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

Abstract

Aims/hypothesis. To investigate the incidence of foetal macrosomia (i.e. birth weight >90th percentile) in a nonselected nationwide cohort of women with Type I (insulin-dependent) diabetes mellitus in The Netherlands and to identify risk indicators predictive for macrosomia. Methods. We conducted a prospective nationwide cohort based survey regarding the outcome of Type I diabetic pregnancy in The Netherlands. Data of 289 women who gave birth to a live singleton infant without major congenital malformations at more than or equal to 28 weeks of gestation are shown.Results. The incidence of foetal macrosomia was very high (48.8%), with 26.6% of infants weighing more than 97.7th percentile. Glycaemic control during pregnancy was good (i.e. mean HbA 1c ≤7.0%), in almost all (84%) women. Multiple logistic regression analysis resulted in a predictive model for macrosomia that incorporated five variables: third trimester HbA 1c (Odds Ratio [95% Con- . Third trimester HbA 1c was the most powerful predictor for the occurrence of macrosomia, but its predictive capacity was weak (explained variance <5%). Conclusion/interpretation. Despite apparent good glycaemic control, the incidence of foetal macrosomia in this non-selected prospective nationwide cohort of 289 Type I diabetic women was very high. Third trimester HbA 1c was the most powerful predictor, but its predictive capacity was weak. Thus, future research should focus on new more detailed glucose monitoring techniques (such as a continuous glucose monitoring system) as well as to alternative factors to reduce 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].Foetal growth depends on foetal, placental and maternal factors. Determinants affecting foetal growth are genetic factors, fetal hormones (insulin, insulinPrevention of foetal macrosomia in pregnancies with Type I (insulin-dependent) diabetes mellitus would reduce serious perinatal morbidity and mortality. Mac-

Large‐for‐gestational‐age (LGA) neonate predicts a 2.5‐fold increased odds of neonatal hypoglycaemia in women with type 1 diabetes

“…Our results agree with the literature in that a higher third trimester A 1c was predictive of LGA after adjusting for potential confounders [4,5,26,27]. Even though Evers et al found that third trimester A 1c predicted macrosomia, it was a weak predictor that explained less than 5% of the variance [5].…”

“…Even though Evers et al found that third trimester A 1c predicted macrosomia, it was a weak predictor that explained less than 5% of the variance [5]. A recent study by Law et al was able to demonstrate that significantly higher evening glucoses but significantly lower late afternoon glucoses in the third trimester, as recorded by continuous blood glucose monitoring, were associated with LGA neonates [28].…”

“…There is a growing body of evidence demonstrating that many of these risks can be partially ameliorated by intensive glucose control both prior to conception and throughout pregnancy [3,4]. Neonatal hypoglycaemia and large-for-gestational-age (LGA) neonates are very common complications of pregnancies in women with pre-gestational diabetes with rates varying from 64% to 69% and 49% to 63%, respectively [1,[5][6][7].…”

“…The delivery of a macrosomic or LGA infant is common in pregnancies complicated by type 1 diabetes [5,14].…”

“…[15]. Glycaemic control in pregnancy is classically considered an important determinant in the risk of LGA; however, the high frequency of LGA despite good maternal glycaemic control suggests that this relationship is more complex [5]. Limited data suggest that LGA is a potential risk factor for neonatal hypoglycaemia in women with type 1 diabetes [13].…”