Cholecystokinin secretion in pregnancy.

The gallbladder volume is increased in pregnancy, and its contraction during a meal is impaired. This is of importance for the increased risk of gallstones in pregnancy, since it may cause retention of cholesterol crystals in the gallbladder lumen. Cholecystokinin (CCK) is responsible for the food-induced gallbladder contraction. We have consequently measured the plasma concentrations of CCK in the fasting and the stimulated state in pregnant women and in age-matched non-pregnant controls. In a subset of pregnant women and controls the gallbladder volume was measured with ultrasound. The results show that whereas basal CCK concentrations were normal, the response to an oral preparation that contracts the gallbladder was increased in pregnancy. Moreover, the secretion of CCK correlated well with gallbladder emptying. We conclude that the behaviour of the gallbladder in pregnancy is not due to impaired secretion of CCK.