Objective: To investigate whether umbilical cord serum lipid levels differ with mode of delivery.
Design: Retrospective observation study.
Population: Two hundred and ninety mothers aged 29.1 years (SD 4.7) who had vaginal delivery, and 44 mothers aged 30.4 years (SD 4.7) who had elective caesarean section were enrolled.
Main outcome measures: Maternal and umbilical cord blood were obtained immediately after delivery. Serum lipid levels including total cholesterol, high density lipoprotein cholesterol, saturated fatty acid, mono-unsaturated fatty acid and polyunsaturated fatty acid were measured. Obstetric variables and serum lipid levels were compared between the two groups. In each group the correlations of fetal serum lipid levels with maternal serum lipid levels were investigated.
Results: There were no significant differences in maternal age, neonatal weight, gestational duration, placental weight and neonatal gender distribution between the two groups. Only the two fetal serum lipid levels (including total cholesterol and non-high density lipoprotein cholesterol) showed a correlation with maternal fetal lipid levels with correlation coefficients > 0.3 in the caesarean section group. However, saturated fatty acid, mono-unsaturated fatty acid and total fatty acid levels in the non-high density lipoprotein low density lipoprotein, very low density lipoprotein, intermediate density lipoprotein and free fatty acid fraction in the umbilical cord serum were significantly higher in the vaginal delivery cases (P < 0.01).
Conclusions: Umbilical cord serum levels of saturated and mono-unsaturated fatty acids increase during vaginal delivery.