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Amniotic fluid insulin levels identify the fetus at risk of neonatal hypoglycaemia
Author(s) -
Fraser R. B.,
Bruce C.
Publication year - 1999
Publication title -
diabetic medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.474
H-Index - 145
eISSN - 1464-5491
pISSN - 0742-3071
DOI - 10.1046/j.1464-5491.1999.00104.x
Subject(s) - medicine , fetal macrosomia , gestational diabetes , obstetrics , fetus , gestational age , birth weight , insulin , gestation , diabetes mellitus , pregnancy , amniotic fluid , caesarean section , endocrinology , biology , genetics
Summary Aims To investigate the use of amniotic fluid insulin (AFI) as a predictor of neonatal morbidity in the macrosomic newborn of the diabetic mother, in view of the fact that raised AFI levels are a marker for fetal hyperinsulinaemia. Methods AFI was measured by radioimmunoassay in a group of pregnant diabetic women ( n = 63) with normal ( n = 41) or accelerated fetal growth ( n = 22). Results Using log transformed data, liquor insulin was found to be significantly higher in pregnant women with Type 1 and Type 2 diabetes mellitus (17.6 mU/l; 95% confidence interval (CI) 11.7–26.4) compared with women with gestational diabetes mellitus (GDM) (8.2 mU/l; 95% CI 4.8–13.8, P = 0.02) or impaired glucose tolerance (IGT) (6.2 mU/l; 95% CI 4.9–8.0, P = 0.0001). In the group with macrosomic fetuses (birth weight > 90th centile for gestational age), there was a significantly higher incidence of elective Caesarean section (CS) and emergency CS (12/22) compared to those with appropriate for gestational age (AGA) fetal weights (birth weight > 10th and < 90th centiles for gestational age) (9/41, P = 0.009). There was no significant correlation between raised AFI and macrosomia except in the Type 1 diabetic women, in whom the AGA group mean was 13.2 mU/l (95% CI 7.4–23.3), and 34.6 mU/l (95% CI 17.5–68.4 P = 0.022) in macrosomia. In the latter group, hypoglycaemia requiring treatment was significantly more common in the macrosomic hyperinsulinaemic neonates (8/13), compared to normoinsulinaemic neonates in the same group (0/9, P = 0.005). Conclusions Identification of the hyperinsulinaemic fetus before delivery might allow the intensification of maternal insulin therapy leading to a reduction in incidence and severity of diabetic fetopathy. Pregnancy with a normoinsulinaemic fetus could be allowed to continue to the onset of spontaneous labour, which might result in a lower CS rate.