British couples are taking less time to conceive than they were in the 1960s, according to a new study published in The Lancet last week. Dr Michael Joffe, based at the Department of Epidemiology and Public Health, Imperial College London, interviewed 894 women and 6464 men aged 16 to 59. He found that overall, the average time it takes couples to conceive has been falling steadily since 1961.
Dr Joffe found that in 1961-1965, 65 per cent of the people in the study conceived within six months, a figure that rose to 80 per cent over the period 1991-1993. After a year of trying for a baby, 90 per cent of the 1991-1993 group achieved a pregnancy, compared to 79 per cent of the 1961-1965 sample. Dr Joffe writes that the findings cannot be explained by either age at first birth, increased use of fertility treatment or changes in oral contraceptive use.
Dr Joffe says that if male fertility has declined, it has been more than compensated for by an increase in couple fertility. In a report in the Independent newspaper, he suggests that one explanation for the trend might be people timing their efforts better to coincide with a woman's most fertile period.
In a letter to The Lancet commenting on the study, a group of Dutch doctors said that 'the near-panic sometimes expressed in the lay press about the effects of the environmental pollution on sperm quality and male fertility is not justified'.
Sources and References
Time trends in biological fertility in Britain
Fertility rises despite falling sperm counts