A 34-year-old G6P5 presents to labor and delivery by ambulance at 33 weeks’ gestational age complaining of the sudden onset of profuse vaginal bleeding. The patient denies any abdominal pain or uterine contractions. She denies any problems with her pregnancy to date but has had no prenatal care. She admits to smoking several cigarettes a day, but denies any drug or alcohol use. The fetal heart rate tracing is normal. There are no contractions on the tocometer.
Match the descriptions with the appropriate placenta type.
A. Fenestrated placentaA placenta accreta occurs when the trophoblastic tissue invades the superficial lining of the uterus. In this instance, the placenta is abnormally adherent to the uterine wall and cannot be easily separated from it. A portion of the placenta may be removed, while other parts remain attached, resulting in hemorrhage. A succenturiate placenta is characterized by one or more smaller accessory lobes located in the membranes at a distance from the main placenta. A retained succenturiate lobe may cause uterine atony and result in postpartum hemorrhage. In placenta previa, the placenta is located very near or over the internal cervical os. Painless hemorrhage can occur without warning, and is caused by tearing of the placental attachments during formation of the lower uterine segment in the third trimester, or with cervical dilation during term or preterm labor. A history of previous cesarean delivery, grand multiparity, and maternal smoking have been associated with an increased risk of placenta previa. Vasa previa occurs when there is a velamentous insertion of the umbilical cord or a succenturiate lobe and the fetal vessels within the membranes traverse the internal cervical os. The fenestrated placenta is a rare anomaly where the central portion of the placenta is missing. In the membranous placenta, all fetal membranes are covered by villi, and the placenta develops as a thin membranous structure. This type of placenta is also known as placenta diffusa.