Reproductive failure in mice chronically infected with Toxoplasma gondii.

Nya: NYLAR female mice infected with Toxoplasma gondii for 1 and 2 months were cohabited with normal males for 1 week, then sequestered individually to monitor their reproductive performance. Mice bred 1 month postinfection (p.i.) exhibited reproductive failure, with 1 of 16 females delivering 2 sickly pups; in others, interruption of pregnancy and fetal wastage occurred. Mice infected for 2 months were uniformly infertile. Vaginal lavage showed cessation of estrus cycling and constant diestrus cytology at as early as 1 month p.i. Histologic examination of the ovaries revealed impaired folliculogenesis and few corpora lutea, if any. Uterine atrophy was marked. Coronal sections of the cerebrum disclosed widespread vasculitis, focal disruptions of the ependymal cell layer lining the lateral and third ventricles, and periventricular edema. We suggest that the reproductive failure of the infected mice is due to an acquired hypogonadotropic hypogonadism secondary to hypothalamic dysfunction.