The primary objective of this analysis was to describe demographic, physical, lifestyle, and psychosocial factors related to becoming pregnant in six months or less among women under 35 years of age who delivered a live-born infant. We also wished to determine the relative impact of these factors on time to pregnancy, regardless of use of fertility treatment.
Between July 2002 and September 2003, we conducted a survey by telephone interview of 1044 randomly selected women who had recently delivered their first live-born infant in Calgary or Edmonton, Alberta.
Among 575 women who were less than 35 years of age when they began trying to conceive and who ultimately delivered a live-born infant, the most significant predictors of taking more than six months to conceive included being overweight or obese (hazard ratio [HR] 1.34; 95% CI 1.05 to 1.72), having a history of pregnancy complications (HR 1.42; 95% CI 1.02 to 1.99), and having fair or poor self-rated emotional health six months prior to pregnancy (HR 2.02; 95% CI 1.27 to 3.22). The influence of BMI and emotional health on time to conception did not change substantially when women who had assistance with conception (16% of the sample) were excluded from the analysis.
Among those who ultimately carry a pregnancy to delivery, the relationship between high BMI or poor emotional health and delays in conception was evident among women who conceived with or without assistance. Public health strategies that help women to achieve optimal body weight and address issues of emotional health may reduce the need for assisted reproduction.