The Home Observation of Periconceptional Exposures (HOPE) Study will use a novel and simple method for determining ovulation/conception near the time that it occurs, known as the Peak Day method. Environmental exposures to disinfection by-products (DBP) and bis-phenol-A (BPA) will be measured around the time conception occurs. Scientists have hypothesized that very early exposures to environmental chemicals may have both short-term and long-term health effects on growth and development. Previous studies have been limited by a couple’s inability to recall exposure to chemicals at the time of conception and during pregnancy. By identifying the date that pregnancy started, scientists can help determine when testing should occur during pregnancy in order to match important developmental milestones. Methods exist to determine the most fertile day using lab tests, but they are expensive and not practical for long-term use.
1. Conduct prospective, peri-ovulational biomonitoring for disinfection by-products (DBP) and bis-phenol-A (BPA) in a human preconception cohort using a novel strategy of self-collection of environmental and biological specimens triggered by observation of fertility signs in a community-dwelling population.
2. Evaluate the association between prospectively measured exposures in the male and the female and the reproductive outcomes of semen quality and time to pregnancy.
3. Quantify the degree of misclassification bias generated by retrospective exposure assessment methods in common use (participant self-report of past exposure using a recall questionnaire and/or archival environmental monitoring data) compared to prospective peri-ovulational biomonitoring and sampling.