Researchers from the University of Cambridge have discovered that the season a woman was born in could influence their health later in life.
They believe that more sunlight and therefore higher vitamin D exposure in the second trimester of pregnancy could explain the effect.
The researchers who collected and analyzed data from around 450,000 men and women were seeking to shed more light on the development of diseases.
They found that babies born in June, July, and August were heavier at birth and taller as adults. The study also showed that girls born in the summer started puberty later, an indication of better health in adult life.
Dr. John Perry, lead author of the study said “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.
“This is the first time puberty timing has been robustly linked to seasonality. 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.”