Intrauterine insemination for infertility due to cystic fibrosis

Mild CF is not associated with increased obstetric risk to patients or offspring. These patients can be identified on the basis of Shwachman-Kulczycki scores, nutritional status, normal chest x-ray and pulmonary function tests, normal lung volumes, and mild to moderate airway obstruction. Spontaneous pregnancy has been achieved in women with CF, but they appear to have a decreased fertility. One possible cause in mild disease is a cervical factor due to abnormal viscous mucus. This mucus has been shown to fail to hydrate, and at midcycle contains less than 80% water, whereas 93% to 96% hydration appears to be necessary for sperm migration. Cyclic electrolyte changes in cervical mucus are not noted in CF patients, and sodium concentration in dry residue at midcycle is 10% of normal. Intrauterine insemination with a washed sperm fraction offers a theoretically safe method of bypassing this barrier. Preliminary data have revealed that this may be a useful therapy in other cases of infertility in which the abnormality is an unexplained, negative postcoital test. CF patients should be carefully evaluated and advised of risks before becoming pregnant. In cases of mild CF in which no factor for infertility exists other than consistently abnormal cervical mucus, intrauterine insemination with washed motile sperm may be beneficial. We believe this to be the first case of a CF patient successfully treated in this manner.