Inadequate cervical mucus--a cause of "idiopathic" infertility

Abstract

The purpose of this study was to investigate and treat a group of patients referred for "idiopathic" infertility in whom no apparent cause for infertility, apart from inadequate cervical mucus, was found. Hormone investigations revealed that these patients could be divided into two groups: those with low sex steroid profiles despite apparent ovulation, and a second group with normal sex steroid profiles. All patients were treated with ovulation-inducing agents in an attempt to produce "controlled" ovarian hyperstimulation and an improved cervical mucus. Four of six patients conceived. The rationale behind the use of ovulation-inducing agents in this situation is discussed.

PIP: This study investigated and treated 6 women ages 24-37 years with unexplained infertility. Pretreatment investigations included basal body treatment recording, serial estradiol and progesterone assays, thyroid and adrenal function tests, cervical swab for culture, assessment of cervical mucus, a postcoital test prior to or during midcycle, laparoscopy and dye hydrotubation during the follicular phase of the cycle, and endometrial biopsy. The only abnormal features detected were the cervical mucus findings and sex steriods profiles. The cervical mucus was scant or absent at midcycle in 4 patients. All patients were treated with human menopausal gonadotropin (HMG) from day 3 of the menstrual cycle until an estradiol level of 1000-1500 pg/ml was achieved, at which point a single injection of 10,000 U of human chorionic gonadotropin (HCG) was administered. Clomiphene citrate was given to patients who did not respond to this regimen. 4 of the patients (including 1 treated with HMG alone and 3 treated with clomiphene and HMG) conceived during the treatment period. Cervical mucus improved in both quantity and quality and the postcoital tests became strongly positive, showing more than 20 motile sperm/high power field. These results suggest that treatment with ovulation-inducing agents can correct both poor follicular development and inadequate cervical stimulation in women with idiopathic infertility. HMG or a combination of clamiphene citrate and HMG is preferred to clamiphene citrate alone because the latter regimen may have an adverse effect on cervical mucus.