Increasing prevalence of macrosomia in Flanders, Belgium: an indicator of population health and a burden for the future

Macrosomia, defined as birth weight > 4 kg, increased in Flanders from 7.3% (4899/67143) in 1991 to 8.63% (6034/69924) in 2010 (p < 0.0001) in singleton pregnancies at term. There are at least 3 important factors contributing to this evolution. (1) Increase of maternal stature and length: during the last century, mean length of Belgian women increased with approximately 10cm to the current value of 1.66 m. (2) Increase of maternal age: the proportion of pregnant women aged 35 years or more increased significantly from 6.1% in 1991 to 14.3% in 2010. (3) Increase of maternal overweight or obesity: between 1994 and 2000, there was an increase of 4% for both overweight and obesity in women and today, 44% of Belgians are overweight (BMI > 25 kg/m²), and 12% are obese (BMI > 30 kg/m²). From these data, rate and increase of macrosomia can be -considered indirect indicators of general public health. Next to the risks for obstetrical complications, neonates > 4 kg are at risk for development of adult obesity and type 2 diabetes with related diseases, such as hypertension and metabolic syndrome. As adults, they also tend to deliver macrosomic baby's themselves. As such, macrosomia at birth is a burden for a community's future health status, health care and related costs. Prenatal health care workers should be aware of the relevance to prevent macrosomia in the first generation by -implementing guidelines on nutrition, physical activity and appropriate weight gain into routine preconceptional and prenatal care, screening for gestational diabetes with strict monitoring of blood sugar levels in affected -individuals, and promotion of breastfeeding.