Abstract 1396 Poster Session IV, Tuesday, 5/4 (poster 71)

Insulin-like growth factor-II (IGF-II) has been widely implicated as a major regulator of fetal growth with cord plasma concentrations correlating directly with birth weight. Smoking during pregnancy is an important risk factor responsible for intrauterine growth retardation but it is not known how this may be related to the regulatory role of IGF-II. We compared IGF-II concentrations in human cord plasma of healthy term babies whose mothers had a history of smoking for at least two months prior to delivery. Smoking was verified by measurements of cotinine concentrations in maternal hair using a commercial ELISA. Plasma IGF-II was determined by RIA. Hair cotinine concentrations in the group of mothers (n = 11) smoking more than 15 cigarettes/day were 5.13 ± 1.46 ng/mg hair (range 2.38 - 6.44) and were nearly 20 times higher compared to the non-smoking group (0.27 ± 0.16 ng/mg hair, range 0.0 - 0.89, n = 14). Birth weight in the smoking group was 3050 ± 413 g and 3499 ± 440 g (p = 0.048) in the control group. Cord plasma IGF-II concentrations in the smoking group were 29.9 ± 5.7 nM (range 20.9 - 37.0) and significantly lower compared to the non-smoking group (41.6 ± 3.2 nM, n = 27, range 36.5 - 47.3; p = 0.047). These findings indicate that chronic exposure to cigarette smoke during pregnancy is associated with reduced concentrations of IGF-II in cord plasma and may thus be implicated in the pathophysiology of cigarette smoke-related fetal growth retardation.