Relationship between Abnormal Placenta and Obstetric Outcomes: A Meta-Analysis

Abstract

The placenta has several crucial physiological functions that help maintain a normal pregnancy. Although approximately 2–4% of pregnancies are complicated by abnormal placentas, obstetric outcomes remain understudied. This study aimed to determine the outcomes and prevalence of patients with abnormal placentas by conducting a systematic review of 48 studies published between 1974 and 2022. The cumulative prevalence of circumvallate placenta, succenturiate placenta, multilobed placenta, and placenta membranacea were 1.2%, 1.0%, 0.2%, and 0.004%, respectively. Pregnancies with a circumvallate placenta were associated with an increased rate of emergent cesarean delivery, preterm birth (PTB), and placental abruption compared to those without a circumvallate placenta. The succenturiate lobe of the placenta was associated with a higher rate of emergent cesarean delivery, whereas comparative results were observed in terms of PTB, placental abruption, and placenta previa in comparison to those without a succenturiate lobe of the placenta. A comparator study that examined the outcomes of multilobed placentas found that this data is usually unavailable. Patient-level analysis (n = 15) showed high-rates of abortion (40%), placenta accreta spectrum (40%), and a low term delivery rate (13.3%) in women with placenta membranacea. Although the current evidence is insufficient to draw a robust conclusion, abnormal placentas should be recognized as a high-risk factor for adverse outcomes during pregnancy.

Succenturiate Placental Lobe Abruption

“…20 This data was also confirmed in a recent review from early 2023, were the authors concluded that succenturiate placenta may be a high-risk factor for emergency caesarean delivery and postpartum hemorrhage, whereas it may not be a risk factor for preterm birth, fetal growth restriction or placental abruption. 2 However, in our case, the patient presented to emergency room with abruptio placentae, in the absence of other risk factors such as preeclampsia, physical/psychological trauma or consumption of prohibited substances, with the placental 1044 anomaly as the only potential culprit. The histopathological report confirmed the rupture of placental vessels neighboring the aberrant placental lobe with the extension of the hematoma towards the main placental mass and its detachment.…”

“…Morphologic placental anomalies can be classified as: circumvallate placenta, succenturiate placenta, multilobed placenta (bilobed/bipartite/duplex placenta), placenta fenestrata, placenta membranacea, and ring-shaped placenta. 2 The succenturiate placenta is a morphological variation of the placenta that usually presents as a distinct lobe from the main placental disc, which can be single or multiple. It occurs in approximately 0.16% to 5% of pregnancies.…”

“…3 The most common complications of succenturiate placentas include fetal and maternal death, resulting from ruptured accessory vessels during uterine contractions causing hemorrhage and abruptio placentae, prematurity in the context of emergency caesarean section for acute fetal distress, 6 placental retention in the third stage of delivery and postpartum hemorrhage. 2 To ensure maternal-fetal safety and anticipate possible hemorrhagic complications that can threaten the life of the patient and fetus, it is crucial to make the correct antenatal diagnosis of vasa previa and to raise suspicion of a succenturiate lobe placenta. However, the prenatal ultrasound detection of this placental anomaly is not always handy.…”

Systematic Review of the Survival Outcomes of Neoadjuvant Chemotherapy in Women with Malignant Ovarian Germ Cell Tumors

“…The search keywords used to identify relevant studies are listed in Supplementary File S1 . MeSH terms were searched in the PubMed and Cochrane databases to identify articles on NACT use in women with MOGCT, as previously described [ 19 , 20 ].…”