Mode of delivery and the lecithin/sphingomyelin ratio

• Published in: British journal of obstetrics and gynaecology Vol. 86; no. 12; p. 965
• Main Authors: Callen, P, Goldsworthy, S, Graves, L, Harvey, D, Mellows, H, Parkinson, C
• Format: Journal Article
• Language: English
• Published: England 01.12.1979
• Subjects: Amniotic Fluid - analysis; Cesarean Section; Delivery, Obstetric; Female; Humans; Infant, Newborn; Labor, Induced; Pharynx - analysis; Phosphatidylcholines - analysis; Pregnancy; Respiratory Distress Syndrome, Newborn - metabolism; Sphingomyelins - analysis; Time Factors
• ISSN: 0306-5456
• DOI: 10.1111/j.1471-0528.1979.tb11245.x

Babies born by elective Caesarean section are more likely to develop the respiratory distress syndrome that babies born vaginally. We studied the amniotic fluid and pharyngeal lecithin/sphingomyelin (L/S) ratios in three groups of babies born at term: 20 were delivered vaginally after elective induction of labour; 20 were delivered by elective Caesarean section; and 14 by Caesarean section after spontaneous onset of labour. Babies born after induction of labour had higher pharyngeal L/S ratios than babies born by elective Caesarean section. Those born by Caesarean section after spontaneous onset of labour had significantly higher pharyngeal L/S ratios than those in both of the elective delivery groups. There were no significant differences in the amniotic fluid L/S ratios of the two groups who underwent elective delivery. Regression analysis showed a significant relationship between length of labour and increase in the L/S ratio. These results indicate that, during labour, there is a release of fetal lung surfactant into the airways.