Title: Anovulation after pregnancy termination: ovarian versus hypothalamic-pituitary factors.

POPLINE Document Number: 797243

Author(s):

DiZerega GS
Williams RF
Morin ML
Hogden GD

Source citation:

JOURNAL OF CLINICAL ENDOCRINOLOGY AND METABOLISM, 1979 Oct;49(4):594-9.

Abstract:

28 female rhesus monkeys were studied after induced abortion or after spontaneous delivery at term to differentiate ovarian from hypothalamic-pituitary factors responsible for suppression of ovulation. Human menopausal gonadotropin (HMG) was administered to stimulate follicular maturation, and estradiol benzoate was injected to test induction of gonadotropin surge. Spontaneous ovulation was delayed until about 39 days after abortion. The presence of multiple preovulatory follicles on both ovaries confirmed that folliculogenesis had been stimulated by HMG, which also caused the maturation and rupture of these follicles. These findings show that pregnancy does not hinder gonadotropin stimulation on the ovaries, but that it suppresses hypothalamic-pituitary responsivity to the positive feedback action of estrogen on FSH and on LH surges. It is possible that tonic gonadotropin secretion is inadequate to initiate follicular maturation until late in the puerperium.

Keywords:

Animals, Laboratory
Abortion
Anovulation
Ovarian Effects
Gonadotropins, Pituitary
Hypothalamus
Side Effects
Clinical Research
Research Methodology
Fertility Control, Postconception
Family Planning
Ovary
Genitalia, Female
Genitalia
Urogenital System
Physiology
Biology
Gonadotropins
Hormones
Endocrine System
Central Nervous System
Treatment