['The aim of this study was to determine the association between three parameters of second trimester serum secreening and preterm labor and intrauterine growth restriction (IUGR) in patients with hyperemesis gravidarum (HG).', 'A prospective study on 429 pregnancies with HG was designed to determine the association between alpha-fetoprotein (AFP), unconjugated estriol (uE3), human chorionic gonadotropin (HCG) and pregnancy prognosis in terms of preterm labor, IUGR and birth weight.', 'In our study group the mean age of patients was 25.4±3.8 years. Mean birth weight was 3180±555 g. Mean AFP, uE3, hCG levels in the study group were 1.44±0.65 MoM, 0.91±0.38 MoM, 1.09±0.64 MoM, respectively. Twenty nine (6.8%) patients delivered before 37 weeks of gestation and 52 (12.1%) patients developed IUGR. Mean MoM values of AFP among patients with preterm labor, IUGR and normal delivery were 1.35±0.45, 1.97±0.81, 1.34±0.58 MoM, respectively (p<0.001). Mean MoM values of hCG among patients with preterm labor, IUGR and normal delivery were 1.46±0.90, 1.35±0.89, 1±0.5 MoM respectively (p<0.001). Mean MoM values of uE3 among patients with preterm labor, IUGR and normal delivery were 0.75±0.25, 0.80±0.30, 0.95±0.40 MoM, respectively (p=0.003). Odds ratio of AFP>1.55 was 3.73 (95% CI, 1.99-6.98, p<0.001) for IUGR after adjustment for HCG.'] Is second trimester serum alpha-fetoprotein level a significant positive predictor for intrauterine growth restriction in pregnant women with hyperemesis gravidarum?