A new study finds that women who give birth in winter are more likely to suffer from postnatal depression because of a lack of sunlight in their final trimester
According to the study, those who enter their final trimester during ‘shortening’ daylight hours are 29 per cent more likely to suffer from the mental-health condition.
Experts say that sunlight is thought to trigger the production of the hormone serotonin, which boosts a person's mood and helps them feel calm. However, the switch from the long days of summer to short winter days is thought to trigger depression in expectant mothers.
The research, carried out at San Jose University, analysed two studies with a total of 293 women and investigated the amount of daylight the women were exposed to during the last trimester of their pregnancies.
They also completed a questionnaire that assessed how often they experienced depression symptoms within the first three months of parenthood.
Results, published in the Journal of Behavioral Medicine, suggest pregnant women have a 30 per cent risk of developing postnatal depression overall.
The risk falls to just 26 per cent among those who are in their third trimesters during 'long' daylight hours - which the researchers defined as being from May 6 to August 4.
Women who are in their final stage of pregnancy between August and early November - 'short' days - are the most at risk, with a 35 percent chance of suffering from postnatal depression.
The researchers recommend women with a history of depression who are in the final stage of their pregnancies during the short daylight months use light boxes. This involves sitting in front of a light-emitting box for around half-an-hour at the start of each day.
Light therapy is thought to stimulate the sun's rays that are missing during the winter months.
However, postnatal depression occurs when a woman feels persistently sad, tired and withdrawn, as well as her struggling to bond with her baby.
And many men may struggle with the condition as women, research suggests....