MATERNAL HYPERGLYCEMIA IS NOT THE ONLY CAUSE OF MACROSOMIA - LESSONS LEARNED FROM THE NONOBESE DIABETIC MOUSE

Maternal hyperglycemia has been implicated as the major cause of neona tal macrosomia, yet clinicians frequently report the birth of large-fo r-gestational-age infants in normoglycemic pregnancies. We examined th e relationship between birthweight, maternal blood glucose (BG), glyco sylated hemoglobin (GHb) levels, litter size, maternal age, gestationa l du ration, and parity using the non-obese diabetic (NOD) mouse model . We observed 133 litters and analyzed the birthweight in relation to BG, GHb, litter size maternal age, gestational duration, and parity. W e found that mean litter birthweight was significantly negatively corr elated with the total number of pups in each litter (r = -0.39; P<0.01 ) and significantly positively correlated with parity (r = 0.19; P<0.0 5) and maternal age (r = 0.22; P<0.05). The total number of pups was s ignificantly negatively correlated with parity (r = -0.33; P<0.01) and with parent age (r = -0.21; P<0.05). The relationship between birthwe ight and GHb was bimodal. No relationship was found with a GHb less th an 2.5%, a significant positive correlation was found for GHb between 2.6% and 4.0% (r = 0.67; P<0.01), and a negative relationship was foun d when GHb was above 4.0%. Thus, increased parity, maternal age and gl ucose are associated with increased birthweight. Mild hyperglycemia pl ays the major role when age, maternal size, gestational duration, and parity are controlled.