ABSTRACT
Evaluation of luteal phase function is an important part of fertility evaluation in the female. Among fifty clinically identified patients with primary infertility certain well-established laboratory methods were used to identify the luteal phase defect. These methods included serum progesterone assays, endometrial biopsy, vaginal cytology, basal body temperatures and cervical mucus scoring, with appropriate controls. Based on both endometrial biopsy which was two or more days out of phase and the serum progesterone level of less than 2.5 ng/ml, luteal phase defect was found in five patients among the 50 patients (10 percent). It was found that an endometrial biopsy which was well dated showed a definite correlation with the progesterone assays and could be considered as the most easily performed and reliable indicator, useful in detecting a luteal phase defect.