Ovulation evaluation

The corpus luteum arises from the ruptured follicle and secretes progesterone, which has an important role in the estrous or menstrual cycle. Luteal progesterone is also required to maintain early pregnancy in most mammalian species, including humans (Csapo Pulkkinen, 1978). Therefore, establishment and maintenance of normal corpora luteaare essential for normal reproductive function. However, with the exception of evaluations to establish their presence or absence, these structures are not evaluated in routine testing. Increased rates of follicular atresia and oocyte toxicity may lead to premature menopause in humans. Altered follicular development, failure to ovulate or altered corpus luteum formation and function can disrupt cyclicity, reduce fertility and interfere with normal sexual behaviour. Therefore, significant increases in the rate of follicular atresia, evidence of oocyte toxicity, interference with ovulation or altered corpus luteum formation or function should be considered adverse effects. 

A loss of primary oocytes will irreversibly affect a woman s fecundity, but this is difficult to measure directly. Reproductive dysfunction can be studied by the evaluation of irregularities of menstrual cycles and onset of menarche and menopause. However, menstrual cyclicity and onset of menopause and menarche are affected by many parameters, such as age, genetics, nutritional status, stress, exercise, certain drugs and the use of contraceptives that alter endocrine feedback. The length of the menstrual cycle, particularly the follicular phase (before ovulation), can vary between individuals and may make it difficult to measure significant effects in groups of women (Burch et al., 1967 Treloar et al., 1967). 

The initial evaluation of female infertility should include a detailed history and physical examination, including a Papanicolaou cervical and vaginal smear with appropriate cervical and endocervical cultures, a search for tubal patency and endometriosis or adhesions, and assessment of ovulation and adequate luteal function.After obvious treatable abnormalities have been excluded, a menstrual history indicates further endocrine evaluation and a postcoital test helps to determine coital snfticiency (Figure 53-16 see also earlier section on irregular menses). 

In addition to the usefulness of DIA as a predictor of Down syndrome risk discussed previously, inhibin A and B measurements have found applications in ovarian cancer monitoring, disorders of ovulation, early detection of viable pregnancy following in vitro fertilization, and evaluation of male infertility. 

Bums PJ, Steiner JV, Sertich PL, Pozor MA, Tice TR, Mason DW et al. Evaluation of biodegradable microspheres for the controlled release of progesterone and estradiol in an ovulation control program for cycling mares. Journal of Equine Veterinary Science. 1993 13 521-524. 

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