Chapter 40: Infant of a Diabetic Mother

I. Intensive care

Perinatal morbidities from maternal diabetes

1. Definition

   Diabetes during pregnancy may have an adverse impact on the embryo and fetus and increase the rate of perinatal and long-term complications.

   1. Type 1 diabetes is classified as a requirement for insulin supplementation to prevent ketoacidosis, or Type 2 diabetes is when hyperglycemia is caused by insulin resistance and is controlled by diet or oral hypoglycemics.

   2. Diabetic mothers may suffer from pregestational diabetes (PGD) or develop glucose intolerance during pregnancy (gestational diabetes or GD) when carbohydrate intolerance is first diagnosed during pregnancy. GD is diagnosed according to biochemical parameters established to detect women whose offspring are at increased risk of adverse pregnancy outcome due to high glucose blood levels.

   3. Since the associations between maternal glycemia and adverse outcomes are continuous across the range of glucose concentrations, the criteria were set in purpose to identify the infants at risk for birthweight above the 90th percentile. Criteria used by most centers suggest that all pregnant women should be screened and diagnosed by a 50-g glucose challenge test and those testing positive have a 3-hour 100-g oral glucose tolerance test (GTT) at 24 to 28 gestational weeks.

   4. Criteria

      1. 50-g glucose challenge test: Two cutoffs levels are suggested:

         (1) plasma glucose after 1 hour above 7.2 mmol/L (130 mg%)

         (2) plasma glucose level above 7.8 mmol/L (140 mg%)

      2. GTT: Normal values—0 min <5.3 mmol/L (95 mg%); 60 min <10 mmol/L (180 mg%); 120 min <8.6 mmol/L (155 mg%); 180 min <7.8 mmol/L (140 mg%). The American Congress of Obstetricians and Gynecologists (ACOG) in 2001 recommended the 50 g with a cutoff level of 7.2 mmol/L (130 mg%) and allows the GTT with two cutoffs: lower and higher.

      3. Due to the increased rate of infants large for gestational age (LGA) with adverse outcome, more recent recommendations increased the number of women diagnosed as suffering from GD. According to the criteria set by the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) group in 2008, based on the International Association of the Diabetes and Pregnancy Study Groups all pregnant women without previous diagnosis of diabetes should be screened at 24 to 28 weeks by 75 g oral glucose challenge test. Levels exceeding 5.1 mmol/L (92 mg%) of fasting blood glucose, 10 mmol/L (180 mg%) 1 hour post-glucose load and 8.5 mmol/L (153 mg%) 2 hours post-glucose load are indicative for overt GD.

      4. The ACOG recommends universal screening excluding women with all the specified criteria: under 25 years, no racial risk factors, BMI <25, no history of glucose intolerance, no history of adverse pregnancy outcome that may have been a result of glucose intolerance and no history of diabetes in first degree relatives.

2. Incidence/prevalence

   1. In a meta-analysis of the literature, the prevalence of GD was found to be 1.7% to 11.6%.

   2. The frequency of diabetes mellitus during pregnancy differs between countries. When using the new criteria established by the HAPO, it reaches 17.8% among their cohort with a median ...