Sonographic markers of fetal adiposity and risk of Cesarean delivery.

OBJECTIVE: Increased fetal size is associated with shoulder dystocia during labor and subsequent need for assisted delivery. We sought to investigate if increased fetal adiposity diagnosed sonographically in late pregnancy is associated with increased risk of operative delivery. METHODS: This secondary analysis of the Genesis Study recruited 2392 nulliparous women with singleton pregnancy in cephalic presentation, in a prospective, multicenter study, to examine prenatal and intrapartum predictors of Cesarean delivery. Participants underwent ultrasound and clinical evaluation between 39 + 0 and 40 + 6 weeks' gestation. Data on fetal biometry were not revealed to patients or to their managing clinicians. A fetal adiposity composite of fetal thigh adiposity and fetal abdominal wall thickness was compiled for each infant in order to determine whether fetal adiposity > 90th centile was associated with an increased risk of Cesarean or operative vaginal delivery. RESULTS: After exclusions, data were available for 2330 patients. Patients with a fetal adiposity composite > 90th centile had a higher maternal body mass index (BMI) (25 ± 5 kg/m2 vs 24 ± 4 kg/m2 ; P = 0.005), birth weight (3872 ± 417 g vs 3585 ± 401 g; P < 0.0001) and rate of induction of labor (47% (108/232) vs 40% (834/2098); P = 0.048) than did those with an adiposity composite ≤ 90th centile. Fetuses with adiposity composite > 90th centile were more likely to require Cesarean delivery than were those with adiposity composite ≤ 90th centile (P < 0.0001). After adjusting for birth weight, maternal BMI and need for induction of labor, fetal adiposity > 90th centile remained a risk factor for Cesarean delivery (P < 0.0001). A fetal adiposity composite > 90th centile was more predictive of the need for unplanned Cesarean delivery than was an estimated fetal weight > 90th centile (odds ratio, 2.20 (95% CI, 1.65-2.94; P < 0.001) vs 1.74 (95% CI, 1.29-2.35; P < 0.001). Having an adiposity composite > 90th centile was not associated with an increased likelihood of operative vaginal delivery when compared with having an adiposity composite ≤ 90th centile (P = 0.37). CONCLUSIONS: Fetuses with increased adipose deposition are more likely to require Cesarean delivery than are those without increased adiposity. Consideration should, therefore, be given to adding fetal thigh adiposity and abdominal wall thickness to fetal sonographic assessment in late pregnancy. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Does anal sphincter injury preclude subsequent vaginal delivery?

OBJECTIVE: To assess continence and anal sphincter integrity during a subsequent pregnancy and delivery in women known to have a previous anal sphincter injury. DESIGN: Prospective observational study. SETTING: The National Maternity Hospital, Dublin, Ireland. POPULATION: Antenatal patients with a documented obstetric anal sphincter injury at a previous delivery. METHODS: Women underwent symptom scoring, endoanal ultrasound and manometry. MAIN OUTCOME MEASURES: Recommended and actual mode of delivery, continence scores and endoanal ultrasound findings after index delivery. RESULTS: 557 women were studied. 293 (53%) had no symptoms of faecal incontinence, 189 (34%) had mild symptoms and 75 (13%) moderate or severe symptoms. 408 (73%) had an endoanal ultrasound. 383(94%) had a normal or small (<1 quadrant) defect in the internal anal sphincter and 390 (96%) had a scar or small (<1e quadrant) defect in the external anal sphincter. 393 (70%) delivered vaginally. 164 (30%) were delivered by caesarean section. 197/557 (35%) returned for follow-up. There was no significant change in continence following either vaginal or caesarean delivery. 20 (5.1%) women had a recognised second anal sphincter tear during vaginal delivery. CONCLUSIONS: The majority of women who sustain a third degree tear have minimal or no symptoms of faecal incontinence when assessed antenatally in a subsequent pregnancy. 70% go on to have a vaginal delivery, with little impact on faecal continence. These findings provide reassurance for patients and clinicians about the safety of vaginal delivery following anal sphincter injury in appropriately selected patients.

Are women having a vaginal birth after a previous caesarean delivery at increased risk of anal sphincter injury?

OBJECTIVE: To examine the incidence of obstetric anal sphincter injury in women who had a successful vaginal birth after a previous caesarean delivery (VBAC). DESIGN: Retrospective analysis of prospectively gathered data. SETTING: A tertiary referral university institution. POPULATION: All secundiparous women with a previous caesarean delivery who had a VBAC from 2001 to 2011. METHODS: Details of maternal demographics, intrapartum characteristics and outcomes were examined in cases of VBAC with accompanying anal sphincter injury. MAIN OUTCOME MEASURES: Rates of obstetric anal sphincter injury and associated risk factors. RESULTS: During the study period there were 3071 trials of labour in secundiparous women with a previous caesarean delivery; 65% (1981/3071) of these had a successful VBAC. Women having a VBAC were at greater risk of anal sphincter injury than nulliparous women having a vaginal delivery over the same period (5% [98/1981] versus 3.5% [1216/34,496], P = 0.001, odds ratio 1.4, 95% CI 1.15-1.75). The rate of instrumental delivery in woman having a VBAC was 39% (771/1981). On multiple logistic regression analysis an increased rate of instrumental delivery was a strong predictor of sphincter injury (P = 0.03, odds ratio 1.15, 95% CI 1.01-1.3). When the first labours of women with sphincter injury in the VBAC group were examined, 70% (60/86) had been in labour before undergoing their caesarean delivery. CONCLUSION: The incidence of anal sphincter injury in women undergoing VBAC is 5% and birthweight is the strongest predictor of this. The rate of instrumental delivery in this group was also increased.