Vaginal breech delivery of pregnancy before and after the estimated due date-A prospective cohort study.

INTRODUCTION: 3-4% of pregnant women present with a fetal breech position at term. National societies regard vaginal breech delivery as a safe option, but only for a specific and thoroughly counseled group of patients. To avoid adverse outcome, many practitioners recommend elective cesarean section once their patients go past the estimated due date. Since encompassing evidence is missing, the evaluation on this common clinical practice is needed. OBJECTIVE: This study compares the short-term maternal and fetal outcome in intended vaginally breech deliveries before the estimated due date (until 40 0/7 weeks of gestation) to the outcome of deliveries carried out past the estimated due date (later than 40 0/7 weeks of gestation). METHODS: This prospective cohort study includes 827 women who presented for an intended vaginal breech delivery of a singleton at our perinatal center between January 2010 and December 2016. RESULTS: 447 patients (54%) delivered before or at their estimated due date, 380 (46%) of pregnancies continued after the estimated due date. Comparing both groups, no significant difference in maternal and neonatal short-term mortality and morbidity was found. The rate of caesarian sections was increased in the group of patients, who delivered later than 40 1/7 weeks of gestation. Here, the likelihood for delivery maneuvers was also increased. CONCLUSION: This study provides evidence, that an elective cesarean section for breech presentations at term is not obligatory when the estimated due date has passed in singleton pregnancy.

MRI-based pelvimetric measurements as predictors for a successful vaginal breech delivery in the Frankfurt Breech at term cohort (FRABAT).

OBJECTIVES: The purpose of this study was to investigate the role of the maternal pelvis, assessed by MRI pelvimetry in nulliparous women expecting a term fetus in breech presentation, to predict a successful and safe vaginal birth. STUDY DESIGN: In this monocentric and anonymized cohort study, we enrolled 367 nulliparous women with breech presentation at 39+0 to 41+0 weeks of gestation during a period of 8 years at the University Women's Hospital in Frankfurt/Main. Pelvic measurements were obtained by standard MRI imaging. We correlated the obstetric conjugate, the pubic angle and the distance between the ischial tuberosities (intertuberous distance) with the maternal and fetal outcomes of vaginally intended breech births. The data was evaluated using logistic regression analysis. RESULTS: 241 of 367 participants (65.7%) experienced a successful vaginal delivery whereas 126 patients (34.3%) were subjected to secondary cesarean section. An increasing obstetric conjugate was significantly associated with an increasing rate of successful vaginal deliveries. No significant correlation of the intertuberous distance and the pubic angle with the mode of delivery could be shown. Although statistically not significant, we were able to define cut-off values of 10.9 cm in the intertuberous distance and 70° in the pubic angle; below these values, no successful vaginal delivery was recorded. No significant differences in the short-term outcomes were seen between the neonates of the vaginal delivery and the cesarean section groups. Inter- and intraobserver variability showed excellent reproducibility for all MRI parameters. CONCLUSION: The obstetric conjugate correlates with the rate of vaginal deliveries in nulliparous women at term and can be used as a useful criterion for pre-selection and counseling of women with breech presentation and the desire for a vaginal delivery.

Maternal and neonatal outcome after vaginal breech delivery at term of children weighing more or less than 3.8 kg: A FRABAT prospective cohort study.

INTRODUCTION: The clinical management of breech presentations at term is still a controversially discussed issue among clinicians. Clear predictive criteria for planned vaginal breech deliveries are desperately needed to prevent adverse fetal and maternal outcomes and to reduce elective cesarean section rates. The green-top guideline considers an estimated birth weight of 3.8 kg or more an indication to plan a cesarean section despite the lack of respective evidence. OBJECTIVE: To compare maternal and neonatal outcome of vaginal intended breech deliveries of births with children with a birth weight of 2.5 kg- 3.79 kg and children with a birth weight of 3.8 kg and more. DESIGN: Prospective cohort study. SAMPLE: All vaginal intended deliveries out of a breech position of newborns weighing between 2.5 kg and 4.5 kg at the Obstetrics department at Goethe University Hospital Frankfurt from January 2004 until December 2016. METHODS: Neonatal and maternal outcome of a light weight group (LWG) (< 3.8 kg) was compared to and a high weight group (HWG) (≥ 3.8 kg) using Pearson's Chi Square test and Fishers exact test. A logistic regression analysis was performed to detect an association between cesarean section rates, fetal outcome and the birth weight. RESULTS: No difference in neonatal morbidity was detected between the HWG (1.8%, n = 166) and the LWG (2.6%, n = 888). Cesarean section rate was significantly higher in the HWG with 45.2% in comparison to 28.8% in the LWG with an odds ratio of 1.57 (95% CI 1.29-1.91, p<0.0001). In vaginal deliveries, a high birth weight was not associated with an increased risk of maternal birth injuries (LWG in vaginal deliveries: 74.3%, HWG in vaginal deliveries: 73.6%; p = 0.887; OR = 1.9 (95% CI 0.9-1.1)). CONCLUSION: A fetal weight above 3.79 kg does not predict increased maternal or infant morbidity after delivery from breech presentation at term. Neither the literature nor our analyses document evidence for threshold of estimated birth weight that is associated with maternal and/or infant morbidity. However, patients should be informed about an increased likelihood of cesarean sections during labor when attempting vaginal birth from breech position at term in order to reach an informed shared decision concerning the birth strategy. Further investigations in multi center settings are needed to advance international guidelines on vaginal breech deliveries in the context of estimated birth weight and its impact on perinatal outcome.