Insulin-like growth factor 1 and its binding protein 1 during normal and diabetic pregnancies.
Investigations of circulating insulin-like growth factor 1, hPL, and infant size during pregnancy in normal and insulin-dependent diabetic women have yielded conflicting results and have not been analyzed longitudinally. We studied serial changes in maternal serum insulin-like growth factor 1 levels (measured by radioimmunoassay after acid ethanol extraction) throughout pregnancy in 22 normal women and in 38 with insulin-dependent diabetes. The diabetic women had significantly lower serum insulin-like growth factor 1 concentrations than normal women throughout pregnancy and after delivery, although the rates of change in both groups of women were similar. Within-patient analysis showed a significant decrease in serum insulin-like growth factor 1 between 6-12 weeks' gestation and a significant increase between 24-32 weeks, followed by a significant decrease from 36 weeks' gestation to 12 weeks after delivery. Incremental changes in insulin-like growth factor 1 between 24-32 weeks' gestation correlated significantly with incremental changes in hPL (r = 0.40; P less than .001) and with birth weight (r = 0.37; P less than .01), but not with ultrasound measurements of fetal growth. The correlation of increments in insulin-like growth factor 1 and birth weight became nonsignificant when the association of hPL with both insulin-like growth factor 1 and birth weight was taken into account. Neither insulin-like growth factor binding protein 1 (placental protein 12) nor its ratio to insulin-like growth factor 1 showed any association with infant size. The physiologic changes in maternal serum insulin-like growth factor 1 in pregnant diabetic women do not appear related to the increased birth weight of their infants.
University Department of Obstetrics and Gynecology, Princess Mary Maternity Hospital, Newcastle upon Tyne, England.
P G
PG
Whittaker
M O
MO
Stewart
A
A
Taylor
R J
RJ
Howell
T
T
Lind
D000328:Adult; D001724:Birth Weight; D002352:Carrier Proteins / Q000097:blood*; D005314:Embryonic and Fetal Development / Q000502:physiology; D005260:Female; D006801:Humans; D018969:Insulin-Like Growth Factor Binding Proteins; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008137:Longitudinal Studies; D009929:Organ Size; D010920:Placenta / Q000033:anatomy & histology; D011247:Pregnancy / Q000097:blood*; D011254:Pregnancy in Diabetics / Q000097:blood*; D012016:Reference Values; D013002:Somatomedins / Q000378:metabolism*; D014463:Ultrasonography
D002352:Carrier Proteins; D018969:Insulin-Like Growth Factor Binding Proteins; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I