Effect of delivery method on outcomes in the very low-birth weight breech infant: is the improved survival related to cesarean section or other perinatal care maneuvers?
ABSTRACT The perinatal mortality rate among very low-birth weight infants has been decreased by 20% during the last 4 years of the 1973 to 1980 period here reported. The concurrent increase in the cesarean section rate from 11.9% to 49.1% during the same time frames has been assumed to be responsible for the improved outcome. The changes were most marked in the extremely low-birth weight group (less than 1,000 gm). The survival rates and cesarean section rates were examined among infants of similar birth weight and gestational age in the vertex presentation, in the same time frames. A similar or greater reduction in mortality rate (from 85% to 45%) was noted in the very low-birth weight vertex infants, whereas the cesarean section rate remained minimally and not significantly increased (14.2% to 22.2%). The interpretation of this finding is by no means clear but must include the hypothesis that the increased cesarean section rate may be incidental and in no way related to the improved outcome. The most statistically significant determinants of outcome remain birth weight and gestational age strata, with no significant difference in outcomes when the extremely low-birth weight group is analyzed separately from the entire very low-birth weight group. As yet unidentified perinatal care practices, other than cesarean section, may be more likely to affect outcome in this high-risk group.
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ABSTRACT: We examined the associations between Caesarean section and neonatal mortality in singleton liveborn very-low-birthweight (VLBW) infants (500-1499 g) born during 1984-95 in Washington State, USA, using data from the Washington State birth certificate files. The infants included in this study had no life-threatening congenital malformations and had not been delivered by a repeat Caesarean without a trial of labour (n = 5182). For infants weighing 500-749, 750-999, 1000-1249 and 1250-1499 g, the neonatal mortality rates were 57.8%, 18.6%, 9.7% and 4.7%, respectively, and the Caesarean section rates were 28.4%, 47.8%, 48.0% and 44.6%. The adjusted odds ratios (ORs) for neonatal death associated with Caesarean section were 0.55 [95% confidence interval 0.38, 0.78] for the 500-749 g infants (n = 1059), and 1.15 [0.91, 1.45] for the larger (750-1499 g) infants, after adjustment for birth year, type of hospital, birthweight, presence or absence of labour, breech/malpresentation, and other obstetric indications for Caesarean section (prolapsed cord, placenta praevia, eclampsia, pre-eclampsia and chronic hypertension). However, when the larger (750-1499 g) vertex-presenting (n = 3248) and breech/malpresenting (n = 809) infants were considered separately, the adjusted ORs were 1.42 [1.05, 1.91] and 0.37 [0.23, 0.58] respectively. In contrast, among infants weighing 500-749 g, the ORs were not modified by presentation. The results were similar when we restricted analyses to infants without the above obstetric indications for Caesarean section. Because such an observational study is liable to unmeasurable biases and incomplete reporting of obstetric complications, these OR estimates may be subject to residual confounding. In their present state, these recent population-based data support the view that Caesarean sections do not enhance the neonatal survival of larger (> 750 g) VLBW babies when obstetric complications are absent. The possibility of a protective effect of Caesarean section on the survival of breech/malpresenting infants and infants weighing 500-749 g deserves further studies.Paediatric and Perinatal Epidemiology 04/1999; 13(2):170-89. · 2.16 Impact Factor
- Archives of Gynecology and Obstetrics 02/1995; 257(1-4):462-71. · 1.33 Impact Factor
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ABSTRACT: The survival and impairment rates of 276 inborn singleton infants of 23-28 weeks' gestation were reported according to route of delivery and mode of presentation. The Caesarean section rate was 29% overall, ranging from 13% at 25 weeks to 46% at 28 weeks. In the vertex group, no significant difference in survival or impairment rate was found between Caesarean and vaginal births. In the non-vertex group, Caesarean births had a similar survival rate but a significantly lower impairment rate compared to vaginal births. For Caesarean births, no significant difference in survival or impairment rate was found between vertex and non-vertex groups. In contrast, for vaginal births, the mode of presentation was important: the non-vertex group had a significantly lower survival rate and higher impairment rate compared to the vertex group. We found no evidence to support the use of Caesarean section in extremely preterm infants with vertex presentation, except for recognized maternal or fetal indications. The findings in the non-vertex group indicated that there is a definite need for a randomized clinical trial to investigate the possible benefits of Caesarean section in extremely preterm infants with non-vertex presentation.Australian and New Zealand Journal of Obstetrics and Gynaecology 09/1987; 27(3):196-200. · 1.30 Impact Factor