A team of researchers led by Professor Claude de Tychey, from Universite Nancy 2, France, found that just under a third of the 181 women they studied four to eight weeks after delivery had PND.
Nine per cent of the women in the study ??“ carried out in a French community where they didn't face cultural pressures over the sex of their baby - had severe PND and just over three-quarters of those had given birth to boys.
The team also discovered that, even if women didn't have postnatal depression, giving birth to a boy was significantly more likely to reduce their quality of life than delivering a girl.
???Post-natal depression is very common and poses a major public health problem, especially if it is not diagnosed and treated??? stresses Professor de Tychey.
???When we launched our research, our main aim was to study the effect that gender has on PND. But the overwhelming finding of the study was the fact that gender appears to play a significant role in reduced quality of life as well as an increased chance of severe PND.???
The researchers measured the women's quality of life using a validated questionnaire containing 36 questions. This asked the women to score eight dimensions of their health ??“ physical functioning, physical role, bodily pain, mental health, emotional role, social functioning, vitality and general health - using a 100-point scale.
The results were then collated into male and female births and whether the woman had no, mild or severe PND. Scores were also calculated for their overall physical and mental health. This provided 60 separate quality of life scores.
When the researchers looked at overall results they discovered that:
Women who had given birth to a boy reported lower quality of life scores in 70 per cent of cases compared with women who had delivered a girl, regardless of whether they suffered from PND. When the 10 quality of life scores were added together in each category, women who had no PND had the highest quality of life scores - 713 points for women who had given birth to girls and 648 for women who had delivered boys. When the researchers looked at women with PND, they found higher quality of life scores for women who had delivered girls ??“ 567 if the PND was mild and 541 if it was severe. Women who had delivered boys scored lower totals of 539 if the PND was mild and 498 if it was severe.
The figures also enabled the researchers to compare the gender differences for women with no, mild and severe PND. This showed that:Gender differences were greatest in women who had no PND. If they had given birth to a boy they had lower quality of life scores in 90 per cent of categories than those who had delivered girls. Women with PND also reported lower quality of life scores if they had had a boy ??“ these were lower in 50 per cent of categories if the PND was mild and in 70 per cent of categories if the PND was severe.
???These figures show very clearly that having a boy resulted in lower quality of life scores in all cases??? says Professor de Tychey.
???We also discovered that being a first-time mother had no effect on quality of life scores. Women had the same general scores regardless of whether the recent birth was their first or second baby.???
Just over half of the women who took part (52 per cent) had given birth to boys. 61 per cent of the babies included in the study were first babies (55 boys and 56 girls) and the remainder were second babies.
Women having their second baby were slightly more likely to have had a girl the first time around (59 per cent). The women's ages ranged from 19 to 40 and averaged 29.
???Post-natal depression can have a considerable impact on women as it can affect both their physical and mental health??? stresses Professor de Tychey.
???Previous studies have shown that women who live in cultures where greater value is placed on sons are more likely to suffer from PND if they give birth to a girl.
???However, we believe that this study ??“ carried out in a French community where women didn't face cultural pressures over the sex of their baby ??“ is the first to show that women who give birth to boys are more likely to suffer from severe PND and reduced quality of life. Further research is needed to find out why this happens.
???We believe that our findings have important public health consequences, as they point to the need for developing prevention and early psychotherapeutic programmes for women giving birth to boys.???