Study shows summer babies may be healthier adults

A study from the Medical Research Council (MRC) Epidemiology Unit, University of Cambridge, has found that babies born in the summer months may turn out to be healthier adults.

The researchers behind the UK study looked at whether birth month had an effect on factors such as birth weight, the onset of puberty, and adult height. The study compared the growth and development of around 450,000 men and women.

The results showed that children who were born in the summer – June, July, and August- were slightly heavier at birth, taller as adults, and went through puberty slightly later than those born in winter months.

“When you were conceived and born occurs largely ‘at random’ – it’s not affected by social class, your parents’ ages, or their health – so looking for patterns with birth month is a powerful study design to identify influences of the environment before birth,” said Dr. John Perry, lead author of the study.

Why summer?

Researchers aren’t entirely sure why summer is the better season for healthy birth. Perry and his team think it might have something to do with sunlight and vitamin D production.

“You’ll notice these optimum months coincide with when we have the most sunlight in the UK,” Perry said. When women are exposed to more sunlight in the second trimester of pregnancy they get a higher dose of vitamin D. A vitamin D deficiency has been associated with bone problems for children and for other health concerns, such as rickets. The study does not directly measure the maternal/fetal vitamin D status, so the researchers would like to do further research on the topic, but it is an “interesting result,” Perry said, and an “interesting idea.”

What about my fall, winter, or spring baby? How can they get vitamin D?

Keep in mind, Perry said, your birth month is one of many factors that affect your health later in life. “There are hundreds of factors that determine your future health and there are millions of things that influence birth weight [and] height. This is one incremental factor of many that contribute to this,” Perry said. “Keep in mind it is complicated, but it is an interesting piece of the jigsaw puzzle of biology.”

For all the fall, winter, and spring babies (as well as summer babies kept out of sunlight), don’t forget to talk to your doctor about Baby Ddrops, and your need for vitamin D during pregnancy.

The 2015 study was originally published in Heliyon.