Men whose mothers have been very stressed in the first 18 months of gestation are less fertile. The discovery comes from the Western Australia's Raine Study, a multigenerational study conducted on men between 20 and 30 years old.
According to the researchers, the male reproductive organs are particularly vulnerable in the first weeks of gestation. To prove it, between 1989 and 1991 they recruited nearly 3,000 women at the 18th week of gestation. During these years, they submitted questionnaires to them about any stressful events that occurred just before conception and in its early stages. The questions included death, divorce, marital problems, loss of work, financial problems.
The participants gave birth to 2868 children, of which 1454 boys. Of these, 643 have continued to participate in the study to date. The researchers examined their reproductive functions with testicular ultrasound examinations and sperm analysis. In a second step, they crossed the data collected with the answers given by mothers during gestation, looking for possible links between fertility and maternal psychological conditions. 63% of men had been exposed to at least one traumatic event in prenatal age, at the earliest stages of gestation.
The tests showed that they have less sperm and less motility. To make the results more precise, the researchers also took into account other factors that could affect reproductive health, not related to maternal health. Even excluding other variables, men exposed to very stressful events in the early stages of life have 36% less sperm. Furthermore, motility is 12% lower and testosterone levels are reduced by 11%. There is therefore the possibility that maternal psychological health can really damage or improve the future fertility of children.