Maternal hormones linking maternal body mass index and dietary intake to birth weight.
BACKGROUND
Obese women often give birth to large-for-gestational age infants (typically defined as a birth weight greater than the 90th percentile), who are at risk of birth injuries and of developing metabolic syndrome later in life. The mechanisms underlying increased fetal growth remain to be established.


OBJECTIVE
We aimed to identify maternal hormones that can explain the link between dietary intake, body mass index (BMI), and birth weight.


METHODS
Pregnant women with BMIs (in kg/m(2)) ranging from 17 to 44 (n = 49) were recruited in gestational weeks 8-12. Serum hormone concentrations were measured and dietary history interviews were performed in the first and third trimesters. Multiple regression models were produced to identify hormones that correlate with birth weight and are influenced by BMI or dietary factors.


RESULTS
We found a strong positive correlation between BMI and first- and third-trimester insulin and leptin concentrations and a negative correlation between BMI and first-trimester adiponectin and first- and third-trimester insulin-like growth factor binding protein-1 (IGFBP-1). Maternal total fat intake in the first trimester was positively correlated with maternal leptin and inversely correlated with adiponectin. In addition, third-trimester total fat intake was positively correlated with circulating resistin concentrations. First-trimester maternal serum resistin was positively correlated with birth weight, whereas third-trimester maternal IGFBP-1 was negatively correlated with birth weight.


CONCLUSIONS
High first-trimester maternal serum resistin and low third-trimester IGFBP-1 were correlated with increased birth weight. We propose that low serum concentrations of IGFBP-1 represent a link between high BMI and increased fetal growth by increasing the bioavailability of insulin-like growth factor-I, which up-regulates placental nutrient transport.
Perinatal Center, Institute of Neuroscience and Physiology, Sahlgrenska Academy at University of Gothenburg, Göteborg, Sweden. nina.jansson@fysiologi.gu.se
Nina
N
Jansson
Anna
A
Nilsfelt
Martin
M
Gellerstedt
Margareta
M
Wennergren
Lena
L
Rossander-Hulthén
Theresa L
TL
Powell
Thomas
T
Jansson
D052242:Adiponectin / Q000097:blood*; D000293:Adolescent; D000328:Adult; D001724:Birth Weight; D015992:Body Mass Index; D004032:Diet; D004041:Dietary Fats; D002149:Energy Intake; D005260:Female; D020567:Fetal Weight; D006728:Hormones / Q000097:blood*; D006801:Humans; D007231:Infant, Newborn; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000097:blood*; D007407:Interviews as Topic; D010920:Placenta / Q000033:anatomy & histology; D011247:Pregnancy / Q000502:physiology*; D011261:Pregnancy Trimester, First; D011263:Pregnancy Trimester, Third
D052242:Adiponectin; D004041:Dietary Fats; D006728:Hormones; D018970:Insulin-Like Growth Factor Binding Protein 1