Abstract
Objective: Abnormal umbilical artery blood flow has been implicated in pregnancy complications and fetal demise. Its relation to histopathological changes in the placenta and to maternal or fetal thrombophilia is less well understood. The aim of this study was to evaluate the relation between umbilical artery Doppler findings, placental histopathology, and maternal and fetal coagulation factor V Leiden (FVL) status.
Methods: Two previous studies on FVL in pregnancy made the placentas of 25 women with maternal FVL carriership and 43 randomly selected non-carriers available for a histopathological examination. Umbilical artery Doppler velocimetry was performed on 54 women in late pregnancy.
Results: Abnormal umbilical artery Doppler velocimetry was associated with an approximately sevenfold increased risk of fetoplacental thrombotic vasculopathy (odds ratio [OR]: 7.5, 95% confidence intervals [CI]: 1.3–44.3), ischemic lesions (OR: 7.5, 95% CI: 1.2–46.1) and fetal carriership of FVL (OR: 8.2, 95% CI: 1.5–43.5), but not maternal FVL. Fetal FVL carriership was also associated with a sevenfold increased risk of ischemic lesions (OR: 6.7, 95% CI: 1.3–35).
Conclusions: Our results indicate that the fetal – not the maternal – FVL carriership matters regarding the umbilical artery blood flow and placental pathology, which might explain some of the heterogeneity of studies.