Peripheral blood level of 17-hydroxyprogesterone in neonates and influencing factors

Abstract

Objective To determine the peripheral blood level of 17-hydroxyprogesterone (17-OHP) in neonates and to analyze its influencing factors. Methods All newborns (n=18 461) born in Fujian Maternity and Child Health Care Hospital from November 1, 2012 to January 31, 2014 were included in this study, except for those with congenital adrenal hyperplasia. Heel prick blood samples were collected after 72 h after birth for determination of 17-OHP by time resolved fluorescence immunoassay. All subjects were grouped according to different factors such as gender, mode of delivery, gestational age, birth weight, number of pregnancies, time of blood sampling and whether to be hospitalized. While 2 997 inpatients among them were grouped according to blood glucose level, acid-base equilibrium, and levels of electrolytes, respectively. The level of 17-OHP was analyzed with Mann-Whitney U test, Kruskal–Wallis H test and multiple linear regression. Results The level of 17-OHP in these newborns ranged from 0.0 to 196.0 nmol/L with a geometric mean (GM) of 5.7 (5.6-5.8) nmol/L. The GM level was higher in male group (n=10 026 ) than in female group (n=8 435) [6.1 (6.0-6.2) vs 5.4 (5.2-5.5 ) nmol/L, Z=-10.65, P<0.05]; higher in cesarean delivery group (n=7 014) than in vaginal delivery group (n=11 447 ) [6.2 (6.0-6.3 ) vs 5.5 (5.4-5.6) nmol/L, Z=-10.88, P<0.05]; higher in multiply pregnancy group (n=656) than in singleton pregnancy group (n=17 805) [8.7 (8.2-9.3) vs 5.6 (5.6-5.7) nmol/L, Z=-14.21, P<0.05]; higher in inpatient treatment group (n=2 997 ) than in outpatient treatment group (n=15 464) [8.0 (7.7-8.4) vs 5.4 (5.3-5.5) nmol/L, Z=-27.63, P<0.05]. Significant difference was found in 17-OHP level among the eight groups with different gestational age, seven groups with different birth weight and five groups with different age at sampling (χ2=2 409.25, 1 510.30 and 636.60, all P<0.05). Further analysis showed that the 17-OHP level deceased with the increasing birth weight (if less than 4 000 g), with the increase of gestational age (if ≥29 weeks), and with the growth of the babies (from day 3 after birth to day 5). Among the 2 997 inpatients, higher 17-OHP level was found in the acid-base imbalance group than in the acid-base equilibrium group [9.7 (8.6-10.8) vs 7.0 (6.3-7.7) nmol/L, Z=-6.21, P<0.05], and higher in the electrolyte disturbance group than in the electrolyte balanced group [9.4 (8.5-10.3) vs 7.9 (7.5-8.3) nmol/L, Z=-4.49, P<0.05]. The 17-OHP level in the hypoglycemia and hyperglycaemia group than in the euglycemia group respectively [9.7 (9.1-10.4) and 8.1 (7.6-8.6) vs 8.6 (6.7-11.1) nmol/L, Z=-4.18 and -2.11, both P<0.05]. The R2 value of gestational age, birth weight and glucose were 0.200, 0.115 and 0.080 respectively. Multivariate linear regression analysis showed that 17-OHP was influenced the most by gestational age, followed by birth weight, blood glucose, acid-base balance status, number of pregnancies, electrolytes, mode of delivery, gender and days on blood sampling. Conclusion The peripheral blood level of 17-OHP in neonates is affected by many factors, such as gestational age, birth weight, blood glucose and acid-base equilibrium. Key words: 17-Hydroxyprogesterone; Adrenal hyperplasia, congenital; Infant, newborn