Prediction and Detection of Ovulation

Abstract

This paper reviews and evaluates various methods for the prediction and detection of ovulation, with emphasis on the role this plays in management of infertility and in natural family planning. After spelling out the hormonal events which control the ovulatory process, techniques for ovulation detection and timing are discussed. These fall into 2 classifications: 1) direct assays of gonadotropins or steroid hormones in the serum or urine; and 2) evaluation of peripheral changes preceding, coinciding with, or succeeding ovulation. Since serial hormone assays are not practical in routine clinical practice, clinicians generally rely on peripheral or end-organ changes to determine alteration in circulating steroid hermone levels, but direct assays of gonadotropins and sex steroids would have to supplement these methods to determine the accuracy of commonly performed methods of ovulation detection. Tests based on hormone assays include daily assays of 1) serum or urinary lutienizing hormone (LH), 2) urinary estrogens (or estrogen metabolites) or serum estradiol, and 3) serum progesterone or urinary pregnanediol. Each assay is described in the text. Tests based on peripheral and systemic changes include ]) basal body temperature changes, 2) tests of physical properties of cervical mucus (appearance, spinnbarkheit, ferning, and burn test), 3) tests of the chemical content of cervical mucus (protein constituents and enzymes), 4) endometrial biopsy, 5) vaginal cytology, and 6) saliva sampling (measuring alkaline phosphatase levels which generally increase at time of ovulation). Tests based on hematologic changes, especially the decrease of blood basophil count at ovulation, are also discussed. Among the possible techniques of natural family planning discussed are the calendar method (Ogino-Knaus), the cervical mucus (ovulation) method, and the symptothermic method (basal temperature and calender combined) method.