Follow up of women after obstetric anal sphincter injuries (OASI)-What is the role of anorectal testing?

AIMS: To evaluate the benefit of performing anorectal studies on all women following primary obstetric anal sphincter injury (OASI) repair over performing them on symptomatic women only. METHODS: Women who attended perineal clinic between 2007 and 2020 underwent symptom assessment and anorectal studies at 6 weeks and 6 months postpartum. Anorectal studies including endo anal ultrasound (EAUS) and anal manometry (AM) were performed. The anorectal studies of symptomatic women who were the case group, were compared with asymptomatic women who were the control group. RESULTS: A total of 1348 women were seen in the perineal clinic over 13 years. A total of 454 (33.7%) women were symptomatic. A total of 894 (66.3%) women were asymptomatic. A total of 313 (35%) asymptomatic women had two abnormal anorectal studies, 274 (31%) had abnormal AM alone, and 86 (9.6%) had abnormal EAUS alone. A total of 221 (24.7%) asymptomatic women had normal anorectal studies. CONCLUSION: Almost 70% of women were asymptomatic 6 months following primary OASI repair. Most had at least one abnormal anorectal study result. Selectively performing anorectal tests on symptomatic women would not identify asymptomatic women at risk of future faecal incontinence following further vaginal birth. Without anorectal study results, women would not receive accurate counseling about the risks of vaginal birth. Anorectal studies should be offered to all women following OASI where resources allow.

The role of anal manometry in the follow-up of women with obstetric anal sphincter injuries (OASI).

INTRODUCTION AND HYPOTHESIS: Mode of birth (MOB) following OASI is determined by choice, symptoms and anorectal study results in asymptomatic women. Endoanal ultrasound (EAUS) is the gold-standard imaging modality. EAUS use in MOB counselling is supported by strong evidence. Less is understood about how anal manometry (AM) influences MOB counselling. METHODS: A retrospective observational study was conducted from 2007 to 2020. Women underwent symptom assessment using validated ePAQ and St Mark's incontinence score (SMIS). Anorectal studies using EAUS and AM were performed. The case group was the normal ultrasound group and the control group was the abnormal ultrasound group. Both groups were compared with normal and abnormal AM result groups. RESULTS: A total of 1348 women were included over 13 years. Among these, 454 women were symptomatic, 894 were asymptomatic; 274 (31%) asymptomatic women had isolated abnormal AM results, 313 (35%) had two abnormal anorectal results and 221 (24.7%) had normal anorectal results. Eighty-six asymptomatic women (10.4%) had isolated abnormal EAUS results, 138 (30.4%) symptomatic women had isolated abnormal AM, 221 (48.7%) had two abnormal anorectal results and 57 (12.6%) had normal anorectal results. Thirty-eight symptomatic women (8.4%) had an isolated abnormal EAUS result. CONCLUSIONS: AM identifies more women with sphincter function impairment than EAUS alone. Without AM, almost one third of asymptomatic women would not have been identified and could have been inadequately counselled. Performing AM and EAUS together captured most women with compromised anal sphincter function. We conclude that AM should be performed in all women with OASI alongside EAUS to enable accurate MOB counselling.

Evaluating the value of intrapartum fetal scalp blood sampling to predict adverse neonatal outcomes: A UK multicentre observational study.

OBJECTIVE: To evaluate the value of fetal scalp blood sampling (FBS) as an adjunct test to cardiotocography, to predict adverse neonatal outcomes. STUDY DESIGN: A multicentre service evaluation observational study in forty-four maternity units in the UK. We collected data retrospectively on pregnant women with singleton pregnancy who received FBS in labour using a standardised data collection tool. The primary outcome was prediction of neonatal acidaemia diagnosed as umbilical cord arterial pH < 7.05, the secondary outcomes were the prediction of Apgar scores<7 at 1st and 5th minutes and admission to the neonatal intensive care unit (NICU). We evaluated the correlation between the last FBS blood gas before birth and the umbilical cord blood and adjusted for time intervals. We constructed 2 × 2 tables to calculate the sensitivity, specificity, positive (PPV) and negative predictive value (NPV) and generated receiver operating curves to report on the Area Under the Curve (AUC). RESULTS: In total, 1422 samples were included in the analysis; pH values showed no correlation (r = 0.001, p = 0.9) in samples obtained within an hour (n = 314), or within half an hour from birth (n = 115) (r=-0.003, p = 0.9). A suboptimal FBS pH value (<7.25) had a poor sensitivity (22%) and PPV (4.9%) to predict neonatal acidaemia with high specificity (87.3%) and NPV (97.4%). Similar performance was noted to predict Apgar scores <7 at 1st (sensitivity 14.5%, specificity 87.5%, PPV 23.4%, NPV 79.6%) and 5th minute (sensitivity 20.3%, specificity 87.4%, PPV 7.6%, NPV 95.6%), and admission to NICU (sensitivity 20.3%, specificity 87.5%, PPV 13.3%, NPV 92.1%). The AUC for FBS pH to predict neonatal acidaemia was 0.59 (95%CI 0.59-0.68, p = 0.3) with similar performance to predict Apgar scores<7 at 1st minute (AUC 0.55, 95%CI 0.51-0.59, p = 0.004), 5th minute (AUC 0.55, 95%CI 0.48-0.62, p = 0.13), and admission to NICU (AUC 0.58, 95%CI 0.52-0.64, p = 0.002). Forty-one neonates had acidaemia (2.8%, 41/1422) at birth. There was no significant correlation in pH values between the FBS and the umbilical cord blood in this subgroup adjusted for sampling time intervals (r = 0.03, p = 0.83). CONCLUSIONS: As an adjunct tool to cardiotocography, FBS offered limited value to predict neonatal acidaemia, low Apgar Scores and admission to NICU.