Factors Associated with More Than 500 Grams Inaccuracy in Sonographic Fetal Weight Estimation.

BACKGROUND: The sonographic assessment of estimated fetal weight (EFW) is essential for identification of fetuses in weight extremes and aids in peripartum management. However, there are inconsistent reports regarding EFW accuracy. OBJECTIVES: To examine maternal and fetal determinants associated with unreliable EFW. METHODS: A retrospective case-control study was conducted at a single, tertiary medical center between 2011 and 2019. All term, singleton deliveries with a sonographic EFW within 2 weeks of delivery were included. Unreliable EFW was defined as > 500 grams discordance between it and the actual birth weight. We allocated the study cohort into two groups: unreliable EFW (cases) and accurate EFW (controls). RESULTS: Overall, 41,261 deliveries met inclusion criteria. Of these, 1721 (4.17%) had unreliable EFW. The factors positively associated with unreliable EFW included body mass index > 30 kg/m2, weight gain > 20 kg, higher amniotic fluid index, pregestational diabetes, gestational age > 410/7, and birth weight ≥ 4000 grams. On multiple regression analysis, pregestational diabetes (odds ratio [OR] 2.22, 95% confidence interval [95%CI] 1.56-3.17, P < 0.001) and a higher birth weight (OR 1.91, 95%CI 1.79-2.04, P < 0.001) were independently associated with unreliable EFW. On analysis of different weight categories, pregestational diabetes was associated with unreliable EFW only among birth weights ≥ 3500 grams (OR 3.28, 95%CI 1.98-5.44, P< 0.001) and ≥ 4000 grams (OR 4.27, 95%CI 2.31-7.90, P < 0.001). CONCLUSIONS: Pregestational diabetes and increased birth weight are independent risk factors for unreliable EFW and should be considered when planning delivery management.

Sonographic fetal head circumference and the risk of obstetric anal sphincter injury following vaginal delivery.

INTRODUCTION: High birth weight is strongly associated with OASIS; nevertheless, it has not been determined which biometric characteristics most affect OASIS occurrence. We aimed to evaluate the association of estimated fetal head circumference with OASIS occurrence among primiparous women delivering by unassisted vaginal delivery. METHODS: A retrospective study included all primiparous women who delivered at term by spontaneous vaginal delivery from 2011-2019. Women were allocated to two groups: (1) those who experienced OASIS and (2) those who did not experience OASIS. Risk factors for OASIS were analyzed. RESULTS: Overall, 7646 women were included in the study cohort. Of those, 119/7646 (1.6%; 95% CI, 1.3-1.9%) experienced OASIS. Sonographic head circumference and birth weight did not vary between groups. Prolonged second stage was more common in the OASIS group [23 (19%) vs. 986 (13.3%), 1.58 OR (95% CI 1.003-2.51, p = 0.04)]. Absence of epidural analgesia was more common in the OASIS group [30 (25%) vs. 1197 (15.9%), 1.8 OR (95% CI 1.1-2.7, p = 0.006)]. On multivariate logistic regression analysis, the lack of epidural analgesia and duration of second stage of labor were both independently positively associated with OASIS [adjusted OR 2.67 (95% CI 1.55-4.62), p < 0.001, adjusted OR 1.23 (95% CI 1.11-1.43), p < 0.001, respectively)]. CONCLUSION: Sonographic head circumference and birth weight are not associated with OASIS occurrence among primiparous women delivering by an unassisted vaginal delivery. Prolonged second stage and the use of epidural analgesia are modifiable risk factors among these women.

Does birthweight have a role in the effect of episiotomy on anal sphincter injury?

