Paternal age affects birth outcomes

The babies of teenage fathers are at higher risk for problems such as premature birth, low birth weight and neonatal death. Previous research had found that babies of teenage mothers were at a heightened risk for premature birth, low birth weight and neonatal death, regardless of the age of the father. And most previous studies on the effect of paternal age have focused on the association of advanced paternal age with congenital anomalies such as babies whose fathers were over the age of 50 years were at higher risk for problems such as heart defects and Down syndrome. To determine whether or not the young age of fathers is associated with the risk of adverse birth outcomes independent of maternal age, researchers in America looked at records relating to 2.6 million babies born in the United States between 1995 and 2000 focussing on the fathers by looking at children whose mothers were aged between 20 and 29 years, but whose fathers were of varying ages, ranging from teenagers to men over 50 years. The babies of fathers aged 19 years and under were more likely to experience problems at birth. Compared to babies of fathers aged between 20 and 29 years—the group with the best record for healthy offspring—those with teenage fathers were 15 per cent more likely to be born prematurely and 13 per cent more likely to have a low birth weight. In addition, babies with teenage fathers had a 22 per cent higher risk to die in the first four weeks after birth, a 41 per cent increased risk to die in the period from four weeks to a year after birth and a 13 per cent higher risk to have a low Apgar score assessing physical condition after delivery. The findings did not detect any elevated risk for premature birth, neonatal death or other adverse outcomes for babies whose fathers were in their 40s or older. However, the results did not specify why babies of teenage fathers were at a higher risk. Social factors were a more likely explanation than possible biological reasons such as differences in the sperm of teenagers compared to older men. Teenage fathers are more likely to come from poor families and have less education, and less likely to use prenatal health services. Another factor associated with teenage fathers could be harming a mother's health during pregnancy by domestic violence, smoking and substance abuse.