Background and Aims Elevated 17-Hydroxyprogesterone [17-OHP] levels in preterm infants are often false positives. We theorized the elevation was related to preterm labor [PTL] and not related to maternal or fetal disease. We surmised that an elevated fetoplacental 17-OHP is akin to obstetrical therapy with progesterone to prevent preterm birth.
Methods Infants with congenital adrenal hyperplasia were excluded. Nucleated red blood cell count [nRBC] was a marker of chronic fetal hypoxia or severe preeclampsia and C-reactive protein [CRP] was an indicator of perinatal infection. Using an effect size of 0.5 with a two-tail test, an alpha of 0.05, and a power of 0.8, at least 66 infants were needed for this study.
Results Fifty-three male and 47 female infants had a mean gestational age of 32.4 and 31.2 weeks, respectively. No mothers received therapy with progesterone for PTL; however, 84% of mothers had PTL. Pearson’s correlation showed lower birth weight (r=–0.65, p<0.001), gestational age (r=–0.64, p<0.001), and one minute APGAR scores (r=–0.21, p=0.04) were significantly associated with increased 17-OHP levels. There was no correlation between CRP or nRBC and 17-OHP levels. After an initial elevated 17-OHP, repeat testing was normal.
Conclusions Intrapartum infection and preeclampsia did not correlate with elevated 17-OHP levels as previously reported. An elevated 17-OHP in preterm infants is associated with PTL and birth. Whether an elevated 17-OHP level at birth confers protection to preterm infants from morbidity or death requires additional investigation.