral arteries, unilateral uterine artery notch has not been sufficiently studied. Previous studies have confirmed the association between increased blood flow resistance in both uterine arteries (bilateral UA notch) and a higher risk of placental syndromes. In this study, we aimed to assess the effects of unilateral UA notch detected at 24 gestational weeks on perinatal outcomes in low-risk pregnancies. This is a retrospective study comparing neonatal outcome between low risk pregnant women with unilateral UA notch detected at 24 weeks and women without notch. Outcome measures were birthweight, birth week, presence or absence of intrauterine growth retardation (IUGR), pre-eclampsia, preterm birth, and the mode of delivery, Ph, base deficit, APGAR scores, ICU admission rate. A total of 162 patients enrolled in the study, (n = 35) of which were detected with a unilateral UA notch (study) and (n = 127) patients with normal UA (control). The mean ages of the study and control groups were 26 (19–34) vs 29 (19–44), respectively (p= 0.001). Birthweights and mean z scores of birthweights were not different between groups [(3100gr (550- 3950) vs 3350gr (1680-4660gr), p= 0,008 and 0.31 ± 0.85 vs 0.10 ± 0.96, p = 0.259)], the prevalence of preterm birth was (14.3% vs 7.1% respectively p = 0.185) and pre-eclampsia was (2.9% vs 1.6% for notch and control groups, respectively p = 0.259), and the prevalence of neonatal ICU admission after birth was (14.3% vs 11.8% respectively p= 0.772), which were not remarkable. There was no correlation between IUGR and the unilateral UA notch. In logistic regression analysis, unilateral uterine artery notch was not found to be an independent risk factor for any of the observed postnatal outcome measures. Uterine artery notch at 24 weeks in low risk pregnancies is not associated with an increased risk of adverse pregnancy outcome.