Absent or reversed end diastolic flow (AREDF) velocities in the umbilical artery were identified in 25 high risk pregnancies. In six pregnancies the fetus was abnormal and all but one of these ended in perinatal death. Of the 19 morphologicaily normal fetuses, three died in utero and there were four neonatal or infant deaths. The mortality rate was 48% for ali pregnancies and 37% for those with morphologicaily normal fetuses. There was a highly significant increased risk for the development of necrotising enterocolitis in those morphologicaily normal fetuses with AREDF (53%) compared with controls (6%) who did have umbilical artery end diastolic flow velocities in fetal life. There were no significant differences between the matched pairs for parameters of neonatal outcome chosen to reflect neonatal morbidity. These findings demonstrate the close association between AREDF and necrotising enterocolitis that appears to be independent of other variables such as degree of growth retardation, prematurity, and perinatal asphyxia.

Abnormal uteroplacental resistance at 18 weeks' gestation was associated with a significant increase in adverse pregnancy outcome. Low-dose aspirin did not reduce pregnancy complications in women with uteroplacental insufficiency.

Only four cases of fetal gallstones have been reported previously, which implies that this condition is rare. Gallstones in children have been reported more frequently, and it may be that some of these are present in fetal life. Over a 12 month period in this department, seven cases of gallstones or sludge were seen within the fetal gallbladder. The variable appearances of fetal cholelithiasis are described and the possible causes discussed. Fetal gallstones may not be as rare as indicated by the paucity of cases in the literature.

Normal biometric ranges for fetal growth in a captive breeding baboon (Papio hamadryas) colony are described. Measurements include crownrump length, biparietal diameter, binocular distance, head circumference, abdominal circumference, femur length and amniotic fluid index. The pattern of fetal growth is compared with other baboon subspecies and man. The uses and limitations of such data for breeding colony management and optimum utilisation of experimentally derived data are discussed.