Plasma prolactin/oestradiol ratio at 38 weeks gestation predicts the duration of lactational amenorrhoea

Abstract

At 38 weeks gestation, the ratio PRL/oestradiol identified all individual women according to the subsequent duration of their lactational amenorrhoea, suggesting that duration of lactational amenorrhoea is conditioned during pregnancy.

Associations of body size and reproductive factors with circulating levels of sex hormones and prolactin in premenopausal Japanese women

“…Some associations were somewhat strengthened; the means of total estradiol and estrone were 39.7 and 43.8% lower, respectively, in women with a BMI of 324 kg/m 2 g than in those with a BMI of \18 kg/m 2 (p for trends were 0.004 and 0.02, respectively). Exercise was significantly inversely associated with total testosterone (p = 0.046) and free testosterone (p = 0.03).…”

“…Lower androgen, as well as lower prolactin levels, could potentially contribute to the decreased risk of breast cancer among women who had delivered or breastfed. We cannot exclude the possibility that the prolactin or androgen profile before or during pregnancy may be the primary factor determining lactation performance or the ability to have children [38,39].…”

Fertility

“…The period of breastfeeding is lower in economically developed populations. The length of infecundability is longer in rural area and uneducated women (Campino et al 2001). This is an addable factor which affects the conception and the rate of fertility among different societies.…”

Reproductive Function During Lactation

“…17 The inhibition of dopamine secretion from the hypothalamus has been associated with the neural impulses from stimulation of the nipple during lactation. Campinos et al 17 followed 17 women at 34 and 38 weeks' gestation who fully breastfed for at least 6 months.…”

“…17 Data were analyzed separately for IUDs inserted immediately after birth (within 10 minutes of placental expulsion). 17 Data were analyzed separately for IUDs inserted immediately after birth (within 10 minutes of placental expulsion).…”