title: Timing clinic visits to phases of the menstrual cycle by using a fertility monitor: the BioCycle Study.
abstract: Planning study visits during specific menstrual cycle phases is important if the exposure or outcome is influenced by hormonal variation. However, hormone profiles differ across cycles and across women. The value of using fertility monitors to time clinic visits was evaluated in the BioCycle Study (2005-2007). Women aged 18-44 years (mean, 27.4) with self-reported menstrual cycle lengths of 21-35 days were recruited in Buffalo, New York, for 2 cycles (n = 250). Participants were provided with home fertility monitors that measured urinary estrone-3-glucuronide and luteinizing hormone (LH). The women were instructed to visit the clinic for a blood draw when the monitor indicated an LH surge. The monitor recorded a surge during 76% of the first cycles and 78% of the second cycles. Scheduling visits by using set cycle days or algorithms based on cycle length, such as a midcycle window or a window determined by assuming a fixed luteal phase length, would be simpler. However, even with perfect attendance in a 3-day window, these methods would have performed poorly, capturing the monitor-detected LH surge only 37%-57% of the time. Fertility monitors appear to be useful in timing clinic visits in a compliant population with flexible schedules.
authors.affiliation: Division of Epidemiology, Statistics, and Prevention Research, the Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland, USA. penelope.howards@emory.edu
authors.forename: Penelope P
authors.initials: PP
authors.lastname: Howards
authors.forename: Enrique F
authors.initials: EF
authors.lastname: Schisterman
authors.forename: Jean
authors.initials: J
authors.lastname: Wactawski-Wende
authors.forename: Jennifer E
authors.initials: JE
authors.lastname: Reschke
authors.forename: Andrea A
authors.initials: AA
authors.lastname: Frazer
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Hovey
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood / Q000652:urine; D003625:Data Collection; D004958:Estradiol / Q000097:blood; D004970:Estrone / Q000031:analogs & derivatives* / Q000652:urine; D005260:Female; D046910:Fertile Period / Q000652:urine*; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood / Q000652:urine*; D008396:Maryland; D008597:Menstrual Cycle / Q000097:blood / Q000652:urine*; D009819:Office Visits; D010061:Ovulation Detection / Q000295:instrumentation / Q000379:methods*; D011374:Progesterone / Q000097:blood; D012189:Retrospective Studies; D013997:Time Factors; D014481:United States
chemical_list: D015415:Biomarkers; C015856:estrone-3-glucuronide; D004970:Estrone; D011374:Progesterone; D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone