['To determine whether an inter-relationship exists between endocervical mucus pH, serum androgen levels, and waist to hip (W:H) ratio.', 'Donor insemination clinic, University of Sheffield, Jessop Hospital, Sheffield, United Kingdom.', 'One hundred patients receiving donor insemination.', 'Waist, hip, height, and weight measurements were recorded for 100 patients receiving donor insemination. At the onset of the LH surge when patients attended for their first insemination, a sample of endocervical mucus and blood was taken. The Insler score of the mucus was recorded and the pH was measured with multirange pH paper. Of the 100 patients studied, 10 cases had an endocervical mucus pH < 6 despite Insler scores of > 10. Serum T, DHEAS, and androstenedione levels were measured in the 10 patients with pH < 6 and in 26 patients selected at random from the 90 patients with pH > or = 6.', 'The W:H ratio was significantly higher in the patients with pH < 6 than pH > or = 6. No significant difference was seen in body mass index between the latter groups. All serum androgen levels were significantly higher in the patients with pH < 6 than pH > or = 7.'] Is endocervical mucus pH inversely related to serum androgen levels and waist to hip ratio?