Placenta Previa In Third Trimester Research Articles

Fate of second trimester low-lying placentae

Background: Placenta previa and low-lying placenta are potentially fatal conditions for both mother and child. The purpose of this work was to evaluate the cut-off level distance between lower edge of placenta and internal cervical os and whether it can predict third trimester placenta previa or not.Methods: This prospective observational work was carried out on 50 low- lying placenta cases with single living pregnancy with 18–24-week gestation. Patients were splitted into two groups: group 1 consists of 46 individuals; group 2 consists of 4 individuals. They were recruited from Obstetrics and Gynecology departments at Tanta University Hospitals and Kafr El–Sheikh General hospital.Results: Second-trimester internal os distance (IOD) associated significantly with placental position in the third trimester also when considering those with an anteriorly and posteriorly located placenta, IOD values of at least 5 mm for posteriorly and at least 2 mm for anterior located placenta had a likelihood ratio of 0.1 and 0 respectively in the prediction of an abnormally positioned placenta in the third trimester. All women with an IOD at or above these cut-off values can be reassured without follow-up that their final placental position will be normal. Regarding IOD; AUC was 0.937, 0.850 the sensitivity was 93%, 92% & the specificity was 57%, 64% Anterior and posterior respectively.Conclusions: IOD cut-off value of 5mm or less was highly sensitive in predicting placenta previa in third trimester.

Does cervical length and the lower placental edge thickness measurement correlates with clinical outcome in cases of complete placenta previa?

To evaluate the effectiveness of cervical length and the lower placental edge thickness measurement in predicting the risk of antepartum hemorrhage (APH) and emergency preterm cesarean delivery in women with complete placenta previa. Fifty-four cases with confirmed diagnosis of complete placenta previa in third-trimester were subjected to transvaginal sonographic measurement of cervical length and lower placental edge thickness and correlated this to clinical outcome with regards to gestational age at delivery, ante partum hemorrhage, emergency cesarean section before 36 weeks due to massive hemorrhage and neonatal birth weight. Antepartum bleeding and emergency cesarean section rate before 36 weeks due to massive bleeding were significantly higher in cases with thick lower placental edge or central placenta than cases with thin lower placental edge [16 cases (53.3%) vs. 5 cases (20.8%)] for the former and [14 cases (46.6%) vs. 4 cases (16.6%) for the later]. Antepartum bleeding was observed in 18 cases (51.4%) when cervical length measurements ≤30 mm of whom 16 cases (88.9%) had showed severe attack necessitated emergency cesarean delivery before 36 weeks versus 4 cases (21.1%) with cervical length ≥30 mm. By combining cervical length with lower placental edge thickness measurement sensitivity, specificity, positive predictive value (PPV) negative predictive value (NPV) and accuracy increased to 83.3, 78.4, 53.4, 79.8 and 89.7%, respectively for the prediction of antepartum bleeding and emergency cesarean section <36 weeks using receiver-operating characteristics curve with area under the curve 0.882. Short cervical length at cut-off value ≤30 mm and increased lower placental edge thickness measurements may predict with high accuracy the risk of APH and emergency preterm cesarean delivery in patients with complete placenta previa.