Regulation of insulin-like growth factor-I and insulin-like growth factor binding protein-1 concentrations in preterm fetuses

• Published in: American journal of obstetrics and gynecology 2003-02, Vol.188 (2), p.485-491
• Main Authors: Verhaeghe, Johan, Van Herck, Erik, Billen, Jaak, Moerman, Philippe, Van Assche, F.André, Giudice, Linda C.
• Format: Article
• Language: English
• Subjects: Betamethasone - therapeutic use; Biological and medical sciences; Birth Weight; Blood Glucose - analysis; C-Peptide - blood; Delivery. Postpartum. Lactation; Disorders; Female; Fetal Blood; Gestational Age; Glucocorticoids - therapeutic use; Gynecology. Andrology. Obstetrics; Humans; hypoxia; insulin; Insulin-Like Growth Factor Binding Protein 1 - blood; Insulin-Like Growth Factor I - metabolism; Insulin-like growth factors; Medical sciences; Osmolar Concentration; Oxygen - blood; Partial Pressure; placental infarcts; Pregnancy; Pregnancy Trimester, Second; Pregnancy Trimester, Third; Umbilical Arteries; Umbilical Veins
• ISSN: 0002-9378; 1097-6868
• DOI: 10.1067/mob.2003.26

Objective: Our purpose was to evaluate which factors regulate insulin-like growth factor-I and insulin-like growth factor binding protein-1 concentrations in preterm fetuses. Study design: We studied 76 singleton births between 25 and 36 weeks of gestation. Forty-nine pregnancies were complicated by hypertensive disease; 24 pregnancies were complicated by preterm labor or preterm rupture of membranes; and antenatal glucocorticoids were given in 49 pregnancies. Pathology reports showed infarct(s) or hematoma(s) in 31 of 69 placentas. We recorded blood gas values in umbilical artery and vein and measured glucose, C-peptide, and insulin-like growth factor-I and insulin-like growth factor binding protein-1 concentrations in umbilical vein. Results: Birth weight correlated with umbilical vein insulin-like growth factor-I (r = 0.68, P < .0001) and inversely with insulin-like growth factor binding protein-1 (r = −0.26, P = .02). Babies with birth weight of ≤25th percentile had lower insulin-like growth factor-I but higher insulin-like growth factor binding protein-1 levels than babies at >25th percentile. Two-factor analysis of variance showed that umbilical vein insulin-like growth factor-I was determined by gestational age (P = .0004) and birth weight percentile (P < .0001), whereas insulin-like growth factor binding protein-1 was not affected by gestational age. Umbilical vein C-peptide was highly correlated with insulin-like growth factor binding protein-1 (r = −0.55, P < .0001), but not insulin-like growth factor-I, levels. Blood gas values in umbilical artery and vein, particularly umbilical artery PO2, were correlated with umbilical vein insulin-like growth factor-I and insulin-like growth factor binding protein-1 (r = 0.51 and −0.48, respectively; P < .0001); changes in insulin-like growth factor-I and insulin-like growth factor binding protein-1 occurred at umbilical artery PO2