Tomas Prior1, Sailesh Kumar2. 1. Centre for Fetal Care, Queen Charlotte's and Chelsea Hospital, Du Cane Road, London W12 0HS, UK; Institute for Reproductive and Developmental Biology, Imperial College London, London W12 0HS, UK; Mater Research Institute/University of Queensland, Aubigny Place, Raymond Terrace, South Brisbane 4101, QLD, Australia. 2. Centre for Fetal Care, Queen Charlotte's and Chelsea Hospital, Du Cane Road, London W12 0HS, UK; Institute for Reproductive and Developmental Biology, Imperial College London, London W12 0HS, UK; Mater Research Institute/University of Queensland, Aubigny Place, Raymond Terrace, South Brisbane 4101, QLD, Australia. Electronic address: sailesh.kumar@mater.uq.edu.au.
Abstract
OBJECTIVE: Current intra-partum monitoring techniques are often criticized for their poor specificity, with their performance frequently evaluated using measures of the neonatal condition at birth as a surrogate marker for intra-partum fetal compromise. However, these measures may potentially be influenced by a multitude of other factors, including the mode of delivery itself. This study aimed to investigate the impact of mode of delivery on neonatal condition at birth. STUDY DESIGN: This prospective observational study, undertaken at a tertiary referral maternity unit in London, UK, included 604 'low risk' women recruited prior to delivery. Commonly assessed neonatal outcome variables (Apgar score at 1 and 5min, umbilical artery pH and base excess, neonatal unit admission, and a composite neonatal outcome score) were used to compare the condition at birth between babies born by different modes of delivery, using one-way ANOVA and chi-squared testing. RESULTS: Infants born by instrumental delivery for presumed fetal compromise had the poorest condition at birth (mean composite score=1.20), whereas those born by Cesarean section for presumed fetal compromise had a better condition at birth (mean composite score=0.64) (p=<0.001). No difference in composite neonatal outcome scores was observed between babies born by instrumental delivery for a prolonged second stage (no evidence of compromise), and those born by Cesarean delivery for presumed fetal compromise. CONCLUSIONS: Mode of delivery represents a potential confounding factor when using condition at birth as a surrogate marker of intra-partum fetal compromise. When evaluating the efficacy of intra-partum monitoring techniques, the isolated use of Apgar scores, umbilical artery acidosis and neonatal unit admission should be discouraged.
OBJECTIVE: Current intra-partum monitoring techniques are often criticized for their poor specificity, with their performance frequently evaluated using measures of the neonatal condition at birth as a surrogate marker for intra-partum fetal compromise. However, these measures may potentially be influenced by a multitude of other factors, including the mode of delivery itself. This study aimed to investigate the impact of mode of delivery on neonatal condition at birth. STUDY DESIGN: This prospective observational study, undertaken at a tertiary referral maternity unit in London, UK, included 604 'low risk' women recruited prior to delivery. Commonly assessed neonatal outcome variables (Apgar score at 1 and 5min, umbilical artery pH and base excess, neonatal unit admission, and a composite neonatal outcome score) were used to compare the condition at birth between babies born by different modes of delivery, using one-way ANOVA and chi-squared testing. RESULTS:Infants born by instrumental delivery for presumed fetal compromise had the poorest condition at birth (mean composite score=1.20), whereas those born by Cesarean section for presumed fetal compromise had a better condition at birth (mean composite score=0.64) (p=<0.001). No difference in composite neonatal outcome scores was observed between babies born by instrumental delivery for a prolonged second stage (no evidence of compromise), and those born by Cesarean delivery for presumed fetal compromise. CONCLUSIONS: Mode of delivery represents a potential confounding factor when using condition at birth as a surrogate marker of intra-partum fetal compromise. When evaluating the efficacy of intra-partum monitoring techniques, the isolated use of Apgar scores, umbilical artery acidosis and neonatal unit admission should be discouraged.