Lipid and Lipoprotein Concentrations in Pregnancies Complicated by Intrauterine Growth Restriction

Abstract

Previous studies have shown that in preeclampsia, plasma lipids climb substantially above levels seen in normal pregnancies. Such lipid changes may play a role in the endothelial damage characteristic of preeclampsia. Pregnancies complicated by intrauterine growth restriction (IUGR), without preeclampsia, have similar placental pathology to preeclampsia despite the absence of the maternal systemic manifestations of hypertension and proteinuria. The aim of this study was to perform a cross-sectional study of lipid and lipoprotein concentrations in the third trimester, from normal pregnancies, and those complicated by IUGR without preeclampsia. Our hypothesis was that, in contrast to the exaggerated lipid changes seen in preeclampsia, lipid and lipoprotein concentrations in IUGR would be similar to those of matched healthy pregnant controls. Fasting blood samples for lipids and lipoprotein fractions were taken in the third trimester, from eight women with IUGR; and eight women with uncomplicated pregnancies, matched as a group for age, booking weight, parity, and gestational age at sampling. There were no significant differences (P > 0.05) in the median concentrations of triglyceride, high-density lipoprotein, and very-low-density lipoprotein 1 (VLDL1), between cases and controls. However, women with IUGR pregnancies had significantly lower cholesterol [4.95 mmol/L (3.35-7.10) vs. 7.47 (5.75-8.45); median (range) for IUGR patients and controls, respectively; P < 0.01], low-density lipoprotein (LDL)-cholesterol [2.45 mmol/L (0.95-3.60) vs. 4.25 (3.35-5.60); P < 0.01], VLDL2 mass [59.0 mg/dL (37-87) vs. 103.0 (64-168); P < 0.01], intermediate-density lipoprotein mass [56.0 mg/dL (31-110) vs. 125.6 (91-157); P < 0.01], and total LDL mass [221.0 mg/dL (104-237) vs. 380.3 (267-534); P < 0.01]. In addition, it was noteworthy that, with respect to LDL-cholesterol and total LDL mass, there was little or no overlap in the ranges of concentrations measured between cases and controls. Because VLDL2 and intermediate-density lipoprotein are the synthetic precursors to LDL in the circulation, their significantly lower median concentrations imply a failure of appropriate LDL synthesis in IUGR pregnancies. Whatever the mechanism, if our results are confirmed in larger studies and longitudinal investigations, then LDL-cholesterol measurements (when LDL-cholesterol fails to rise appropriately or is low in the third trimester) may be of use in identifying mothers with, or at risk of, a pregnancy complicated by IUGR.

Effect of Acipimox on Plasma Lipids and Glucose/Insulin in Pregnant Rats

“…Therefore, the reduction in fetal weight observed on acipimox treatment during the last 3 days of pregnancy could be expected as plasma levels of both FFA and TG decreased. These data are in agreement with the findings in human pregnancies where a positive correlation between the maternal levels of plasma TG and the newborn weight has been observed [10], and the lower weight observed in newborn from pregnancies with a smaller increase in plasma cholesterol through pregnancy [11]. Overall, these results indicate that the elevation of maternal lipid levels through pregnancy is important to allow the maximal fetal growth.…”

“…Therefore, decreasing the hypertriglyceridemia of late pregnancy may be of therapeutic use. Nevertheless, this therapeutic approach may not be risk free for the fetus, because in human pregnancies maternal TG have a positive correlation with the newborn weight [10], and decreased lipid levels have been associated with intrauterine growth retardation [11]. To test how a decline in FFA and TG during late pregnancy affects maternal glucose/insulin relations, we studied the effects of acipimox, a powerful inhibitor of lipolysis [12][13][14] in late pregnant rats, when adipose tissue lipolytic activity is enhanced.…”

Ethnic differences in maternal total cholesterol and triglyceride levels during pregnancy: the contribution of demographics, behavioural factors and clinical characteristics

“…It is thought that progressive increase in oestrogen levels during gestation induces most of these alterations in lipoprotein metabolism (Desoye et al, 1987), which suggests the necessity of these metabolic changes for pregnancy maintenance and foetal growth. Indeed, reduced maternal TC levels are associated with intrauterine growth restriction and preterm delivery (Sattar et al, 1999;Edison et al, 2007). Conversely, marked elevated maternal TC and TG levels are associated with an increased risk on pre-eclampsia and other pregnancy-related complications (vandenElzen et al, 1996;Enquobahrie et al, 2004).…”

Lipid Profile of Healthy Women During Normal Pregnancy

“…There is evidence that triglyceride concentration, if measured bet ween 9 and 12 weeks of gestation, has moderate predictive value for subsequent glucose tolerance in pregnancy. For that reason further studies are needed to investigate the role of early measurement in the screening and management of cardiovascular damage (8,10).…”

“…In case drugs are necessary, then the statins will be the drugs of choice in hypercholesterolemia along with fibrates for com bined hypercholesterolemia and hypertriglycer i de mia. There are limited data to sug gest that these drugs are not major human teratogens, however it is not recom mended to use them during pregnancy (10).…”