Fetal sex is known to affect pregnancy outcomes. In current clinical practice, monitoring of fetal well-being is based on Doppler ultrasound measurements of major placental and fetal vessels. The objective of this study was to investigate the effect of fetal sex on Doppler parameters throughout gestation in healthy pregnancy. A prospective study was conducted in 240 pregnant women with ultrasound examinations at a 4-weekly interval between 12 and 38 weeks of gestation. Pulsed Doppler spectra were collected for the umbilical arteries (UAs), middle cerebral artery (MCA), descending abdominal aorta (DAo), and ductus venosus (DV). Linear mixed effects models were used to determine if the pulsatility indices (PIs) of these vessels depended on gestational age and fetal sex. While there were no differences in the MCA PI and DV PIV over gestation between female and male fetuses, the trajectory of the UA and DAo PIs differed by fetal sex (p = 0.02 and p = 0.01, respectively). Doppler ultrasound parameters were found to be dependent on fetal sex for some vessels and not for others in healthy pregnancies. Further investigations are needed to understand the physiological mechanisms for these sex differences and the relevance for disease processes in pregnancy.

中文翻译：

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妊娠期间胎儿多普勒参数的性别差异


众所周知，胎儿性别会影响妊娠结局。在当前的临床实践中，胎儿健康状况的监测基于主要胎盘和胎儿血管的多普勒超声测量。本研究的目的是调查健康妊娠期间胎儿性别对整个妊娠期多普勒参数的影响。对 240 名孕妇进行了一项前瞻性研究，她们在妊娠 12 周至 38 周之间每 4 周进行一次超声检查。收集脐动脉（UAs）、大脑中动脉（MCA）、腹降主动脉（DAo）和静脉导管（DV）的脉冲多普勒频谱。使用线性混合效应模型来确定这些血管的搏动指数（PI）是否取决于胎龄和胎儿性别。虽然女性和男性胎儿在妊娠期间的 MCA PI 和 DV PIV 没有差异，但 UA 和 DAo PI 的轨迹因胎儿性别而异（分别为 p = 0.02 和 p = 0.01）。发现多普勒超声参数对于某些血管而言取决于胎儿性别，而对于健康妊娠中的其他血管则不依赖于胎儿性别。需要进一步的研究来了解这些性别差异的生理机制以及与妊娠期疾病过程的相关性。