AbstractObjectiveThe aim of this study was to compare position-related changes in fetal middle cerebral artery (MCA) Doppler pulsatility indices (PI).MethodsA prospective study of 41 women with conditions associated with placental-pathology (chronic hypertension, pregestational diabetes, and abnormal analytes) and 34 women without those conditions was carried out. Fetal MCA Doppler velocity flow waveforms were obtained in maternal supine and left lateral decubitus positions. MCA PI Δ was calculated by subtracting the PI in the supine position from the PI in the left lateral position. Secondary outcomes included a composite of adverse perinatal outcomes (fetal growth restriction, oligohydramnios, and preeclampsia). χ2 and Student t-tests and repeated-measures analysis of variance were used.ResultsMCA PI Δ was significantly less for high-risk pregnant women ([P = 0.03]: high risk, left lateral PI, 1.90 ± 0.45 vs. supine PI, 1.88 ± 0.46 [Δ = 0.02]; low risk, left lateral PI, 1.90 ± 0.525 vs. supine PI, 1.68 ± 0.40 [Δ = 0.22]). MCA PI Δ was not significantly different between women who had a composite adverse outcome and women who did not have a composite adverse outcome (P = 0.843).ConclusionOur preliminary study highlights differences in position-related changes in fetal MCA PI between high-risk and low-risk pregnancies. These differences could reflect an attenuated ability of women with certain risk factors to respond to physiologic stress.
Use of conditional centiles of middle cerebral artery pulsatility index and cerebroplacental ratio in the prediction of adverse perinatal outcomes
