Maternal-neonatal amino acid blood levels in relation to the mode of delivery

Acta Obstet Gynecol Scand. 2009;88(1):71-6. doi: 10.1080/00016340802578098.


Objective: To investigate the effect of the mode of delivery on maternal-neonatal amino acid levels as high blood levels of some amino acids are implicated with endurance exercise.

Design: Comparative study.

Sample: Thirty women in normal pregnancy divided into two groups: Group A (n=15) with normal labor and vaginal delivery and group B (n=15) with scheduled cesarean section.

Material and methods: Blood was obtained from the mothers pre- versus post-delivery as well as from the umbilical cord. Routine laboratory tests (liver enzymes, muscle enzyme, etc.) and the amino acid blood levels were measured with a clinical chemistry analyzer and tandem mass spectrometry methods, respectively.

Results: Routine laboratory tests and the amino acid blood levels were similar in the two groups of mothers pre-delivery. Total antioxidant status levels were reduced, whereas the branched-chain amino acids (BCAAs) and alanine levels were remarkably elevated in the sera of group A post-delivery, whereas they remained unaltered in group B at the same time of study. The mentioned BCAAs and alanine levels were higher in the umbilical cord blood of group A than those in group B. The rest of the amino acids were similar.

Conclusions: The increased BCAAs and alanine blood levels in mothers of group A may be related to uterine and skeletal muscle contractions during the vaginal delivery process and the high levels in the umbilical cord blood of their neonates may mirror those of the mothers. The elevation of BCAAs both in mothers of group A and their neonates may exclude or minimize tyrosine and tryptophane levels from entry in the brain resulting in decreased biogenic amine and increased prolactin production in the central nervous system of these mothers and their infants.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Amino Acids, Branched-Chain / blood*
  • Antioxidants / metabolism*
  • Biomarkers / blood
  • Cesarean Section / methods
  • Cohort Studies
  • Delivery, Obstetric / methods*
  • Female
  • Fetal Blood / chemistry*
  • Gestational Age
  • Humans
  • Infant, Newborn
  • Mass Spectrometry
  • Postpartum Period
  • Pregnancy / blood*
  • Pregnancy Outcome
  • Prenatal Care / methods
  • Probability
  • Sensitivity and Specificity
  • Term Birth
  • Young Adult


  • Amino Acids, Branched-Chain
  • Antioxidants
  • Biomarkers