The IRELAnD study-investigating the role of early low-dose aspirin in diabetes mellitus: a double-blinded, placebo-controlled, randomized trial.

BACKGROUND: Although aspirin therapy is being increasingly advocated with the intention of risk modification for a wide range of pregnancy complications, women with prepregnancy diabetes mellitus are commonly excluded from clinical trials. OBJECTIVE: The primary aim of this study was to examine the effect of aspirin therapy on a composite measure of adverse perinatal outcome in pregnancies complicated by pregestational diabetes mellitus. STUDY DESIGN: A double-blinded, placebo-controlled randomized trial was conducted at 6 university-affiliated perinatology centers. Women with type 1 diabetes mellitus or type 2 diabetes mellitus of at least 6 months' duration were randomly allocated to 150-mg daily aspirin or placebo from 11 to 14 weeks' gestation until 36 weeks. Established vascular complications of diabetes mellitus, including chronic hypertension or nephropathy, led to exclusion from the trial. The primary outcome was a composite measure of placental dysfunction (preeclampsia, fetal growth restriction, preterm birth <34 weeks' gestation, or perinatal mortality). The planned sample size was 566 participants to achieve a 35% reduction in the primary outcome, assuming 80% statistical power. Secondary end points included maternal and neonatal outcomes and determination of insulin requirements across gestation. Data were centrally managed using ClinInfo and analyzed using SAS 9.4. The 2 treatment groups were compared using t tests or chi-square tests, as required, and longitudinal data were compared using a repeated-measures analysis. RESULTS: From February 2020 to September 2022, 191 patients were deemed eligible, 134 of whom were enrolled (67 randomized to aspirin and 67 to placebo) with a retrospective power of 64%. A total of 101 (80%) women had type 1 diabetes mellitus and 25 (20%) had type 2 diabetes mellitus. Reaching the target sample size was limited by the impact of the COVID-19 pandemic. Baseline characteristics were similar between the aspirin and placebo groups. Treatment compliance was very high and similar between groups (97% for aspirin, 94% for placebo). The risk of the composite measure of placental dysfunction did not differ between groups (25% aspirin vs 21% placebo; P=.796). Women in the aspirin group had significantly lower insulin requirements throughout pregnancy compared with the placebo group. Insulin requirements in the aspirin group increased on average from 0.7 units/kg at baseline to 1.1 units/kg by 36 weeks' gestation (an average 83% within-patient increase), and increased from 0.7 units/kg to 1.3 units/kg (a 181% within-patient increase) in the placebo group, over the same gestational period (P=.002). Serial hemoglobin A1c levels were lower in the aspirin group than in the placebo group, although this trend did not reach statistical significance. CONCLUSION: In this multicenter, double-blinded, placebo-controlled randomized trial, aspirin did not reduce the risk of adverse perinatal outcome in pregnancies complicated by prepregnancy diabetes mellitus. Compared with the placebo group, aspirin-treated patients required significantly less insulin throughout pregnancy, indicating a beneficial effect of aspirin on glycemic control. Aspirin may exert a plausible placenta-mediated effect on pregestational diabetes mellitus that is not limited to its antithrombotic properties.

Is the older perineum a safer perineum? Risk factors for obstetric anal sphincter injury.

INTRODUCTION: Obstetric anal sphincter injury (OASI) is the most common cause of anal incontinence. Identifying risk factors may facilitate change in labour and delivery practice, potentially reducing the risk. The objective of this study is to identify maternal, foetal and intrapartum risk factors for OASI in a regional hospital. METHOD: We conducted a retrospective analysis of vaginal deliveries over a 10-year period (2008-2017). Anal sphincter injury was diagnosed by an experienced clinician and classified according to RCOG recommendations. A multiple logistic regression model was created using the presence of OASI as the dependent variable. Coefficients were adjusted for relevant maternal, foetal and intrapartum risk factors. RESULTS: During the study period, there were 23,887 vaginal deliveries. Of these births, 18,550 were spontaneous (77.66%), 3746 vacuum-assisted (15.68%), 1196 forceps (5.01%) and 395 sequential instrumental deliveries (1.65%). The overall rate of OASI was 1.76%, with an upward trend seen in nulliparous mothers. Significant factors that increased the risk of OASI were nulliparity, Asian ethnicity, delivery by forceps or sequential instruments, and shoulder dystocia. Vacuum delivery did not significantly increase risk. CONCLUSION: Maternal age ≥ 35 years confers a protective effect after adjusting for parity, birth weight and mode of delivery. Given the context of an ageing reproductive population, additional research is required to investigate the impact of maternal age on anal sphincter injury.

Are women attending a midwifery-led birthing center at increased risk of anal sphincter injury?

