RESUMEN
A 35-year-old woman (gravida 1, para 0) was admitted to our hospital at 28 weeks' gestation with vaginal bleeding from placenta previa. Severe fetal bradycardia was observed during fetal heart rate monitoring. Ultrasonography showed widely dilated veins on the fetal surface of the placenta and an extraordinarily low umbilical artery peak systolic velocity in the Doppler study. Umbilical cord torsion was suspected. On the subsequent day, we performed a cesarean section due to worsening fetal heart rate patterns. Umbilical artery blood gas analysis indicated severe acidemia (pH 7.063), and umbilical cord torsion was confirmed at the placental cord insertion site. Diagnosing UCT prenatally is challenging; however, it can be suspected by scanning for the widely dilated veins on the fetal placental surface, termed as the "Sunset Sign," an abnormally low umbilical artery peak systolic velocity, and other fetal Doppler abnormalities.
RESUMEN
Background: One of the major risks of preterm birth is a history of conization. However, the risk of infection due to this procedure is still not well known. Using next-generation sequencing, we aimed to reveal the influence of conization on vaginal microbiota in the following pregnancy, and their relationship between spontaneous preterm birth (sPTB). Methods: We conducted a prospective cohort study including 133 pregnant patients, of whom 25 had conization histories and 108 did not. Vaginal microbiome samples were collected using swabs by an obstetrician upon inclusion in the first trimester and during delivery. V1-V2 of the 16S rRNA gene were amplified and analyzed to identify the bacteria. Results: The conization group had a significantly lower delivery week (34 weeks vs. 36 weeks, p = 0.003) and higher sPTB rate (64% vs. 8.3%, p ≤ 0.001) than the control group. In the conization group, alpha (Chao 1, p = 0.02; phylogenetic diversity whole tree, p = 0.04) and beta diversity (permutational multivariate analysis of variance test, p = 0.04) of the vaginal microbiota was significantly higher during delivery in patients who delivered preterm than in those who delivered term. Community-state type IV in the first trimester was significantly associated with sPTB (overall odds ratio 3.80, 95% confidence interval 1.33-10.8, p = 0.01). Conclusions: Conization is a risk factor for sPTB. Increased risk of sPTB in patients after conization may belong to the vulnerable defense mechanism, due to the shortened cervix and decreased cervical mucus.
