480 Activity of Cyp3A in Mothers and Their Newborns Using 4B-Hydroxycholesterol as a Marker

Abstract

Background: Pregnancy increases the activity of cytochrome P4503A (CYP3A). These enzymes metabolize several endogenous substances, e.g. cholesterol, which is converted into 4bhydroxycholesterol (4b-OHchol). We have suggested that 4b-OHchol can be used as a marker for CYP3A activity.

Aim: To study the activity in CYP3A in pregnant women and their infants by using 4b-OHchol as a marker.

Methods: 21 women and their 22 newborn infants (one pair of twins) were recruited at the delivery ward at Karolinska University Hospital, Huddinge. Levels of 4b-OHchol were determined in mothers and children from delivery to 72 h postpartum. 14 infants were born vaginally and 8 by elective caesarean section (CS). Follow-up after 3 months was performed in 10 mother-child pairs.

Results: Median levels of 4b-OHchol were increased in pregnant women compared to healthy adults. 3 months after delivery 4b-OHchol was still elevated in women giving birth vaginally. In contrast, women giving birth by CS had normal levels. Children born vaginally had significantly higher levels of 4b-OHchol compared to children born with elective CS, but both groups had lower levels than healthy adults. There was a significant increase in 4b-OHchol levels in both groups after 3 months.

Conclusion: Pregnancy activates the CYP3A enzymes. In newborns 4b-OHchol levels are low, but already after three months the children have CYP3A-activities comparable to that of healthy adults. Children born vaginally have higher levels of 4b-OHchol at birth, than children born with CS.

Log in or create a free account to read this content

Gain free access to this article, as well as selected content from this journal and more on nature.com

Access through your institution

or

Sign in or create an account

Continue with Google

Continue with ORCiD