Lifestyle and reproductive factors associated with follicular phase length.
OBJECTIVE
Variability in menstrual cycle length, largely determined by variation in follicular phase length, is related to several health outcomes, yet the causes of this variability are incompletely understood. We sought to identify characteristics associated with follicular phase length.


METHODS
We used the North Carolina Early Pregnancy Study to describe factors correlated with timing of ovulation (follicular phase length). Women collected daily urine specimens and recorded vaginal bleeding. Specimens were assayed for estrone 3-glucuronide and pregnanediol 3-glucuronide, which in turn were used to estimate the day of ovulation. All other variables were assessed through interview. Associations with follicular phase length were evaluated using a multiple regression model.


RESULTS
We determined follicular phase length for the first cycles of 201 women. Women with a history of miscarriage tended to have shorter follicular phases (2.2 days). Longer duration of oral contraceptive (OC) use and recent OC use (in the last 90 days) were both correlated with longer follicular phase. Occasional marijuana users (up to three times in the last 3 months) had a longer follicular phase than nonusers (3.5 days); the follicular phase in frequent users (more than three times) was almost 2 days longer than that of nonusers.


CONCLUSIONS
The association between marijuana use and longer follicular phase is consistent with prior rhesus monkey research that shows ovulatory delay or inhibition.
Jukic
Anne Marie Zaura
AM
Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA. jukica@niehs.nih.gov
Weinberg
Clarice R
CR
Baird
Donna D
DD
Wilcox
Allen J
AJ
D000328:Adult; D015415:Biomarkers / Q000652:urine; D004970:Estrone / Q000652:urine; D005260:Female; D005498:Follicular Phase / Q000187:drug effects / Q000652:urine*; D006801:Humans; D008019:Life Style; D008183:Luteal Phase / Q000652:urine; D002189:Marijuana Abuse / Q000652:urine*; D008597:Menstrual Cycle / Q000652:urine; D008599:Menstruation Disturbances / Q000209:etiology / Q000652:urine*; D010060:Ovulation / Q000187:drug effects / Q000652:urine*; D011276:Pregnanediol / Q000031:analogs & derivatives / Q000652:urine; D011795:Surveys and Questionnaires; D016387:Women's Health
D015415:Biomarkers; C022270:pregnanediol-3 alpha-glucuronide; D004970:Estrone; D011276:Pregnanediol