Compliance with daily, home-based collection of urinary biospecimens in a prospective, preconception cohort

BACKGROUND: Exposures in the periconceptional environment may impact fertility and future health. Assessing time-varying exposures during the periconceptional window requires identifying approximate fertile windows around ovulation. In this prospective cohort study, we instructed women in daily cervical fluid observation and interpretation to identify incipient ovulation; they used this information to time daily urine collection for both partners. Timing and completeness of collection were compared to expert review. METHODS: One hundred seventy couples planning pregnancy enrolled from community volunteers from 2011 to 2015; women were taught the Peak Day method to identify fertile windows. Both partners collected daily urine specimens from the first day of fertile-quality fluid (estimator of the beginning of fertile window). Men discontinued on the estimated day of ovulation/conception +2 days; women continued through the onset of next menses, or positive pregnancy test at estimated day of ovulation/conception +18 days. We compared dates from samples with participants’ fertility charts to determine proportion correctly collected. Also, expert reviewers judged on which days urine should have been collected, determining investigator-identified sampling days. RESULTS: One hundred sixty-nine couples submitted 6,118 urine samples from 284 cycles. Reviewers and participants agreed in 87% of cycles for the date of the beginning of the fertile window ±3 days (65% exact-day agreement); agreement on ovulation date, ±3 days, was 93% (75% exact-day agreement). Five thousand three hundred twenty-nine female samples were expected based on investigator-identified sampling days, and 4,546 were collected, of which 82% were correctly collected on expected days. Fifty-nine percent of male samples were correctly collected relative to investigator-identified sampling days. CONCLUSIONS: Intensively-scheduled, biologically-triggered, at-home biospecimen collection can successfully be targeted to the periconceptional window and completed in a longitudinal cohort study.