Analysis of carbohydrate-intolerant profiles of mothers with normal glucose tolerance tests and their large for gestational age neonates.
OBJECTIVE
To examine endocrine states of mothers with normal 75-g oral glucose tolerance tests (GTTs) who gave birth to large for gestational age (LGA) neonates (group I) and to examine those neonates.


METHODS
We examined plasma glucose levels and serum immunoreactive insulin responses after the 75-g oral GTT was given to group I mothers (N = 34), mothers with an abnormal oral GTT who gave birth to LGA neonates (group II, N = 21), and those with normal oral GTTs having appropriate for gestational age neonates (group III, N = 173). We also examined the infants, checking neonatal birth weight, levels of immunoreactive insulin and C-peptide immunoreactivity in cord sera at birth and the lowest blood sugar level after birth to see if a correlation existed between them.


RESULTS
Group I and II mothers showed higher titers in plasma glucose levels and remarkably enhanced ratios of 60- to 30-minute immunoreactive insulin values (immunoreactive insulin up-ratio) after load compared with those of group III mothers. Cord serum immunoreactive insulin and C-peptide immunoreactivity were significantly higher and the lowest blood sugar level was significantly reduced in group I and II neonates compared with those in group III. We observed a positive correlation between cord serum immunoreactive insulin, C-peptide immunoreactivity, and birth weight, but a negative correlation between cord serum immunoreactive insulin, birth weight, and the lowest blood sugar level in group I and II neonates (strongest tendency in group II), but not in group III neonates.


CONCLUSIONS
All of the abnormal carbohydrate metabolic responses in group I mothers and neonates may result in the promotion of growth in LGA fetuses similar to group II, but to a lesser extent. Identification of group I mothers by the immunoreactive insulin up-ratio after oral GTT will help predict the occurrence of LGA neonates and their possible hypoglycemia.
Fukui
R
R
Department of Obstetrics, Osaka Medical Center, Japan.
Matsuzaki
N
N
Fujita
T
T
Kidoguchi
K
K
Suehara
N
N
Aono
T
T
D001724:Birth Weight; D001786:Blood Glucose / Q000032:analysis; D002096:C-Peptide / Q000097:blood; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D018149:Glucose Intolerance / Q000150:complications; D005951:Glucose Tolerance Test; D006801:Humans; D007231:Infant, Newborn; D007328:Insulin / Q000097:blood / Q000276:immunology; D011247:Pregnancy; D011248:Pregnancy Complications
D001786:Blood Glucose; D002096:C-Peptide; D007328:Insulin