Changes in basal metabolic rate during pregnancy in relation to changes in body weight and composition, cardiac output, insulin-like growth factor I, and thyroid hormones and in relation to fetal growth
2005 (English)In: American Journal of Clinical Nutrition, ISSN 0002-9165, E-ISSN 1938-3207, Vol. 81, no 3, 678-685 p.Article in journal (Refereed) Published
Background: The total energy cost of pregnancy is largely due to an elevated basal metabolic rate (BMR). Large variations in the BMR response to pregnancy have been reported, but the factors associated with this variability are incompletely known.
Objective: The objective was to identify factors associated with variability in the BMR response to pregnancy.
Design: In 22 healthy women, BMR, body weight (BW), total body fat (TBF), fat-free mass (FFM), circulatory variables, serum concentrations of insulin-like growth factor I (IGF-I), and thyroid hormones were measured before pregnancy and in gestational weeks 14 and 32. BMR and BW were also measured in gestational weeks 8, 20, and 35. Fetal weight was estimated in gestational week 31.
Results: In gestational week 14, the increase in BMR correlated significantly with the corresponding increase in BW and with the prepregnancy percentage of TBF. Together these variables explained ≈40% of the variability in the BMR response. In gestational week 32, the increase in BMR correlated significantly with the corresponding changes in BW, TBF, FFM, IGF-I, cardiac output, and free triiodothyronine. The increase in BW in combination with fetal weight or with the elevated concentration of IGF-I in serum explained ≈60% of the variability in the increase in BMR.
Conclusions: Weight gain and the prepregnancy percentage of TBF—ie, factors related to the maternal nutritional situation—are important factors with regard to the variability in the BMR response to pregnancy. Thus, it is important to consider the nutritional situation before and during gestation when assessing pregnancy energy requirements.
Place, publisher, year, edition, pages
2005. Vol. 81, no 3, 678-685 p.
Basal metabolic rate, cardiac output, body composition, free triiodothyronine, insulin-like growth factor I, pregnancy
National CategoryMedical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-24769Local ID: 7030OAI: oai:DiVA.org:liu-24769DiVA: diva2:245092