PURPOSE: Most professional guidelines advise against routine episiotomy during vaginal delivery, although mounting evidence supports its protective role regarding obstetric anal sphincter injury (OASI). We aimed to study the effect of lateral and mediolateral episiotomies on the rate of OASI in relation to birthweight among nulliparous women undergoing vaginal delivery. METHODS: A historical cohort study was conducted of all nulliparous women who delivered vaginally at term between 2011 and 2019 at a tertiary university hospital. Women were allocated into two groups: (1) with OASI and (2) without OASI. Episiotomy performance and birthweight groups were analyzed. RESULTS: Overall, 22,250 deliveries were analyzed for inclusion: 18,533 (83.3%) spontaneous vaginal deliveries (SVD), 3222 (14.5%) vacuum-assisted deliveries (VAD) and 495 (2.2%) forceps deliveries. Total episiotomy and OASI rate was 48.2% and 1.7%, respectively. Episiotomy rate was lower in the OASI group as compared to the no OASI group (158 (41.3%) vs. 10,568 (48.3%), OR 0.75, 0.61-0.92, p = 0.006). Median birthweight was higher for OASI group neonates (3355 vs. 3160, p < 0.001). In SVDs, episiotomy decreased the rate of OASI in neonatal birthweight groups of 3000-3499, 3500-3999 and > 4000 g (OR 0.56, 0.38-0.82, p = 0.003; 0.66, 0.45-0.99, p = 0.04 and 0.24, 0.07-0.78, p = 0.01, respectively). In VADs, episiotomy decreased the rate of OASI in the neonatal weight groups of 2500-2999 and 3000-3499 g (OR 0.36, 0.14-0.89, p = 0.02 and OR 0.38, 0.19-0.75, p = 0.004, respectively). CONCLUSIONS: Lateral and mediolateral episiotomies are independent modifiable predictors of OASI, protective against OASI in SVDs when neonates weigh > 3000 g and 2500-3499 g in VADs.

Prenatal Diagnosis of Vasa Previa: Outpatient versus Inpatient Management.

OBJECTIVE: The aim of this study was to compare the pregnancy outcome of two different management strategies: outpatient versus inpatient in women with prenatal diagnosis of vasa previa. MATERIALS AND METHODS: This is a retrospective cohort study conducted at a single tertiary center. Women with a prenatally diagnosed vasa previa between January 2007 and June 2017 were included. Obstetric and neonatal outcomes were compared between two management strategies: elective admission at 34 weeks of gestation or outpatient management unless there were signs of labor or premature contractions. RESULTS: A total of 109 women met the inclusion criteria: 75 (68.8%) women in the inpatient group and 34 (31.2%) in the outpatient group. Women in the inpatient group were more likely to receive antenatal steroids (57.3 vs. 26.4%, p = 0.002) and were less likely to have an urgent cesarean section (34.6 vs. 58.8%, respectively, p < 0.001) compared with outpatient group. There was no difference in the rate of neonatal complications (inpatient: 64.6% vs. outpatient: 52.7%, p = 0.27) or neonatal anemia requiring transfusion (2.7 vs. 5.8%, respectively, p = 0.5) between the groups. CONCLUSION: The rate of elective cesarean section and exposure to antenatal steroids was higher in patients with vasa previa who were admitted electively at 34 weeks of gestation compared with patients who were managed as outpatient.

The effect of fetal weight on the accuracy of sonographic weight estimation among women with diabetes.

OBJECTIVE: The assessment of sonographic estimated fetal weight (EFW) enables identification of fetuses in the extremes of weight, thus aiding in the planning and management of peripartum care. There are conflicting reports regarding the accuracy of EFW in diabetic mothers. We aimed to study the factors associated with the accuracy of EFW at term, specifically the role of gestational and pre-gestational diabetes in this setting. METHODS: A retrospective study including all women carrying singleton term gestations who delivered within a week following a sonographic fetal weight estimation between 2011 and 2019. Accurate EFW was defined as within 10% of the actual birthweight. We allocated the study cohort into two groups: (1) Accurate EFW (2) inaccurate EFW. Both groups were compared in order to identify factors associated with the inaccuracy of EFW. RESULTS: Overall, 41,263 deliveries were available for evaluation, including 412 (1.0%) deliveries among women with pre-gestational diabetes and 4,735 (11.5%) among women with gestational diabetes. Of them, 7,280 (17.6%) had inaccurate EFW. Inaccurate EFW was associated with nulliparity, OR 0.82 [95% CI] (0.78-0.87), oligohydramnios, OR 0.81 [95% CI] (0.71-0.93), pregestational diabetes, OR [95% CI] 0.61 (0.50-0.79), and extremity of fetal weight; <2,500 grams-OR [95% CI] 0.37 (0.33-0.41) and >4,000 grams OR [95% CI] 0.52 (0.48-0.57). On multiple regression analysis, the following factors were independently associated with inaccurate EFW: pregestational diabetes, OR [95% CI] 0.58 (0.46-0.73), p < .001, nulliparity, OR [95% CI] 0.86 (0.82-0.91), p < .001 and higher fetal weight (for each 500 grams), OR [95% CI [1.25 (1.21-1.30), p < .001. On analysis of different weight categories, pregestational diabetes was associated with inaccurate EFW only in those with birthweight >3,500 grams, OR [95% CI] 0.37 (0.24-0.56) (p < .001). CONCLUSION: Among pregestational diabetic women, the accuracy of sonographic EFW when assessed to be >3,500 grams is questionable. This should be taken into consideration when consulting women and planning delivery management. SYNOPSIS: Among pregestational diabetic women, the accuracy of estimated sonographic fetal weight higher than 3,500 grams is of limited accuracy.

