This thick ring of membranes is composed of a double fold of amnion and chorion with degenerated decidua vera and fibrin in between. Blood vessels, supplying nutrients and carrying waste products to and from the developing fetus, radiate from the umbilical cord insertion to as far as the ring of membranes, and then disappears from view. Signs & Symptoms
A circumvallate placenta does not always induce associated symptoms during pregnancy, making it extremely difficult to diagnose a circumvallate placenta in asymptomatic mothers. In symptomatic mothers, physicians may be able to detect a circumvallate placenta based on the presentation of the following signs. Vaginal bleeding: A circumvallate placenta can increase the risk of frequent vaginal bleeding during the first trimester of pregnancy. In a study conducted with 92 women with a circumvallate placenta, it was concluded that incidences of vaginal bleeding were significantly higher in women with a circumvallate placenta during all three trimesters when compared to the control group. However, a noted limitation of the study considered by the researchers was that because the study included such a small number of women, the obtained results may not be fully representative of the general population. Because the chorionic plate is much smaller than the basal plate in a circumvallate placenta, vaginal bleeding tends to occur at this site where the placenta is exposed and uncovered. In mothers presenting with vaginal bleeding, circumvallate placenta should be suspected as a possible cause of the vaginal bleeding.
Hypertensive disorders, like hypertension, have been found to affect about 10% of pregnancies in the United States and have resulted in about 6.8% of maternal deaths from 2011 to 2015. High blood pressure during pregnancy can potentially damage maternal organ systems such as the liver or the kidneys, which can be life-threatening. To prevent preeclampsia or eclampsia from developing in pregnancy, women with hypertension can be prescribed anti-hypertensive medications during pregnancy and are advised to monitor their blood pressure throughout the course of pregnancy. Maternal age
Another risk factor for developing any pregnancy complications is maternal age. Advanced maternal age, considered to be when a woman enters pregnancy at age 35 or above, has also been linked to increased risk of maternal mortality, preeclampsia, restricted fetal growth, fetal distress, and a variety of other pregnancy complications. Conversely, teenage pregnancy is also associated with increased risk of endometriosis, postpartum hemorrhage, and mild preeclampsia, when compared with pregnant mothers in their 20s. Genetically, the long period of time between meiotic arrest of the egg gamete as a fetus and each ovulation cycle occurring after the onset of female puberty in teenage years can potentially contribute to the increased risk for pregnancy complications in mothers who are age 35 or older at time of pregnancy. Substance use
Further, yet another factor inducing adverse complications in pregnancy is substance use status. Nicotine, alcohol, and marijuana are the most common substances used during pregnancies. Substance use in pregnancy is concerning because of its alarming association with other risk factors, such as mental illness.