In women, progesterone levels are relatively low during the preovulatory phase of the menstrual cycle, rise after ovulation, and are elevated during the luteal phase, as shown in diagram below. Progesterone levels tend to be < 2 ng/ml prior to ovulation, and > 5 ng/ml after ovulation.
Results for this Gallup poll are based on telephone interviews conducted Aug. 7-Dec. 29, 2013, on the Gallup Daily tracking survey, with a random sample of 3,445 adults, aged 18-34, living in all 50 U.S. states and the District of Columbia, who report they are currently living at home with their parents.
The study will be featured in an upcoming issue of the journal Psychology and Aging. For the study, supported by a grant from the National Institutes of Health, Birditt and colleagues at Purdue and Pennsylvania State universities analyzed data on 474 parents and adult children who were at least 22 years old. The adult children lived within 50 miles of their parents.