Comparative analysis of perinatal outcomes among different typesof deliveries in term pregnancies in a reference maternity of Southeast Brazil

Summary

Objective:
To compare the perinatal outcomes of women undergoing an elective cesarean section (CS) with those who had an emergency CS during the labor.

Design:
Retrospective cohort study.

Setting:
Hospital Estadual Azevedo Lima (HEAL), Niteroi, Brazil.

Methods:
We analysed elective CS, emergent CS and vaginal delivery as dependent variables and neonatal data (admission in intensive care unit) as independent variables. Using the Statement of Live Birth during a three-month period, all patients who had their children after 38 complete weeks of pregnancy were selected. χ² test and Student t-tests were applied to compare the groups.

Results:
When patients who had vaginal delivery were compared with those who had an elective CS, we observed 219 normal deliveries with 1.8% of hospitalizations in neonatal intensive care units (NICU), and 88 patients of elective CS with 2.3% of admissions in closed units (p = 0.401). We had a sample of 108 newborns delivered by CS during the labor with 8.3% rate of hospitalization in NICU versus 1.8% of 219 newborns delivered vaginally (p = 0.005).

Conclusion:
The worst perinatal outcomes occurred when emergency CS were performed.

KEYWORDS:
perinatal outcomes, cesarean section, vaginal delivery, emergency, term pregnancy

INTRODUCTION

Although the World Health Association’s recommendation that the cesarean section rate should be 15% [1], cesarean deliveries have increased significantly among women of all ages, races and gestational ages in the last 20 years [2]. In the United States, for instance, one third of deliveries are by cesarean and there is a particular national concern about the ever growing number of primary cesarean section rates [3]. In Brazil, the excessive use of cesarean sections is also a serious problem, and the rates are usually above 40% [10]. In some regions, especially in private sector, these rates may reach 80%, for many reasons, from medical indications to maternal request [9].

All over the world, there is a wide range of appropriate maternal and obstetrical indications for primary cesarean delivery. One of the most common is the relatively subjective diagnosis of dystocia [11]. For most pregnancies, which are low-risk, cesarean delivery appears to pose greater risk of maternal morbidity and mortality than vaginal delivery. It also increases the risk of adverse neonatal outcomes like neonatal intensive care unit admissions [4]. Studies have revealed a double rate of transfers to neonatal care units and risk of pulmonary disorders in cases of elective cesarean deliveries [6]. Negative neonatal outcomes such as lower Apgar scores and greater requisition of respiratory assistance tend to be worse when cesarean section is performed in an emergency situation [7].

The purpose of this study was to examine perinatal outcomes among pregnant women who underwent elective and emergency cesarean delivery in the context of a public hospital in Brazil

MATERIALS AND METHODS

The present survey was a retrospective cohort that aimed to analyze the following dependent variables: elective cesarean section, emergent cesarean section and vaginal delivery. Independent variables were neonatal data (admission in intensive care unit). The study was approved for the Research Ethics Committee of Federal University of Fluminense (UFF), Niteroi, Brazil.

Patients were recruited from the maternity of Hospital Estadual Azevedo Lima (HEAL), Niteroi, Brazil. This hospital is responsible for providing health care for pregnant women at low and high risk originated from a wide surrounding area, including other cities. In addition, it accounts for approximately 250 deliveries per month, with a cesarean section rate of 50%.

The patients were selected through their newborn registries. The newborns’ registries were selected from July to September of 2011, excluding those born before 38 weeks of gestation and cases of stillbirth, multiple pregnancies, maternal pathological conditions and fetal anomalies. Cesarean sections indicated due to fetal conditions were also excluded (fetal distress, for instance). Data was collected from medical records available in books at the hospital.

The study data were recorded in an Excel 2007 spread sheet (Microsoft Corp., Redmond, WA, USA). Statistical analysis was performed using SPSS version 13.0 (SPSS Inc., Chicago, IL, USA). Chi-Square (χ2) and t-Student tests for independent variables were applied, considering significance level (p) < 0.05

RESULTS

In the period analyzed, 4272 patients were evaluated at the Obstetric Sector of the Hospital, and 991 admitted. The total number of deliveries was 673. Cesarean sections accounted for 366 deliveries and vaginal births for 307. A sample of 459 patients had their newborns after 38 weeks. Exclusion criteria were found in 44 patients: 25 cases of preeclampsia, 2 with other hypertension syndromes, 24 cases of fetal distress and 1 of diabetes mellitus. In 12 cases there were no available data regarding the indication of the cesarean section.

