Placental Pathology Findings in Unexplained Pregnancy Losses.

There are approximately 5 million pregnancies per year in the USA, with 1 million ending in miscarriage (a loss occurring prior to 20 weeks of gestation) and over 20,000 ending in stillbirth at or beyond 20 weeks of gestation. As many as 50% of these losses are unexplained. Our objective was to evaluate the effect of expanding the placental pathology diagnostic categories to include the explicit categories of (1) dysmorphic chorionic villi and (2) small placenta in examining previously unexplained losses. Using a clinical database of 1256 previously unexplained losses at 6-43 weeks of gestation, the most prevalent abnormality associated with each loss was determined through examination of its placental pathology slides. Of 1256 cases analyzed from 922 patients, there were 878 (69.9%) miscarriages and 378 (30.1%) antepartum stillbirths. We determined the pathologic diagnoses for 1150/1256 (91.6%) of the entire series, 777/878 (88.5%) of the miscarriages (< 20 weeks' gestation), and 373/378 (98.7%) of the stillbirths (≥ 20 weeks' gestation). The most common pathologic feature observed in unexplained miscarriages was dysmorphic chorionic villi (757 cases; 86.2%), a marker associated with genetic abnormalities. The most common pathologic feature observed in unexplained stillbirths was a small placenta (128 cases; 33.9%). Our classification system reinforced the utility of placental examination for elucidating potential mechanisms behind pregnancy loss. The improved rate of diagnosis appeared to be the result of filling a gap in previous pregnancy loss classification systems via inclusion of the categories of dysmorphic chorionic villi and small placenta.

Maternal Outcomes in Subsequent Pregnancies After Classical Cesarean Delivery.

OBJECTIVE: To compare maternal outcomes in subsequent pregnancies of patients who had a prior classical cesarean delivery with those with a prior low transverse cesarean delivery. METHODS: We conducted a cross-sectional analysis of patients with live singleton births at or after 24 weeks of gestation who had a prior classical cesarean delivery or a low transverse cesarean delivery in the 2016-2019 National Inpatient Sample database. Outcome measures included mode of delivery, uterine rupture, and severe maternal morbidity (SMM), as defined by the Centers for Disease Control and Prevention. Maternal outcomes were compared using the χ2 test and the propensity score method, accounting for differences in patients' clinical risk factors. Multivariable regressions further assessed how patients' sociodemographic and hospital characteristics might influence the differences in maternal outcomes between the two groups. RESULTS: The sample included 1,671,249 patients: 25,540 with prior classical cesarean delivery and 1,645,709 with prior low transverse cesarean delivery. Cesarean delivery occurred in 95.5% of patients with prior classical cesarean compared with 91.3% of those with prior low transverse delivery (P<.001; propensity score method: odds ratio [OR] 0.99, 95% CI 0.85-1.16) and uterine rupture occurred in 1.1% and 0.3%, respectively (P<.001; propensity score method: OR 2.17, 95% CI 1.40-3.36). Among patients with prior classical cesarean delivery, uterine rupture occurred in 10.6% of those who underwent labor compared with 0.3% of those who did not (P<.001). Rates of SMM were 5.9% and 2.0% in the two groups, respectively (P<.001; propensity score method: OR 1.87, 95% CI 1.53-2.29). After adjustment of maternal sociodemographic and hospital characteristics, differences in the risk of uterine rupture and SMM between the two groups were attenuated but remained significant. CONCLUSION: Prior classical cesarean delivery was associated with a higher risk of uterine rupture and SMM in subsequent pregnancies, compared with prior low transverse cesarean delivery, even after accounting for patients' clinical, sociodemographic, and hospital characteristics.