(Severe periconceptional life events and the sex ratio in offspring: follow up study based on five national registers)
Psychological stress associated with severe life events around the time of conception seem to lower the odds of having a male baby, suggest researchers in a paper in this week's BMJ. Dr Dorthe Hansen, from the John F Kennedy Institute and the Danish Epidemiology Science Centre and colleagues from the Centre for Research in Health and Social Statistics and the Danish Epidemiology Science Centre analysed the male to female ratio of 3072 babies who had been conceived amidst traumatic events. They found that the proportion of boys was 49 per cent as opposed to 51.2 per cent in their control group.
Hansen et al conclude that psychological stress related to severe life events may alter the sex ratio of offspring through changes in sexual activity, changes in hormones around the time of conception, reduced semen quality or an increased rate in miscarriage of male babies.
Contact:
Dr Dorthe Hansen, Paediatrician, John F Kennedy Institute, Glostrup, Denmark