Neuroendocrine mechanisms of lactational infertility in women
Biol. Res
; 28(2): 155-63, 1995.
Article
en En
| LILACS
| ID: lil-228559
Biblioteca responsable:
BR1.1
ABSTRACT
The current knowledge on the mechanisms of lactational infertility, discussed during a symposium of investigators in this subject, is reviewed. Three periods of lactation are examined the first weeks postpartum, the period of extended lactational amenorrhea and the recovery of ovarian function. In the first postpartum weeks the inhibition of ovarian function is accounted by diminished pituitary response to GnRH, since exogenous GnRH fails to elicit a LH increase. Suckling can extend the period of ovarian inhibition for weeks, months or years, although it does not fully suppress pulsatile secretion of LH beyond the first weeks. Extended lactational amenorrhea is associated with low LH plasma levels, a great PRL increase in response to suckling, low basal E2 levels and a suppression of estrogen positive feedback. Decreased immunoreactive LH levels may result from partial suppression of the LH pulse generator and a smaller mass of GnRH released in each burst. The role of neurotransmitters, PRL and ovarian factors is discussed. After the recovery of ovulatory cycles suckling still has a residual infertility effect, associated to inadequate luteal function. The sources of variation among women and populations were recognized. Areas in which research is needed to improve the understanding of the mechanisms that sustain lactational amenorrhea are suggested
Buscar en Google
Colección:
01-internacional
Base de datos:
LILACS
Asunto principal:
Lactancia
/
Periodo Posparto
Límite:
Adult
/
Female
/
Humans
/
Pregnancy
Idioma:
En
Revista:
Biol. Res
Asunto de la revista:
BIOLOGIA
Año:
1995
Tipo del documento:
Article
País de afiliación:
Brasil
Pais de publicación:
Chile