Maternal obesity has been reported as a risk factor for various maternal and fetal complications. The aim of the present study was to examine the patterns of basal and postprandial plasma concentrations of certain gut hormones affecting food intake such as acylated ghrelin, peptide YY(3-36) (PYY(3-36)), cholecystokinin (CCK), insulin and glucose in pregnant women with varying body mass gain during physiological pregnancy. The study included 34 women with singleton pregnancies in the 2(nd) trimester of gestation. The examined pregnant women were divided into 4 groups; I. control pregnancy (CP) with weight gain below 0.5 kg/week; II. overweight low weight gain <1 kg/week (OLWG), III. overweight high weight gain >1 kg/week (OHWG); morbidly obese pregnant with weight gain >1.5 kg/week (MOP). The basal acylated-ghrelin levels in MOP subjects were significantly higher than those in CP and no usual suppression of acylated ghrelin after the meal observed in CP as well as in OLWG and OHWG was found in MOP women. Basal PYY(3-36) plasma levels were similar in CP, OLWG and OHWG but in MOP was significantly reduced and no significant increase in hormone level, typically observed in CP, was detected after a meal in overweight or obese women studied. The fasting CCK and C-reactive protein (CRP) levels in MOP subjects were significantly higher than those in CP and other overweight women. In conclusion, we found that pregnant women with overweight and obesity exhibit significant changes in fasting and postprandial gut hormones affecting food intake such as acylated ghrelin, PYY(3-36) and CCK as well as in CRP and these changes might contribute, at least in part, the development of obesity in pregnancy.