Predictors of adverse neonatal outcome in pregnancies complicated by placenta previa.

INTRODUCTION: We aimed to underline the determinants of adverse neonatal outcome in gestations complicated by placenta previa (PP). METHODS: A retrospective study including all women diagnosed with placenta previa carrying a singleton gestation who delivered between 2011 and June 2019. Gestations with adverse neonatal outcomes were compared to those without. In a secondary analysis, we further studied the rate of Placenta accreta spectrum (PAS) in relation to number of previous cesarean deliveries. RESULTS: Overall, 548/84,558 (0.6%) singleton deliveries were complicated by PP (0.6%). PAS was noted in 105 (19.2%) cases. After exclusion of PAS cases, adverse neonatal outcome occurred in 149/443 (33.6%), median gestational age of delivery was 37 0/7 with a median birthweight of 2780 g. In a univariate analysis, adverse neonatal outcome was associated with emergent delivery and general anesthesia [56.8% vs. 20.8%, OR 5.00 (95% CI) 3.24-7.72, p < 0.001 and 54.4% vs. 24.8%, OR 3.60 (95% CI) 2.37-5.47, p < 0.001, respectively]. Gestational age at delivery was lower in the adverse outcome group (mean 35 1/7 vs. 37 3/7, p < 0.001). In a multivariate regression analysis, general anesthesia and gestational age at delivery were independently associated with adverse neonatal outcome [adjusted odds ratio (aOR) 2.26 (95% CI) 1.18-4.31, p = 0.01, aOR 1.10 (95% CI) 1.05-1.16, p < 0.001. Analysis of the rate of PAS among women with previous cesarean delivery and PP revealed that no cases of PAS were noted when no prior cesarean delivery was present. The rate of PAS for previous 1, 2, 3, 4 and 5 cesarean deliveries was 26.7%, 43.5%, 65.5%, 55.6% and 66.7% respectively. DISCUSSION: Efforts should be made to avoid general anesthesia in deliveries of PP.

Trial of labor after cesarean (TOLAC) in women with premature rupture of membranes.

Introduction: The aim of this study was to assess the success rate of a trial of labor after a previous cesarean section (TOLAC) in the settings of premature rupture of membranes (PROM) and to compare conservative management with spontaneous labor and induction of labor.Methods: This was a retrospective cohort study conducted in a single tertiary care center between January 2011 and March 2017. Women with singleton pregnancy and a previous cesarean section (CS) who presented with PROM and underwent TOLAC were included. Outcomes and rate of successful vaginal delivery after induction of labor were compared to conservative treatment and spontaneous labor.Results: Among 830 women who met the inclusion criteria, 723 (87.1%) had a spontaneous onset of labor following PROM and 107 (12.9%) had an induction of labor. The rate of successful TOLAC was similar between the groups (75.7 vs. 81.6%, respectively, p = .22). However, induction of labor was associated with an increased risk for uterine rupture (1.87 vs. 0.96%, p < .001), operative complications (6.7 vs. 2.3%, p < .001), and composite maternal postpartum complications (21.4 vs. 10.7%, respectively, p = .014) compared to conservative management with spontaneous initiation of labor. There was no difference in neonatal outcome between the groups.Conclusion: Induction of labor following PROM in women with a previous CS is associated with high successful vaginal delivery rate. However, the risk for uterine rupture and operative and maternal complications is significantly increased compared to spontaneous initiation of labor.