Ultrasonographic placental localization with respect to fetal position in utero

Focal increta placentomegaly of the posterior nonscarred uterine wall and posterior asynclitic presentation

BACKGROUND

Fetal malpresentations and malpositions are more common in placenta previa and uterine cavity abnormalities.

AIM

To show successful management of focal increta placentomegaly and uterine preservation in primiparous woman.

CASE REPORT

We describe posterior low-lying focal increta placentomegaly verified during cesarean section, which is a possible risk factor for persistent posterior asynclitism and consequent mechanical dystocia. In addition to antifibrinolytics and uterotonics, hemostatic compression sutures of the posterior uterine wall were performed with an applied intrauterine balloon, and thus the uterus was preserved in primiparous woman as a definitive therapy.

CONCLUSION

Timely identified malplacentation as well as adequate medical and surgical measures taken by an experienced team of obstetricians and anesthesiologists can contribute to preservation of the uterus and thus the life of mother and neonate.

Prediction of Preeclampsia and Intrauterine Growth Restriction: Development of Machine Learning Models on a Prospective Cohort

BACKGROUND

Preeclampsia and intrauterine growth restriction are placental dysfunction-related disorders (PDDs) that require a referral decision be made within a certain time period. An appropriate prediction model should be developed for these diseases. However, previous models did not demonstrate robust performances and/or they were developed from datasets with highly imbalanced classes.

OBJECTIVE

In this study, we developed a predictive model of PDDs by machine learning that uses features at 24-37 weeks' gestation, including maternal characteristics, uterine artery (UtA) Doppler measures, soluble fms-like tyrosine kinase receptor-1 (sFlt-1), and placental growth factor (PlGF).

METHODS

A public dataset was taken from a prospective cohort study that included pregnant women with PDDs (66/95, 69%) and a control group (29/95, 31%). Preliminary selection of features was based on a statistical analysis using SAS 9.4 (SAS Institute). We used Weka (Waikato Environment for Knowledge Analysis) 3.8.3 (The University of Waikato, Hamilton, NZ) to automatically select the best model using its optimization algorithm. We also manually selected the best of 23 white-box models. Models, including those from recent studies, were also compared by interval estimation of evaluation metrics. We used the Matthew correlation coefficient (MCC) as the main metric. It is not overoptimistic to evaluate the performance of a prediction model developed from a dataset with a class imbalance. Repeated 10-fold cross-validation was applied.

RESULTS

The classification via regression model was chosen as the best model. Our model had a robust MCC (.93, 95% CI .87-1.00, vs .64, 95% CI .57-.71) and specificity (100%, 95% CI 100-100, vs 90%, 95% CI 90-90) compared to each metric of the best models from recent studies. The sensitivity of this model was not inferior (95%, 95% CI 91-100, vs 100%, 95% CI 92-100). The area under the receiver operating characteristic curve was also competitive (0.970, 95% CI 0.966-0.974, vs 0.987, 95% CI 0.980-0.994). Features in the best model were maternal weight, BMI, pulsatility index of the UtA, sFlt-1, and PlGF. The most important feature was the sFlt-1/PlGF ratio. This model used an M5P algorithm consisting of a decision tree and four linear models with different thresholds. Our study was also better than the best ones among recent studies in terms of the class balance and the size of the case class (66/95, 69%, vs 27/239, 11.3%).

CONCLUSIONS

Our model had a robust predictive performance. It was also developed to deal with the problem of a class imbalance. In the context of clinical management, this model may improve maternal mortality and neonatal morbidity and reduce health care costs.

Anterior placental location influences onset and progress of labor and postpartum outcome

INTRODUCTION

The aim of the study is to evaluate whether placental location at term is associated with delivery outcome.

METHODS

A prospective study including 2354 patients with singleton pregnancy at term admitted for vaginal delivery was conducted. Placental position was determined before delivery by ultrasonographic examination performed transabdominally with women in the supine position. Maternal characteristics and delivery outcome such as premature rupture of membranes, induction of labor, mode and gestational age at delivery, indication for cesarean section, duration of the third stage, postpartum hemorrhage (PPH) and manual removal of placenta were correlated with anterior, posterior or fundal placental locations.

RESULTS

Among women enrolled: i) 1164 had an anterior placenta, ii) 1087 a posterior placenta, iii) 103 a fundal placenta. Women with anterior placenta showed: i) a higher incidence of induction of labor (p = 0.0001), especially for postdate pregnancies and prolonged prelabor rupture of membranes (p < 0.0001), ii) a higher rate of cesarean section rate for failure to progress in labor (p = 0.02), iii) a prolonged third stage (p = 0.01), iv) a higher incidence of manual removal of placenta (p = 0.003) and a higher rate of PPH in vaginal deliveries (p = 0.02).

DISCUSSION

The present study showed the influence of anterior placental location on the course of labor, with a later onset of labor, a higher rate of induction and cesarean section and postpartum complications. The reason for this influence on labor and delivery complications remains to be elucidated.

Placental location and pregnancy outcome

OBJECTIVE

The purpose of this study was to determine if placental location is associated with adverse pregnancy outcome and to assess whether any association exists between different blood groups and location of the placenta.

