Maternal undernutrition alters fat cell size distribution, but not lipogenic gene expression, in the visceral fat of the late gestation guinea pig fetus

Maternal weight gain across pregnancy in absolute terms (A) and as a percentage of body weight in the preceding week of pregnancy (B) in Control (open circles) and undernutrition (closed circles) dams. Undernutrition dams were lighter than Control dams before and throughout pregnancy (P < 0.05) but exhibited a different pattern of weight gain during the first 2 weeks of pregnancy. Percent body weight gain from the previous week was calculated using the formula percent body weight gain in week b = ((body weight in week a − body weight in week b) body weight in week b) × 100. Multifactorial ANOVA with repeated measures where sex, treatment and time were the independent variables. * Denotes P < 0.05 compared with Control group.

The effect of maternal undernutrition on placental (A–C) and fetal weight (D) in Control (open circles) and UN (closed circles) guinea pigs. Maternal body weight gain across pregnancy (A) was related to mean placental weight (Fig. 2A; r² = 0.32; P = 0.04; y = 0.005x + 3.0). Interestingly, maternal body weight gain in week 2 of pregnancy was exhibited the strongest relationship with placental weight in late gestation when weight gain in the individual weeks of pregnancy was assessed separately (Fig. 2B; r² = 0.59; P = 0.002; y = 0.2x + 4.2). Maternal undernutrition resulted in lower placental (C) and fetal (D) weight compared to Controls.

The effect of maternal undernutrition on fetal weight and relative perirenal fat in Control (A) and UN (B) fetal guinea pigs. There was no significant relationship between fetal weight and relative perirenal fat mass in the Control fetuses (Fig. 1A, P = 0.053). In the UN group, however, there was a significant inverse relationship between fetal weight and relative perirenal fat mass (Fig. 2B, r² = 0.81, P = 0.005, relative PAT = −0.0002 fetal weight + 0.0264).

The percentage of lipid locules within different cell size categories between ad libitum fed and UN fetal guinea pigs at 59–62 d gestation. There was a significant effect of UN on the distribution of lipid locules across different size categories as determined by one-way ANOVA. Asterisks (*) denote a significant difference between the proportion of lipid locules within a particular size category in 59–62 d Control (open bars) and UN (closed bars) fetal guinea pigs (P < 0.05) as determined by a Duncan’s post-hoc.