Concerning the descriptive characteristics of the sample, most of it was composed by young women between 18 to 29 years (70%) and women who had 1 or 2 pregnancies (74%). From 415 patients included, 196 were submitted to cesarean section (cesarean rate of 47.2%), 88 elective and 108 indicated during the labor (emergency cesarean). 219 patients had vaginal delivery. The elective cesarean sections occurred because of: breech presentation, HIV infection, repetition of the cesarean after a prior cesarean, post term pregnancies (after 41 weeks) and preterm rupture of membranes. On the other hand, the indications of emergent cesarean deliveries were: fetal distress, cephalopelvic disproportion and non-progressive labor.

When comparing both groups submitted to cesarean delivery, the mean maternal age was 26 yeas (± 6 years) in the elective and 23 years (± 6 years) in the emergency group (p = 0.001). Furthermore, the mean gestational age was 276 days (± 8) for elective group and 278 days (± 7) for the emergent one. Regarding the birth weight, it was 3282g (± 518g) for the first group and 3348g (± 460g) for the second. There were no differences between the first minute Apgar score in both groups (p = 0.12) and nor the fifth minute Apgar score (p = 0.583). However, the Capurro index was different: 277 days (± 10) for elective cesareans and 280 days (± 7) for emergency cesareans.

Considering the admissions in neonatal intensive care units, the rate was 1.8% among patients of vaginal delivery, 3.4% in the elective cesarean section group and 8.3% in the emergent cesarean section group. The comparison between vaginal and elective cesarean deliveries did not reveal statistical difference (p = 0.401). However, when comparing vaginal deliveries with emergency cesareans, there was a higher admission rate in the second group (p = 0.005) (Table 1)

DISCUSSION

The present survey was based on the study of Kolås et al. [6], which compared elective and emergency cesareans with vaginal deliveries. In this study, planned cesarean delivery doubled the rate of transfers to neonatal intensive care unit and the risk for pulmonary disorders. In our study, there were no significant differences in admissions in neonatal intensive care units between the groups of vaginal and elective cesarean sections.

On the other hand, secondary results from a multicentre prospective cohort revealed that among nulliparous women at near term, the composite maternal and neonatal morbidity is significantly linked with the indication of the cesarean section, with acute clinical emergency cesarean sections carrying the highest risk for morbidity [5]. Our survey agreed with these findings in terms of perinatal outcomes, given that the number of transfers to neonatal intensive care units was higher in the patients who underwent an emergency cesarean section. There seems to be consistency in medical literature that emergency cesarean deliveries may be adding maternal and perinatal adverse outcomes [7].

Regarding the admissions in neonatal intensive care units, we observed higher incidence in the emergency cesarean group. Pacher et al. [8] assessed the perinatal outcomes of pregnant women with pre-eclampsia according the type of cesarean (elective or emergency). In these patients, the Apgar score at 5 and 10 minute was significantly increased in cases delivered by emergency cesarean. No significant difference was observed in the rate of neonatal intensive care unit admissions between the groups (pre-eclamptic with elective cesarean, pre-eclamptic with emergency cesarean, normotensive with elective cesarean and normotensive with emergency cesarean).

CONCLUSION

The conclusion of the study is that there were no differences between perinatal outcomes in women submitted to vaginal and elective cesarean deliveries. However, the rates of neonatal complications were significantly higher in the group of emergency cesarean sections. Our study provides updated data that may be useful for counseling pregnant women with regard to delivery options.

Prof. Edward Araujo Júnior, PhD

Department of Obstetrics, Paulista Schoolof Medicine – Federal University of São Paulo(EPM-UNIFESP)

Rua Belchior de Azevedo, 156, apto. 111 Torre Vitoria

São Paulo – SP, Brazil

CEP 05089-030

e-mail: araujojred@terra.com.br