Cesarean section per se is not a risk factor for non-anatomical placenta creta.

OBJECTIVE: To investigate whether mild forms of placenta creta (MPC) are more common in placentas delivered by cesarean section for non-anatomical indications than in placentas from vaginal deliveries. METHODS: This is a retrospective clinical study in which MPC was diagnosed histologically by the presence of myometrial fibers in the decidua basalis or parietalis or in direct contact with the Rohr fibrinoid or chorionic villi. After excluding 111 cases at high risk for anatomical PC, placentas from 830 consecutive cesarean deliveries (group 1) were retrospectively statistically compared with 907 placentas from vaginal deliveries (group 2). RESULTS: Statistically significant differences were found in six independent clinical and seven placental phenotypes. More frequently, pre-eclampsia, abnormal fetal heart rate tracing and umbilical artery Dopplers, hypercoiled umbilical cord, diffuse postuterine pattern of chronic hypoxic placental injury, and clusters of avascular or mineralized chorionic villi were found in group 1, while preterm delivery, induction of labor, and histological patterns related to stillbirth were observed in group 2. CONCLUSION: MPC diagnosed in placentas from cesarean sections performed for non-anatomical indications is not statistically significantly more common than in those after vaginal delivery. Therefore, MPC may feature similar diagnostic correlations and portend a similar prognosis for future pregnancies.

Basal Plate Myometrial Fibers and Hypertensive Disorders of Pregnancy: A Case-Control Study.

Introduction Basal plate myometrium (BPMYO), the pathological presence of myometrial fibers in the basal plate, is a common finding on pathological examination of the placenta, yet its clinical correlates are not well studied. As myometrial fibers are frequently located in proximity to poorly converted maternal spiral arteries, our objective was to determine whether BPMYO is associated with hypertensive disorders of pregnancy (HDP), a well-known clinical sequela of abnormal maternal artery remodeling. Methods This case-control study included women who delivered a live-born singleton gestation whose placentas were sent for pathological examination. Cases were women with HDP (gestational hypertension, preeclampsia, or HELLP syndrome) as defined by American College of Obstetricians and Gynecologists. Controls were women without HDP. Women with chronic hypertension were excluded. The primary outcome was the presence of BPMYO. Secondary outcomes included the pathologic stage of BPMYO and the incidence of pathologically defined accreta. Each outcome was compared between cases and controls in bivariable and multivariable analyses. Results Of the 306 women who met inclusion criteria, 230 (75%) had HDP. BPMYO was present in 99 (32%) of placentas. Compared to controls, cases were younger, had higher body mass index, and were more likely to have diabetes, be nulliparous, deliver preterm, and have had a prior cesarean. There were no differences in the incidence of BPMYO, stage of BPMYO, or incidence of pathologically defined accreta between cases and controls. These findings persisted after controlling for potential confounders. Conclusions Although BPMYO may be more common in the setting of abnormal placental vasculature, there is no significant association between BPMYO and HDP.