MATERIAL AND METHODS

Medical records of women were reviewed retrospectively and placental position as documented in the case notes at routine antenatal (20-38 weeks) ultrasonography was identified. Placental position was categorised as anterior, posterior and fundal. Association of placental location with foeto-maternal outcome and different blood groups was noted.

RESULTS

A total 474 case notes of women were analysed for placental location, feto-maternal outcome and blood groups. Anterior placenta was found to have a relation with a greater risk of pregnancy-induced hypertension, gestational diabetes mellitus and placental abruption (p<0.001), while posterior placenta had a significant association with preterm labour (p<0.001). Regarding foetal outcome, an anterior placenta was significantly associated with intrauterine growth retardation and intrauterine foetal death (p<0.001). The majority (54%) of women with an anterior placenta were O-positive blood group, while 46% of women in the posterior placenta group were A-positive blood group (p<0.001).

CONCLUSION

Anterior placental implantation is associated with an increased risk of pregnancy-induced hypertension, gestational diabetes mellitus, placental abruption, intrauterine growth retardation and intrauterine foetal death. Posterior placenta has a significant association with preterm labour and A-positive blood group. Anterior placenta is common in women with O-positive blood group. Placental location may be an important determinant of pregnancy outcome.

Intrauterine growth restriction and placental location

OBJECTIVE

The purpose of this study was to determine whether an association exists between intrauterine growth restriction (IUGR) and second-trimester placental location.

METHODS

A case-control study was performed in well-dated singleton pregnancies with (n = 67) and without (n = 205) IUGR (defined as estimated fetal weight <10th percentile for gestational age at the last sonographic examination) to investigate the association between IUGR and placental location. Placental location was determined by sonography at 16 to 20 weeks' gestation. Maternal, perinatal, and delivery characteristics were abstracted from medical records. Group comparisons were made by the Student t test, chi(2) analysis, the Fisher exact test, the Wilcoxon test, and analysis of variance. Multivariable logistic regression analysis was used to determine the relationship between IUGR and placental location.

RESULTS

In both groups, the most common placental locations in the second trimester were anterior and posterior. After adjusting for potential confounders (including race, chronic hypertension, and hypertensive disorders of pregnancy), IUGR pregnancies were nearly 4-fold more likely to have lateral placentation (odds ratio, 3.8; 95% confidence interval, 1.3-11.2) compared with anterior or posterior placentation.

CONCLUSIONS

Pregnancies complicated by IUGR are significantly more likely than non-IUGR pregnancies to have lateral placentation in the second trimester.

Obstetric antecedents of surgically treated obstetric brachial plexus injuries

OBJECTIVE

To determine whether the anatomy of an obstetric brachial plexus lesion (OBPL) is causally related to the preceding obstetric history.

DESIGN

Anatomical classification of the OBPL during reconstructive neurosurgical treatment in consecutive infants who had surgery for OBPL between 1986 and 1994 and relating these findings with the characteristics of the preceding birth.

SETTING

De Wever Hospital, Heerlen, The Netherlands.

SUBJECTS

All infants who had surgical treatment for OBPL between 1 April 1986 and 1 January 1994 (n = 130).

RESULTS

An Erb's C5-C6 injury was preceded more frequently by a difficult breech birth (19/26 cases or 73%). In contrast, the more extensive forms of Erb's palsy classified as a C5-C7 injury or a total palsy with a C5-T1 injury were observed more frequently after complicated cephalic birth (52/59 or 88%, and 43/45 or 96%, respectively). The extent of anatomical damage as expressed by the incidence of an avulsion of one or more spinal nerves was 18/26 (69%) in Erb C5-C6, 13/59 (22%) in Erb C5-C7 and 21/45 (47%) in total C5-T1 palsy.

CONCLUSION

The Erb's C5-C6 palsy, occasionally bilateral and/or complicated by phrenic nerve injury, was the most frequent form of OBPL after a breech birth. The more extensive form of Erb's palsy and the total palsy were observed more frequently after delivery in a cephalic presentation. The pure form of Erb's palsy and the total palsy were characterised by a higher incidence of nerve avulsions than the extensive form of Erb's palsy.

Effect of placental laterality on uterine artery resistance and development of preeclampsia and intrauterine growth retardation

We studied 153 pregnant women with normal pregnancies and 147 women with complicated pregnancies (diabetes, hypertensive disorders, and intrauterine growth retardation) to evaluate the association of placental location and the development of preeclampsia, intrauterine growth retardation, and uterine artery resistance. The placental location was determined by real-time ultrasonography, and the uterine artery resistance was determined by continuous-wave Doppler flow velocity waveform analysis. In the presence of preeclampsia or intrauterine growth retardation, up to 75% of the patients had unilaterally located placentas and 25% central placentas, whereas in the absence of these two conditions only 51% of the patients had unilateral and 49% central placentas (p less than 0.02). In patients with unilateral placentas, the incidence of preeclampsia and intrauterine growth retardation was 2.8-fold and 2.7-fold greater than in patients with central placentas (p less than 0.03 and p less than 0.01). Among all patients unilateral placental location was more likely to be associated with abnormal artery flow velocity waveforms than central placental location (p less than 0.001). We conclude that unilateral placental location may predispose to the development of preeclampsia and intrauterine growth retardation by its effect on uterine artery resistance.