Abstract & Commentary
In December, a group from Austria published a report evaluating outcomes of infants presenting at term with breeches whose mothers were scheduled to have either an elective cesarean section or a planned vaginal birth. The study group included 699 pregnancies delivered in 1 hospital between January 1993 and December 1999. Patients whose fetuses were between 2500 and 4000 grams, who were in a frank breech position with maternal pelves of adequate size were offered a planned vaginal delivery. Outcomes in this group were compared with those in breech fetuses born during the same time period by planned cesarean section.
Outcome variables included serious neonatal morbidity (birth trauma, seizures, hypotonia, Apgar scores of < 4 at 5 minutes, cord blood acidosis, prolonged intubation, or simply > 4 days in the Newborn Special Care Unit). Pediatric follow-up was possible in 635 children (91%), at an average of 57 months.
Of the 699 term breeches, 218 (31%) had planned cesarean sections. Of the 481 (69%) scheduled to have a vaginal delivery, 342 (71%) did and 139 (29%) eventually had a cesarean section because of CPD, fetal heart abnormalities, or prolapse cord.
Giuliani and colleagues chose an "intention to treat" method to analyze the data. There were no perinatal deaths in either group. Serious perinatal morbidity occurred in 11 fetuses (2.3%) in the planned vaginal group and 1 (0.5%) in the cesarean group. However, the results were not statistically significant. The cord blood pH was statistically lower in the vaginal group (7.23 vs 7.26). There were slightly more cord pHs below 7 (1.5% vs 1.0%) and base deficits above 15 (1.2% vs 0%) but neither was statistically significant, and there were no cases where both pH and base deficit were low.
Developmental delay occurred in 8 of 432 (1.9%) children studied in the vaginal group and 1 of 190 (0.5%) in the cesarean section group, but also this did not obtain statistical significance. Interestingly, of the 10 children able to be studied at 33 months, deemed earlier to have had "serious neonatal morbidity" at birth, none had long-term sequelae.
Giuliani et al’s conclusion was that "planned vaginal delivery remains an option for selected term breech presentations." (Giuliani A, et al. Mode of delivery and outcome of 699 term singleton breech deliveries at a single center. Am J Obstet Gynecol. 2002;187:1694-1698.)
Comment by John C. Hobbins, MD
The now famous study by Hannah and associates1 was the cover story reviewed in a previous OB/GYN Clinical Alert.2 This very large randomized trial involved 121 centers in many countries and included more than 2000 patients randomly allocated to have an elective cesarean section or a planned vaginal delivery. Their results strongly suggested the benefit from cesarean section. For all the reasons stated in the previous OB/GYN Clinical Alert, this represented a bombshell, and, not surprisingly, it generated responses critical of the study design and conclusions rendered. The methodological problems involved low recruitment rate, surprisingly low infant mortality rates in hospitals in the underdeveloped countries which were similar to results from countries with intrinsically low perinatal mortality rates, and the inclusion of perinatal deaths that seemed to have nothing to do with the route of delivery.
Now we have a study indicating no statistically significant difference in outcomes (with the exception of cord pH) in infants scheduled for vaginal delivery. However, the study falls short of being the "be all and end all" of studies addressing this issue.
First, it is not a randomized trial. Second, when knit-picking through the study, I came up with different numbers for cases fitting Giuliani et al’s definitions for serious neonatal morbidity. Last, in every category evaluated there appears to be fewer neonatal problems in the cesarean group (although not significant), and I doubt that there are adequate numbers in the study to allow the statistical power to say that there might not be a difference.
The only significant difference in any of the variables (in cord pH) probably can be explained by the fact that 62 patients in the planned cesarean delivery group required an emergency cesarean section (53 for fetal heart rate abnormalities and 9 for prolapsed cord). Rightfully so, the intention-to-treat analysis assigned these cases to the vaginal group, since this "goes with the territory."
So where do we go from here? To me, the decision of whether or not to deliver all breeches by cesarean section should not be based on either study because of the inherent problems in design, which were beyond Giuliani et al’s controls. One has to weigh the possible benefit of a very modest decrease in perinatal morbidity (and probably not mortality in US hospitals) against the potential increase in maternal morbidity and cost of a cesarean section. For example, the Austrian study showed that 71% of patients in the vaginal delivery group were spared from a cesarean section.
Today this decision is best made by the patient who must be fully informed of the facts available as well as the unknowns regarding the risks and benefits of each option.
Unfortunately, I am very pessimistic that an ideal study can be launched now to accurately answer our patients’ questions.
Dr. Hobbins is Professor and Chief of Obstetrics, University of Colorado Health Sciences Center, Denver.
References
1. Hannah ME, et al. Planned caesarean section versus planned vaginal birth for breech presentation at term: a randomised multicentre trial. Term Breech Trial Collaborative Group. Lancet. 2000;356:1375-1383.
2. Hobbins J. Is cesarean section safer for breeches than vaginal delivery? OB/GYN Clinical Alert. 2001;17: 73-74.
In December, a group from Austria published a report evaluating outcomes of infants presenting at term with breeches whose mothers were scheduled to have either an elective cesarean section or a planned vaginal birth.You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
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