Final answer:
Placenta previa, which occurs when the placenta covers the cervix partially or completely, is the primary fetal-related complication in pregnancy. This condition, occurring in about 0.5% of pregnancies, can lead to significant complications such as antepartum hemorrhage.
Step-by-step explanation:
Placenta Previa as a Primary Complication in Pregnancy
The primary complication of pregnancy in relation to the fetus is placenta previa. This condition occurs when the placenta has a low placement in the uterus, causing it to partially or completely cover the opening of the cervix as the fetus grows. It is the leading cause of antepartum hemorrhage, which is profuse vaginal bleeding after week 24 of pregnancy but prior to childbirth. Placenta previa can create significant risks during pregnancy and delivery, necessitating careful monitoring and management by healthcare providers.
Placenta previa typically arises when an embryo implants close to the internal os of the uterus, rather than the more optimal location at the fundus or posterior wall. The occurrence of placenta previa is relatively rare, affecting only about 0.5 percent of pregnancies. Nonetheless, it is a serious condition that can lead to significant maternal and fetal complications.
Placentation, which is the formation of the placenta, is usually complete by weeks 14-16 of pregnancy. The placenta plays a crucial role in fetal development by facilitating the exchange of nutrients and oxygen from the mother to the fetus, among other functions. If its placement is compromised, such as in placenta previa, it can affect both the mother's and baby's health and well-being.