Attempted and Successful Vacuum-Assisted Vaginal Delivery by Prepregnancy Body Mass Index

Abstract

Objective To examine rates of attempted and successful vacuum-assisted vaginal delivery by pre-pregnancy body mass index (BMI). Methods We conducted a retrospective cohort study of 2,084 women with singleton gestations needing operative delivery assistance and vacuum-eligible (fully dilated, ≥ +2 station, ≥34 weeks) using 2006–2014 in-patient records. Pre-pregnancy BMI was categorized as underweight (<18.5kg/m2), normal weight (18.5kg/m2≤BMI<25kg/m2), overweight (25kg/m2≤ BMI<30kg/m2), or obese (≥30kg/m2). Logistic regression models estimated odds ratios (ORs) and 95% confidence intervals (CIs) of attempted and successful vacuum-assisted vaginal delivery by pre-pregnancy BMI adjusted for age, race, marital status, parity, diabetes, labor induction–augmentation, episiotomy, gestational age, and infant birth weight. Results Thirty-nine percent of women requiring delivery assistance and eligible for a vacuum were overweight or obese, 79% had vacuum attempts, and 95.3% of attempted vacuum-assisted vaginal deliveries were successful. Compared to women who were normal weight pre-pregnancy (82.8%), women who were overweight or obese were less likely to have vacuum attempted (75.8%, OR=0.71, 95% CI 0.53–0.96 and 71.2%, OR=0.53, 95% CI 0.39–0.74, respectively). Among women with attempted vacuum-assisted vaginal delivery, successful delivery did not differ by pre-pregnancy BMI (92.6%, OR=0.54, 95% CI 0.21–1.37 for underweight; 94.5%, OR=1.07, 95% CI 0.57–2.00 for overweight; 96.3%, OR=1.09, 95% CI 0.51–2.33 for obese, versus 95.6% among normal weight women). Conclusions Among women in need of operative delivery assistance, pre-pregnancy obesity was associated with lower likelihood of attempted vacuum-assisted vaginal delivery, but if attempted, success rates were similar to rates among normal weight women. With significant morbidity of second stage cesarean delivery in obese women, research should examine whether vacuum-assisted vaginal delivery may be appropriate for additional obese patients.

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

“…A recent prospective cohort study of Norwegian women found 50% higher rates of vacuum-assisted vaginal delivery among women with class III obesity compared to normal weight women [25]. However, a recent study in US showed lower odds of attempted assisted vaginal delivery in obese women, similar to our findings [26]. It should be noted that rates of cesarean delivery in Norway were much lower than those in the US and China during the study period [27].…”

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).…”

Glucose Levels of the Oral Glucose Tolerance Test (oGTT) Can Predict Adverse Pregnancy Outcomes in Women with Gestational Diabetes (GDM)

“…This goes along with a recent analysis, that was able to demonstrate an association of vacuum extraction and nulliparity [25]. Ramos et al examined women requiring operative delivery assistance and found a decreased likelihood of vaginal operative delivery in women with pre-pregnancy obesity [26].…”