INTRODUCTION AND HYPOTHESIS: In recent years there has been renewed interest in midwifery-led care for women, with studies reporting similar neonatal outcomes despite lower rates of intervention in midwifery-led birthing centers. Research into obstetric anal sphincter injuries (OASI) in these birthing centers is scarce. The objective of this study was to compare the rate of OASI after spontaneous vaginal delivery in nulliparous women in consultant or midwifery-led units over a ten-year period. METHODS: All spontaneous vaginal deliveries in nulliparous women from 2008 to 2017 were analyzed in a single-center retrospective study. Women who had neuraxial analgesia were excluded. The primary endpoint was OASI. Labor characteristics in both groups were compared, and a multiple regression model was created. RESULTS: During the study period, there were 3260 spontaneous vaginal deliveries in nulliparous women; 75.7% (2467/3260) delivered in the consultant-led unit and 24.3% (793/3260) in the midwifery-led unit (MLU). Women delivering in the MLU had a greater risk of anal sphincter injury than those delivering in the CLU (4.9% [39/793] vs 2.5% [62/2467], OR 2.01, 95% CI 1.32 - 3.01). Significant risk factors that increased the risk of OASI on regression analysis were birthweight and delivery in the midwifery-led unit. CONCLUSIONS: Women delivering in the midwifery-led unit appear to be at double the risk of OASI when compared to those delivering in the consultant-led unit. These results are in contrast to previous studies in midwifery-led centers. This difference may be site-specific and further research is required before these results form part of patient counseling.

Anal sphincter injury associated with shoulder dystocia.

Objective: Shoulder dystocia is an obstetric emergency, occurring in 0.2-3% of vaginal deliveries. Research has mainly focused on the neonatal morbidity arising from shoulder dystocia, such as brachial plexus injury and hypoxic-ischemic encephalopathy. Maternal morbidity is thought to be increased with shoulder dystocia though is much less commonly reported. Obstetric anal sphincter injury remains the leading cause of fecal incontinence in women and shares several antenatal and intrapartum risk factors with shoulder dystocia. The aim of this study was to identify risk factors for sphincter injury associated with shoulder dystocia.Methods: This retrospective analysis included all cases of shoulder dystocia from 2008 to 2017 in a single unit in North-East Ireland. Maternal characteristics and delivery outcomes were analyzed. Two groups were compared, those with and without anal sphincter injury in our shoulder dystocia cohort and those with and without shoulder dystocia, regardless of sphincter injury. Univariate and multivariate logistic regression models were used to examine risk factors for sphincter injury.Results: There were 24,159 singleton cephalic vaginal deliveries over the study period, with 495 cases of shoulder dystocia, giving an incidence of 2.1% (495/24 159). The rate of anal sphincter injury in those with shoulder dystocia was 4.4% (22/495), with 7.6% (12/158) in nulliparas, and 3.0% (10/337) among multiparas. Women with sphincter damage were more likely to be nulliparous than those with an intact sphincter (54.5% [12/22] vs. 30.9% [146/473]; p = .036) and have an operative vaginal delivery (72.7% [16/22] vs. 39.1% [185/473]; p = .004). Episiotomy was more common in those with a sphincter injury (68.2% [15/22] vs. 37.0% [175/473]; p = .007). On univariate regression analysis, nulliparity (OR 2.69) and operative vaginal delivery (OR 4.15) were associated with sphincter injury. No risk factors were identified on multivariate regression analysis.Discussion: In our population, the risk of anal sphincter injury with shoulder dystocia is 4.4%. Risk factors include nulliparity and operative vaginal delivery. After controlling for other factors, these associations became nonsignificant. Further research into sphincter injury at shoulder dystocia is warranted.

Single prior caesarean section and risk of anal sphincter injury.

INTRODUCTION AND HYPOTHESIS: Injury to the anal sphincter at vaginal delivery remains the leading cause of faecal incontinence in women. Previous studies reported an increased incidence of obstetric anal sphincter injury (OASI) in women attempting vaginal birth after caesarean section (VBAC). The aim of the paper was to establish whether women in their second pregnancy, with one previous uterine scar, are at a higher risk of OASI compared with nulliparous women. METHODS: All primiparous and secundiparous women with a previous caesarean section who delivered from 2008 to 2017 were analysed in a single-centre retrospective study. The primary endpoint was OASI. Labour characteristics in both groups were compared, and a multiple regression model was created. RESULTS: There were 8573 vaginal deliveries of nulliparous women and 3453 deliveries of women in their second pregnancy with a previous caesarean section, of whom 550 had a successful VBAC. There was no significant difference in the rate of OASI between primiparous women and those who had a successful VBAC: 3.5% (297/8573) versus 3.1% (17/550), P = 0.730). Foetal macrosomia (>4 kg) and forceps delivery were risk factors for sphincter injury, while episiotomy and epidural anaesthesia were protective. CONCLUSIONS: VBAC does not confer an increased risk of OASI after a first delivery by caesarean section when compared with nulliparous women. The rate of successful VBAC may be contributory and suggests that the risk conferred by VBAC may be unit-specific. Unit and national-level audit is necessary to investigate this risk further.