CHANGES IN PLASMA NON ESTERIFIED FATTY ACIDS AND SERUM GLYCEROL IN PREGNANCY

Summary

Changes in plasma nonesterified fatty acids (NEFA) and serum glycerol in pregnancy were examined in a semi-serial study of 85 women. A preliminary study showed that it was almost impossible to achieve standardized conditions for sampling, and the compromise of taking a single venous sample without stasis, after 30 minutes rest and about 12 hours fasting, was adopted. Although there were large individual variations the patterns of change were, in general, the same for NEFA and glycerol although the two were not closely correlated. There was no convincing change before 30 weeks of pregnancy but both increased in the last ten weeks, fell sharply in the first week post partum, and then rose again to late pregnancy levels by 6 weeks post partum before falling to non-pregnant levels by between 3 and 6 months post partum. Those patterns of change are in broad accord with changes of fat storage and lipolysis associated with the reproductive cycle. Changes in the patterns of NEFA were trivial; the only significant alteration was a small rise in the proportion of C16:O (palmitic) in late pregnancy.