[UMBILICAL CORD CORTISOL LEVELS DO NOT CORRELATE WITH 17-HYDROXYPROGESTERONE LEVELS IN THE NEWBORN SCREENING TEST]

Cortisol is a stress response marker. During pregnancy and delivery, cortisol levels are elevated, especially in complicated deliveries. Blood cortisol levels can increase 17-hydroxyprogesterone (17-OHP) levels in the mother during delivery, however this effect was not elucidate in newborn infants.

To investigate whether there is a correlation between umbilical cord cortisol and 17-OHP levels in the newborn, leading to false results in the newborn screening tests.

Umbilical cord cortisol levels together with maternal delivery data were analyzed at Meir Medical Center during 2015-2016. The newborn screening test was performed in all newborns at 36 to 72 hours after birth, and data on 17-OHP levels were recorded. A correlation between mode of delivery, umbilical cord cortisol level and 17-OH- P levels of the newborn screening tests was conducted.

A total of 122 newborn infants were included in the study. The mean cord cortisol levels were 12.3±4.1 mcg/dL. Vacuum extraction deliveries were associated with the higher cord cortisol level compared to unplanned cesarean section deliveries, planned cesarean sections and vaginal deliveries (all p<0.03). Unplanned cesarean sections had higher umbilical cord cortisol levels compared to planned cesarean section and vaginal delivery ( all p<0.05). All infants had 17-OHP levels within normal limits (<35 nM), with no correlation to umbilical cord cortisol levels (r=0.012, p=0.26).

Vacuum extraction deliveries are associated with the highest cord cortisol level compared to unplanned cesarean section deliveries and to vaginal deliveries, however, these levels are not associated with high levels of 17-OHP of the newborn screening test. Therefore, our data does not support the hypothesis that stressful deliveries are associated with high false positive 17-OHP levels in the newborn screening test.