Presented at the Neonatal Society 2001 Summer Meeting.
Doherty CB, Hales CN
University of Cambridge, Department of Clinical Biochemistry, Cambridge, UK
Background: Diet in late pregnancy plays an important role in fetal growth. During the Dutch Hunger Winter, exposure to famine in the last trimester of pregnancy had greater effects on birth weight than exposure during the previous two trimesters (1). Famine exposure in late pregnancy also had larger effects on the offspring in middle age in terms of glucose tolerance and weight gain. The mechanistic basis of these programmed effects remains unclear.
Aim: To determine if late pregnancy malnutrition affects a) selective organ growth (suggesting vascular alteration antenatally) and b) appetite in the offspring.
Study Design: Pregnant Wistar rats (n=18) were randomised to receive a) control diet for two trimesters and low protein (8%) diet in the third trimester (late low protein – LLP), b) control diet throughout pregnancy or c) low protein (8%) diet throughout pregnancy (LP). Body and organ weights of the offspring were studied at days 3 and 21 (weaning) postnatally
Results: Results are expressed as mean and standard deviation of the mean.
**P<0.01, *P<0.05 (LLP vs Control). fff P<0.001, ff P<0.01, f P<0.05 (LLP vs LP).
At day 3 postnatally body and kidney weights were significantly lower in the late low protein group (LLP) compared with controls and significantly heavier compared with the LP group. Brain weight was significantly heavier in the LLP group versus the control group. By day 21 postnatally body weights were significantly heavier in the LLP group compared with controls. Absolute brain weight was no longer different. Stomach weight (a proxy for appetite ) was significantly heavier in the LLP group compared with both other groups.
Conclusions:
1. Maternal protein restriction in late pregnancy is associated with selective changes in organ weight suggesting alterations in antenatal blood flow.
2. This antenatal diet pattern may be associated with increased appetite in the offspring.
3. Maternal protein restriction in late pregnancy has less of an effect on birth weight than protein restriction throughout pregnancy in this model.
References
1. Ravelli et al. The Lancet 1998; 351, 173-7