Final answer:
Uteroplacental insufficiency leading to late decelerations is mainly caused by problems with the placenta, which fail to supply the fetus with necessary oxygen and nutrients, and it can be aggravated by factors like maternal hypertension, drug abuse, low amniotic fluid, or placental defects.
Step-by-step explanation:
Common causes of Uteroplacental Insufficiency leading to frequent and recurrent Late Decelerations often involve a problem with the placenta that stops it from providing adequate oxygen and nutrients to the fetus, potentially causing intrauterine growth restriction (IUGR). Late decelerations in fetal heart rate can result from severe uterine contractions that are too powerful or extended, preventing the restoration of oxygenated blood to the fetus. The examination of the expelled placenta is crucial to ensure no fragments remain that could cause postpartum hemorrhage.
Factors contributing to uteroplacental insufficiency include maternal hypertension, which can impair blood flow to the placenta, and conditions like preeclampsia. In addition, maternal lifestyle factors like drug abuse (tobacco or cocaine), insufficient amniotic fluid, and placental abnormalities can lead to oxygen deprivation in the fetus. The presence of meconium in the amniotic fluid often signals fetal hypoxia, which can also contribute to uteroplacental insufficiency.