New research suggests women who are born in the summer are more likely to become healthy adults.
A recent study involving over half a million people revealed how more sunlight and higher levels of vitamin D exposure could be beneficial in the third trimester of pregnancy, Elsevier reported. The research demonstrated how a girl's month of birth could influence both birth weight and when she starts puberty, both of which have significant health impacts later in life. Children who were born in the summer proved to have slightly heavier birth weights on average as well as later puberty onset 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 John Perry, lead author of the study.
To make their findings, the researchers compared the growth and development of 450,000 men and women from the UK Biobank study. The data showed babies born in June, July, and August were generally heavier at birth and taller in adulthood. The study was the first to show that girls born in the summer tended to have a later onset of puberty.
"This is the first time puberty timing has been robustly linked to seasonality," Perry said. "We were surprised, and pleased, to see how similar the patterns were on birth weight and puberty timing. Our results show that birth month has a measurable effect on development and health, but more work is needed to understand the mechanisms behind this effect."
While further research is required to determine the causation of this phenomenon, the researchers believe it is linked to the amount of vitamin D expecting mothers acquire from sunlight.
"We don't know the mechanisms that cause these season of birth patterns on birth weight, height, and puberty timing," Perry said. "We need to understand these mechanisms before our findings can be translated into health benefits. We think that vitamin D exposure is important and our findings will hopefully encourage other research on the long-term effects of early life vitamin D on puberty timing and health."
The findings were published in a recent edition of the journal Heliyon.
