Expert Commentary
Does mediolateral episiotomy reduce the risk of anal sphincter injury in operative vaginal delivery?
Yes.
The past year has seen the publication of four studies with relevance for clinicians:
- a retrospective cohort study that examined the maternal risks of operative vaginal delivery using forceps, vacuum extraction (FIGURE 1), or a combination of forceps and vacuum
- a prospective cohort study that investigated the efficacy and safety of three different techniques for midcavity rotational delivery in the setting of transverse arrest, namely manual rotation, vacuum rotation, and rotational forceps
- another retrospective cohort study that compared maternal morbidity among operative vaginal deliveries performed by midwives and physician providers in the United Kingdom
- a description of a new technique for instrumental vaginal delivery that is low-cost, simple, and easy to perform.
FIGURE 1. In trained hands, operative vaginal delivery can be an extremely effective intervention to expedite delivery when nonreassuring fetal
testing is noted during the second stage of labor.
OBSTETRIC PRACTICE CHANGERS 2014
Hypertension and pregnancy and preventing the first cesarean deliveryA peer-to-peer audiocast 
John T. Repke, MD, author of the June Guest Editorial titled "Low-dose aspirin and preeclampsia prevention: Ready for prime time, but as a 're-run' or as a 'new series'?" recently sat down with Errol R. Norwitz, MD, PhD, fellow OBG Management Board of Editors Member and author of this month’s "Update on Operative Vaginal Delivery." Their discussion focused on individual takeaways from ACOG’s Hypertension in Pregnancy guidelines and the recent joint ACOG−Society of Maternal-Fetal Medicine report on emerging clinical and scientific advances in safe prevention of the primary cesarean delivery.
From their conversation:
Dr. Repke: About 60 recommendations came out of ACOG’s Hypertension in Pregnancy document; only six had high-quality supporting evidence, and I think most practitioners already did them. Many really were based on either moderate- or low-quality evidence, with qualified recommendations. I think this has led to confusion.
Dr. Norwitz, how do you answer when a clinician asks you, “Is this gestational hypertension or is this preeclampsia?”
Click here to access the audiocast with full transcript.
DO NOT SWITCH INSTRUMENTS
Fong A, Wu E, Pan D, Chung HJ, Ogunyemi DA. Temporal trends and morbidities of vacuum, forceps, and combined use of both [published online ahead of print April 9, 2014]. J Matern Fetal Neonatal Med. doi:10.3109/14767058.2014.904282.
In trained hands, operative vaginal delivery can be an extremely effective intervention to expedite delivery in the setting of nonreassuring fetal testing (“fetal distress”) in the second stage of labor. It takes just a few minutes to perform and can avert a frantic dash to the operating room for an emergent cesarean delivery. What to do then in a situation where the vacuum extractor keeps popping off, the vertex is at +3/+5 station, and the fetal heart rate has been at 80 bpm for 8 minutes? It is extremely tempting to discard the ventouse and grab the forceps. But would that be the right decision?
Related article: Is the rate of progress the same for induced and spontaneous labors? William F. Rayburn, MD, MBA (Examining the Evidence; November 2012)
Details of the study
Earlier studies suggested that the combination of vacuum and forceps is associated with an increased risk of fetal injury. Whether this is also true of injury to the mother was not known. To address this issue, Fong and colleagues performed a retrospective cohort study of all successful operative vaginal deliveries identified using ICD-9 procedure codes in the California Health Discharge Dataset from 2001 through 2007. Maternal outcomes were compared between the 202,439 fetuses delivered by vacuum extraction (reference group), 13,555 fetuses delivered by forceps, and 710 fetuses delivered using a combination of the two methods.
Using multivariate analysis modeling, Fong and colleagues demonstrated that, when compared with the vacuum alone, the combined use of vacuum and forceps was associated with significantly higher odds of:
- third- and fourth-degree perineal lacerations (adjusted odds ratio [aOR], 2.86; 95% confidence interval [CI], 2.43–3.36)
- postpartum hemorrhage (aOR, 1.81; 95% CI, 1.33–2.46)
- operative delivery failure (aOR, 2.81; 95% CI, 2.27–3.48).
Related articles:
• Develop and use a checklist for 3rd- and 4th-degree perineal lacerations. Robert L. Barbieri, MD (Editorial; August 2013)
• Postpartum hemorrhage: 11 critical questions, answered by an expert. Q&A with Haywood L. Brown, MD (January 2011)
Fortunately, combined vacuum/forceps deliveries are uncommon, comprising only 0.33% of operative deliveries in this cohort.
Despite the large dataset used, the study was underpowered to examine the effect of combined vacuum/forceps on the incidence of rare events, such as pelvic hematoma, cervical laceration, thromboembolism, and maternal death.
What this EVIDENCE means for practice
The message is clear: Avoid combined vacuum/forceps deliveries. Choose your initial instrument with care because a failed operative vaginal delivery means a cesarean. You don’t get to choose again. The American College of Obstetricians and Gynecologists also recommends against using multiple instruments “unless there is a compelling and justifiable reason.”1
