Effects of maternal obesity on the success of assisted vaginal delivery in Chinese women

Abstract

BackgroundWe examined the influence of pre-pregnancy body weight on the rates of attempted and successfully assisted-vaginal delivery.MethodsWe used 2008–2016 inpatient records including 3408 women who had singleton gestations and needed operative delivery assistance to conduct a retrospective cohort study. Patients were categorized based on pre-pregnancy BMI (normal weight = 18.5 to less than 25 or obese = 30 or greater). We used logistic regression to estimate odds ratios and 95% confidence intervals of attempted and successful forceps or vacuum-assisted vaginal delivery by body weight adjusted for marital status, age, gestational age, induction of labor, episiotomy, diabetes, and birth weight.ResultsThe proportion of women with attempted either vacuum or forceps was lower among women who were obese pre-pregnancy compared to women who were normal weight. Women with excessive gestational weight gain, large for gestational age neonates, and diabetes were less likely to have a vacuum-assisted or forceps-assisted vaginal delivery attempted. Conversely, women who received labor augmentation or induction, used epidural anesthesia, gained inadequate weight, and delivered a small for gestational age infant were more likely to have a vacuum-assisted or forceps-assisted vaginal delivery attempted. Compared to normal weight women, obese women who received forceps-assisted vaginal delivery were more likely to have a successful vaginal delivery.ConclusionWomen who had normal weight had higher likelihood to attempt assisted vaginal delivery compared to women who had pre-pregnancy obesity. However, when assisted vaginal delivery was attempted, success rates were higher when forceps-assisted delivery was used compared to vacuum-assisted delivery.

Trends and Determinants of Operative Vaginal Delivery at Two Academic Hospitals in Johannesburg, South Africa 2005–2019

“…From our cross-sectional study, the prevalence of OVDs was higher among women that were underweight, while obese patients had the highest prevalence of vaginal deliveries. We also found that the odds of OVDs reduces with increasing BMI as was also reported by Yu and Wue in China and other authors [ 43 , 44 ]. This finding may also suggest that patients with higher BMI may have very roomy pelvis and may not require assisted delivery.…”

“…This observed reduced odds of OVDs with increasing BMI will only be valid among women with adequate pelvis, as one of the requirements for OVD is a clinically adjudged adequate pelvis with no feature of cephalopelvic disproportion [ 45 ]. However, this pattern may not be absolute as increased birthweight and increased prevalence of medical conditions in pregnancy such as hypertension, cardiac disease and diabetes may be commoner among obese women thereby leading to increased caesarean section rates among obese women [ 43 , 46 , 47 , 48 ]. Since one of the indications for OVDs is prolonged second stage of labor, it may not be surprising that there were 11% higher odds of OVDs for every extra hour of labor.…”

Overweight, obesity and excessive weight gain in pregnancy as risk factors for adverse pregnancy outcomes: A narrative review

“…and, to some extent, this is driven by medical staff seeking to minimise risk to the baby and mother. Women who are obese and whose labour is not progressing are less likely than women of ideal weight to be allowed to attempt a vaginal delivery with assistance from forceps or a vacuum cap (ventouse), but, when they are allowed to do so, appear to have better outcomes than ideal weight women 88,89 . With caesarean section recovery is slower and surgical complications are more likely with obesity 90,91 …”

“…Women who are obese and whose labour is not progressing are less likely than women of ideal weight to be allowed to attempt a vaginal delivery with assistance from forceps or a vacuum cap (ventouse), but, when they are allowed to do so, appear to have better outcomes than ideal weight women. 88,89 With caesarean section recovery is slower and surgical complications are more likely with obesity. 90,91 Post-partum haemorrhage occurs in up to 5% of women and is characterised by either heavy blood loss during delivery (in excess of 500 ml following vaginal delivery or 1 litre following a caesarean) or in the following days (as a result of placental retention, uterine atony or rupture).…”

A model to predict delivery time by induction of labour at term with a dinoprostone vaginal insert：A retrospective study

“…Many studies have identi ed women with high BMIs as an independent risk factor for vaginal delivery [35,36]. A cohort study, which included more than 5,000 parturients, found that compared to women with a BMI less than 30, obese women with a higher BMI had a longer duration and slower progression of the rst stage of labour, but no differences were found in the timing of cervical dilation from 6 cm to complete dilation [37].…”