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Delivery of a Second Twin
Abstract & Commentary
By John C. Hobbins, MD, Professor and Chief of Obstetrics, University of Colorado Health Sciences Center, Denver, is Associate Editor for OB/GYN Clinical Alert.
Dr. Hobbins reports no financial relationship to this field of study.
Synopsis: By using an "active" approach to the second stage of labor in second twins, many motivated patients can avoid the need for cesarean section without increased neonatal morbidity.
Source: Fox NS, et al. Active second-stage management in twin pregnancies undergoing planned vaginal delivery in a U.S. population. Obstet Gynecol 2010;115(2 Pt 1):229-233.
In a recent issue of OB/GYN Clinical Alert (see the November 2009 issue), a special feature was devoted to the contemporary antepartum management of twin pregnancies. However, conspicuously absent in this piece was the intrapartum management of twin deliveries. This month's issue of Obstetrics & Gynecology contained a paper that deals with the sometimes troublesome problem of delivering second twins, a discussion of which should now complete the job.
Fox et al undertook a retrospective analysis of 4 years worth of experience of offering an attempted vaginal delivery for a second twin, rather than empirically doing a cesarean section for both, if the second twin was not in a vertex position. The technique of "active management" of the second stage involved adhering to a strict protocol, which included the following types of patients:
The method involved having an epidural in place in the operating room with anesthesia on-site and an operative team poised for a possible cesarean section. The operators were all attendings trained in the techniques to be described. If the second twin settled well into the pelvis, then an amniotomy was performed, and this baby was delivered as a vertex. If the second twin was in a breech presentation, then a breech extraction was undertaken immediately after the first was delivered, with an amniotomy being performed, preferably, after the feet were grasped. If the second twin's head was floating, then a two-handed internal podalic version was attempted with one hand in the vagina/uterus and the other on the abdomen, and the breech was extracted.
Of the 287 patients studied, 157 (54.7%) chose to have an elective cesarean section, and of the remaining 130 patients (43.5%), 85% were successfully delivered by the vaginal route. Interestingly, in the 15% who had to be sectioned, the reasons for an abdominal delivery were based on circumstances presenting prior to delivery of their first twin. In other words, of those who delivered the first twin vaginally, none had to have a cesarean section for the second twin. This also included six patients who had prior cesarean sections.
Most importantly, the ones delivered vaginally had no differences in Apgar scores or cord pH values compared with those delivered by cesarean section.
To underscore the study findings, about half of all patients with twins chose simply to have cesarean sections, rather than to attempt a vaginal delivery for both. The remaining half was clearly motivated to try for vaginal deliveries, and all but 15% of them had their wish. It is interesting that there were no vaginal/cesarean sections in any of these patients and those babies born via the vaginal route had no evidence that the route of delivery was associated with an increase in short-term morbidity.
The results of the study are similar to those of another single-center study,1 but two other studies,2,3 involving pooled data and operators with varying experience, showed a higher perinatal morbidity with this approach. These latter studies led one respected obstetrician to write that internal version is contraindicated since "no one trained after about 1970 has any idea how to perform the maneuver."4 In a way, I agree, since, although some younger obstetricians have been trained to deliver breeches vaginally and could pass the skill on to others (as the authors of the Fox study were and did), the maneuver of moving an unengaged head out of the way and then doing a combined external/internal version is not something with which many obstetricians have had experience. Yet, how is this much different than doing an internal podalic version for a fetus in a transverse lie, followed by an immediate breech extraction?
The authors used the term "second-stage active management" for the second twin, which simply means "Do something right away after the first twin is delivered." In this case, either one would immediately rupture membranes of the second twin if the vertex comes down into the pelvis or, if it does not, go for the feet anyway you can, followed by an extraction. Another option, not addressed in the study for a vertex with a high station, would be to quickly make sure with ultrasound that there is no cord in front of the head, and then to needle the membranes so the head can settle into the pelvis. I would assume that in most cases the second twin could be delivered as a vertex under these circumstances.
Whatever the technique, this paper suggests that with the Fox study's experienced operators, the vast majority of patients with twins wanting vaginal deliveries attained their goal, without apparent neonatal morbidity. However, the "skilled operator" part is extremely important, as pointed out in a companion editorial by Mary D'Alton,5 and, based on contemporary trends, those with this experience are a dying breed.