This study is one of the few studies to analyze, in a large sample, the difference in outcome between breech VD and breech CD in a low-income country. During the study period, there was an almost threefold increase in breech CDs. The risks of perinatal death and moderate asphyxia were significantly higher among infants delivered vaginally; and for perinatal death, they were higher if the mother had been referred, irrespective of parity, BW, insurance status, and delivery year. Despite the increase in breech CDs, overall perinatal mortality in breech births did not decrease as there was an increase in stillbirths among vaginally delivered breech babies.
In agreement with earlier studies, the present study shows improved fetal outcome for breech fetuses, in terms of intrapartum deaths, early neonatal deaths, and asphyxia, when delivered by CD compared to VD [1, 2, 4, 8]. Results from other, similar settings do not, however, completely agree with our findings. Studies from Guinea and Nigeria found low Apgar scores to be more frequent among VD than CD for breech presentation [12, 13, 18] although the Guinean study showed no difference in PMR between the groups . As in our study, a study from Zimbabwe demonstrated a significant reduction in PMR for breech presentation (OR 5.4, p < 0.001), but saw no correlation between changes in CD rate and PMR . In 2006, a Nigerian study showed a significant reduction in PMR for infants of primigravidae with BW > 3,500 g when delivered by CD compared to VD .
The almost threefold increase in CD rate for breech presentation was not associated with an overall improvement in breech births or improved survival for breech-delivered infants. This is contrary to the TBT study and other studies in Western settings [1, 8, 19, 20]. One explanation, at least a partial explanation, for this difference might be selection bias, as there was a gradual improvement in maternity care in Dar-es-Salaam as the surrounding district hospitals improved . Muhimbili National Hospital had a 40 % decrease in deliveries between 2000 and 2002 and between 2009 and 2011, which was concomitant to an increase in referral cases, from 7 to 28 % . The higher proportion of referred patients also includes patients with breech presentation in labor, and they had worse outcome, irrespective of mode of delivery. Another reason for this difference could have been reduced staff skills in assisted breech delivery, as, in our sample, the number of vaginal breech deliveries decreased from three per week to one every 2 weeks . Van Roosmalen and Meguid highlight that settings that increasingly use CD may not have trained staff with the skills to assist vaginal breech delivery, and that this staff will need skills training in this area . Hannah et al. found that planned CD for breech presentation did not reduce serious morbidity in newborns in high-PMR countries as much as in low-PMR countries. They recognized the possibility of the caregivers being more experienced in breech deliveries in the low-PMR countries, which traditionally have low CD rates .
It is unclear how selection for the two different modes of delivery in this study was carried out. Women who delivered vaginally might have represented good candidates for a trial of labor, although facilities for such assessments are not the same at MNH as in a facility in a high-income country. Lead time from decision to operate can in this low-income setting be extended by several hours , meaning that VDs could represent a group of most urgent cases that did not make the necessary conversion to CD. This might be one explanation for the clustering of VD stillbirths, indicating the difficult conditions prevailing in this setting, especially as the study sample comprised of presumed intrapartal deaths. Birth asphyxia was the cause of neonatal death for all CDs and nine out of ten VDs.
Mothers with private insurance had excellent reported perinatal outcomes, which might indicate socioeconomic disparities and/or different quality of care. However, they constituted only 6 % of the sample, and did not influence the overall results.
As expected, women with CD suffered from hemorrhage more often, and one out of 25 had significant blood loss. One maternal death was caused by anesthetic complications. We had no information about postoperative complications such as rupture of the wound, infection, thromboembolism, or readmissions. Lack of registrated postpartum complications is a major weakness of the study as it makes it difficult to properly evaluate risks connected to CD. In high-income settings, 17 % of CDs may be complicated by maternal infectious morbidity ; the TBT study found a postpartum systemic infection rate of 1.5 % and a wound infection rate of 1.5 % for CD . However, Litorp et al. report, in a study conducted at MNH in 2012 and published in 2014, an overall CD complication risk per 1,000 operations for maternal death of 1.0 (0.1–3.6) and for life-threatening complications of 6.0 (3.1–10) . Based on these figures, two to four cases of life-threatening complications among CDs in this study could have occurred in this sample .
Consideration of complications is important when assessing indications for CD in developing countries and these should be weighed against the benefits of operation. The risk of uterine rupture is increased by up to 35 times for women in labor who have had a previous CD, compared to no history of CD . Placenta accreta is three times more common in women with previous CD . However, neither short-term complications after discharge nor long-term outcome could be addressed in this study.
In a cost-effectiveness analysis of strategies for maternal and neonatal health in developing countries, CD performed for breech presentation, obstructed labor, and fetal distress in conjunction with emergency neonatal care was estimated to be cost-effective in East African and South East Asian countries . A cost analysis of hospital deliveries in low-PMR countries that was conducted in 2006 reports that, with regard to breech presentation, CD was less expensive compared to VD (US$7,165 versus US$8,042) .
Concerns about the increasing CD rates in low-income countries have been raised [4, 6, 10, 16, 27], although breech presentation represents a small percentage (1.7 %) of indications for CD at MNH and although breech benefits from CD [1, 4, 11, 12, 25]. Vaginal delivery of breech presentation still remains an option and the systematic review by Berhan et al. supports “the practice of individualised decision-making on the route of delivery” .
One strength of this study is its unique database: All the deliveries were performed in a busy University Hospital in a low-income setting. However, the database has limitations. There may have been underreporting of breech deliveries. Also, it was not possible to determine whether the decision to perform CD was made before or during labor; this could not be analyzed because the variable “elective/emergency” was missing in 75 % of cases. Most of the decisions to perform CDs were probably made during labor, which may explain the high mortality and morbidity rate related to CD in this setting.
We were unable to describe early neonatal mortality. Discharge is normally 6 h after a VD and 3 days after a CD, so the rate of neonatal deaths may have been underestimated, especially among the VD cases.