Insulin-like growth factor-1 in pregnancy

Abstract

Objective: To study the relationships between plasma insulin-like growth factor-1 (IGF-1) concentrations and birth weight, current weight and other constitutional factors among healthy, nulliparous women aged 19–25 years. Design and methods: Forty healthy female university students aged 19–25 years volunteered for this study. They had never been pregnant and were not using oral contraceptives (OCs). Blood samples were drawn both in the follicular and luteal cycle phases (08:00–10:00 h) and weight, height, and waist–hip ratio were measured at the same time by one person (H.J). Information regarding age, birth weight, OC use, etc. was obtained from a questionnaire filled out by the women. Plasma IGF-1 concentrations were analyzed by radio immunoassay. Results: In a multivariate model including birth weight, current weight and age, IGF-1 was significantly inversely associated with birth weight in both cycle phases, while current weight was positively associated with IGF-1 in both cycle phases although only significantly so in the follicular phase. IGF-1 concentrations in both cycle phases showed a non-significant decrease with age. Conclusion: In this group of 19–25-year-old healthy nulliparous women IGF-1 displayed a significant inverse association with birth weight in both cycle phases given that the current weight was adjusted for, while current weight was positively related to IGF-1 concentrations.