title: Application of a method for estimating day of ovulation using urinary estrogen and progesterone metabolites.
abstract: Longitudinal epidemiologic studies of menstrual and reproductive function are more informative if one can identify day of ovulation. We previously developed a method for estimating day of ovulation that is feasible for epidemiologic studies. The method relies on the relative concentrations of estrogen and progesterone metabolites in daily first-morning urine specimens and does not require creatinine adjustment. This paper describes results of applying this method to a large study with 724 menstrual cycles from 217 women. The method estimated a credible day of ovulation in 88% of cycles. Missing data accounted for most of the failures. When we excluded anovulatory cycles (1%) and cycles with missing data, the method estimated a day of ovulation in 97% of cycles. Variance in luteal phase length was small for our sample, suggesting that this method of identifying a day of ovulation introduces no more measurement error than when day of ovulation is determined by plasma luteinizing hormone (LH), the standard clinical method.
authors.affiliation: Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA.
authors.forename: D D
authors.initials: DD
authors.lastname: Baird
authors.forename: D R
authors.initials: DR
authors.lastname: McConnaughey
authors.forename: C R
authors.initials: CR
authors.lastname: Weinberg
authors.forename: P I
authors.initials: PI
authors.lastname: Musey
authors.forename: D C
authors.initials: DC
authors.lastname: Collins
authors.forename: J S
authors.initials: JS
authors.lastname: Kesner
authors.forename: E A
authors.initials: EA
authors.lastname: Knecht
authors.forename: A J
authors.initials: AJ
authors.lastname: Wilcox
mesh_terms: D000328:Adult; D000465:Algorithms; D015415:Biomarkers / Q000652:urine; D004966:Estrogens, Conjugated (USP) / Q000652:urine; D004970:Estrone / Q000031:analogs & derivatives* / Q000652:urine; D005069:Evaluation Studies as Topic; D005260:Female; D005498:Follicular Phase; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood; D008597:Menstrual Cycle; D010060:Ovulation / Q000097:blood / Q000652:urine*; D010061:Ovulation Detection / Q000379:methods*; D011247:Pregnancy; D011276:Pregnanediol / Q000031:analogs & derivatives* / Q000652:urine; D011863:Radioimmunoassay
chemical_list: D015415:Biomarkers; D004966:Estrogens, Conjugated (USP); C022270:pregnanediol-3 alpha-glucuronide; C015856:estrone-3-glucuronide; D004970:Estrone; D007986:Luteinizing Hormone; D011276:Pregnanediol