Timing of Histologic Progression from Chorio-Deciduitis to Chorio-Deciduo-Amnionitis in the Setting of Preterm Labor and Preterm Premature Rupture of Membranes with Sterile Amniotic Fluid

Placental histopathology in preterm birth with confirmed maternal infection: A systematic literature review

Four in five neonatal deaths of preterm births occur in low and middle income countries and placental histopathology examination can help clarify the pathogenesis. Infection is known to play a significant role in preterm birth. The aim of this systematic review is to explore the association between placental histopathological abnormality and preterm birth in the presence of confirmed infection. PubMed/Medline, Scopus, Web of Science and Embase were searched using the keywords related to preterm birth, placental histopathology and infection. Titles and abstracts were screened and the full texts of eligible articles were reviewed to extract and summarise data. Of 1529 articles, only 23 studies (13 bacterial, 6 viral and 4 parasitic) were included, and they used 7 different gestational age windows, and 20 different histopathological classification systems, precluding data pooling. Despite this, histopathological chorioamnionitis, and funisitis (when examined) were commonly observed in preterm birth complicated by confirmed bacterial or viral, but not parasitic, infection. The presence of malaria parasites but not pigment in placenta was reported to increase the risk of PTB, but this finding was inconclusive. One in three studies were conducted in low and middle income countries. An array of: definitions of preterm birth subgroups, histological classification systems, histopathologic abnormalities and diagnostic methods to identify infections were reported in this systematic review. Commitment to using standardised terminology and classification of histopathological abnormalities associated with infections is needed to identify causality and potential treatment of preterm birth. Studies on preterm birth needs to occur in high burden countries and control for clinical characteristics (maternal, fetal, labor, and placental) that may have an impact on placental histopathological abnormalities.

Identifying the associated factors with onset of preterm PROM compared with term PROM - A retrospective cross-sectional study

OBJECTIVE

To determine the risk factors associated with the preterm premature rupture of membranes (p-PROM).

MATERIALS AND METHODS

This retrospective cross-sectional study assessed 110 p-PROM cases from among 6642 deliveries at a Japanese perinatal medical center, from June 2016 to September 2018. The control group comprised 220 term PROM (t-PROM) cases. We excluded cases with artificial PROM or rupture of membranes after labor, those with multiple pregnancies, those with p-PROM at 36 weeks and those with t-PROM at 37 weeks. In order to compare p-PROM with t-PROM, univariate and multivariate analysis were performed using several clinical factors at the time of PROM onset.

RESULTS

The p-PROM group included 110 cases with 14-35 weeks PROM, and the t-PROM group included 220 cases with 38-41 weeks PROM. Eleven factors were identified as significant factors on the univariate analysis. A history of cervical conization (OR 37.5, 95% CI: 2.31-607.1), cervical length <25 mm at 28 weeks (OR 9.31, 95% CI: 1.76-49.3), negative Lactobacillus (OR 4.01, 95% CI: 1.18-13.7), and bleeding during the second trimester (OR 3.35, 95% CI: 1.18-9.53) were identified as significant factors by the multivariate analysis. Based on the risk factors identified during the multivariate analysis, we divided the 330 cases in the following three groups: 0 group (n = 244), 1 group (n = 60), and 2-4 group (n = 26). The ratio of p-PROM:t-PROM was calculated and compared for each group. The ratios were 21% (0 group), 57% (1 group), and 100% (2-4 group), indicating statistically significant differences between the groups (p < 0.001).

CONCLUSION

We found that the following four factors were associated with p-PROM: history of cervical conization, cervical length <25 mm at 28 weeks, negative Lactobacillus, and bleeding during the second trimester. Our results suggest that we can identify patients who are at increased risk for p-PROM, based on these factors. Further research is necessary to determine the optimal treatment approach for these patients to prevent p-PROM.