Macrosomia in Pregnancy Complicated by Insulin-Dependent Diabetes Mellitus

Abstract

We assessed the factors influencing the birth weight of infants born to 83 women with insulin-dependent diabetes mellitus (IDDM) over a 5-yr period. Maternal glycosylated hemoglobin (HbA1) concentrations at delivery correlated with the percentile birth-weight ratios (r = .43, P less than .001) and indicated that approximately 18% of variance in the birth weight could be ascribed to glycemic control in the third trimester. Fetal macrosomia occurred in 22 (27%) pregnancies. When 20 of these pregnancies were compared closely with 20 nonmacrosomic pregnancies in diabetic women, the mothers of macrosomic infants were found to be more obese, have a history of previous macrosomic birth, and have higher concentrations of serum human placental lactogen and urinary estriols in the third trimester. Macrosomic pregnancy was further distinguished by accelerated fetal growth (judged by serial ultrasonography) from the 32nd wk of gestation and by biochemical (but asymptomatic) hypoglycemia in the neonate. In our study, no serious neonatal morbidity could be attributed to macrosomic pregnancy. Good glycemic control was attained in both groups, and no significant differences between the groups in overall glycemic control throughout pregnancy were noted. Thus, despite good glycemic control, macrosomia remains comparatively common in modern pregnancy complicated by IDDM, and factors other than maternal hyperglycemia must contribute to its etiology.

Macrosomia despite good glycaemic control in Type I diabetic pregnancy; results of a nationwide study in The Netherlands

“…Third trimester HbA 1c was an independent risk indicator for macrosomia, which is in agreement with other studies [4,5]. A third trimester HbA 1c greater than 6.5% was associated with a twofold to threefold increase in macrosomia.…”

“…[Diabetologia (2002) rosomia is related to an increased risk for "unexplained" death in utero and shoulder dystocia during labour, the latter being related to asphyxia, clavicle fracture and/or Erbs palsy [1,2,3]. During the neonatal period macrosomic infants are at increased risk for hypoglycaemia, infant respiratory distress syndrome (IRDS), hyperbilirubinaemia and hypertrophic cardiomyopathy [4,5,6]. A number of long-term population studies have shown that macrosomic newborns of women with diabetes have a higher risk to develop obesity and Type II (non-insulin-dependent) diabetes mellitus at a young age [7,8,9].…”

“…Hyperglycaemia is considered a determinant of excessive foetal growth, although the relationship between glycaemic control during pregnancy and the occurrence of macrosomia is lower than might be expected. Differences in HbA 1c explained only 6 to 23% of the variance in birth weight [5,11,12], whereas 1 h postprandial blood glucose values predicted 28.5% of the macrosomic infants born to diabetic mothers [13]. This relatively weak relationship could be due to the use of inadequate markers of (overall) glycaemic control or due to other yet unknown factors.…”

“…However, despite improved glycaemic control over the past decade, the incidence of macrosomia is still very high (27-43%) and does not seem to decline [1,4,5,14,15,16,17]. When trying to reduce macrosomia in Type I diabetic pregnancies, it would be useful to know the characteristics of women with the highest risk for having a macrosomic infant.…”

Increased Fat Mass and Cardiac Septal Hypertrophy in Newborn Infants of Mothers with Well-Controlled Diabetes during Pregnancy

“…In accordance with the concept of maternal hyperglycaemia-fetal hyperinsulinism, one would also anticipate a parallel reduction in the incidence of macrosomia. This has not been the case; instead, the incidence of fetal macrosomia is unexpectedly high and the rate is increasing [3][4][5][6][7][8][9][10][11] . Thus, despite intensive treatment aiming at near-normoglycaemia, rates of macrosomia 6-10 times higher than normal have been recorded.…”