[Incidence and causes of fetal and neonatal macrosomy]

Amongst the 7486 babies born at the Department of Gynecology and Obstetrics in Cologne from 1974 to 1978, 536 neonates displayed a birthweight of more than 4000 g. The obstetrically relevant data from 523 deliveries were evaluated retrospectively. We compared and contrasted the results with a reference group of 511 neonates with a normal weight (2500-3999 g) according to the matched pair principle. The incidence of macrosomic neonates amounted to 7.2% of total deliveries in the observation period. On comparing the average age of the mothers, we found a rise from 27.4 years (mothers of the reference group) to 29.4 years in mothers of babies weighing 4000-4499 g and 30.3 years in mothers with babies weighing 4500 g and more. The proportion of the pregnant mothers over 40 years old was 4.6% as compared to 2% in the reference group in macrosomic babies. The parities show a decrease of the primiparae and an increase of the multiparae amongst mothers of macrosomic babies. The rate of primiparae was 49.3% in the group of babies of normal weight as compared to 33.3% in moderately overweight (4000-4499 g) and 23.4% in the highly overweight babies (4500 g and over). The large proportion of adipose mothers in neonatal macrosomy was also striking. The average weight of the women at the end of pregnancy was 71.4 kg in the reference group and rose to 78.6 or 86.8 kg, respectively, in the mothers of macrosomic neonates. In 453 puerperal mothers who had delivered a macrosomic baby, an oral glucose tolerance test (oGTT) was performed in the first 72 hours after delivery. This was pathological in 25.8% of mothers of moderately overweight children, and was pathological in 29.7% of mothers of distinctly overweight babies. This thus confirmed the correlation between diabetogenic metabolic stress and macrosomy. Evaluation of the course of birth revealed a distinctly raised risk of asphyxia with restriction of the vitality index and increase of abnormal internal and neurological features especially for the neonates with a weight of 4500 g and more. Our goal must therefore be to diagnose macrosomy better than so far by foetal biometry in order to counteract the risks described by prospective control of pregnancy and delivery.