Pituitary function in human pseudocyesis

Two young women with clinically established pseudocyesis were studied by endometrial biopsy, basal hormonal serum levels and dynamic pituitary testing. Basal serum levels of PRL and TSH were in the normal range; estradiol - 17 beta, progesterone and FSH were in the follicular phase range, but LH was in the follicular phase range in one patient and in the climateric range in the other one. The histologic assessment of the endometrial biopsies disclosed a proliferative endometrium in both patients. A group of six patients with hypothalamic amenorrhea were subjected to dynamic pituitary testing to compare results with those obtained in the two patients with pseudocyesis. The dynamic pituitary response to GnRH, TRH and metoclopramide was normal in the two patients with pseudocyesis and in the group with hypothalamic amenorrhea; moreover, challenge with estradiol benzoate (EB) in the two patients with pseudocyesis disclosed a normal positive feedback of LH. These observations and the analysis of data already published suggest that the amenorrhea of pseudocyesis is associated neither with a persistent corpus luteum nor chronic hyperprolactinemia. We suggest that an abnormality in neurotransmitter pathways results in alterations of pituitary hormone secretion. However, additional patients must be studied to prove or disprove this hypothesis.