Transfer of norethisterone(NET) and levonorgestrel(LNG) from a singie tablet into the infant's circulation through the mother's milk

Mixture effects of levonorgestrel and ethinylestradiol: Estrogenic biomarkers and hormone receptor mRNA expression during sexual programming

“…The highest LNG concentration in the present study was recently shown to permanently inhibit oocyte and oviduct development in the X. tropicalis test system (Kvarnryd et al, 2011). The progestin/estrogen ratio in the highest co-exposure treatment was 10 which is within the range of ratios used in contraceptive pills (i.e., ratios of 3-100) (Betrabet et al, 1987).…”

“…Contraceptives are frequently prescribed to nursing women (Erwin, 1994;Espey et al, 2006;Kapp and Curtis, 2010) and both progestins and estrogens are transferred to the infant via the mother's milk (Betrabet et al, 1987;Nilsson et al, 1978). However, there are large uncertainties regarding the consequences of progestin exposure via breast milk for the neurologic and sexual development of the infant (WHO, 2010).…”

Distribution of progesterone receptor immunoreactivity in the midbrain and hindbrain of postnatal rats

“…The perinatal female ovary begins to secrete progesterone after the first week of life (Schlegel et al, 1967;Quattropani and Weisz, 1973;Greco and Payne, 1994). However, the developing brain of both males and females may be exposed to significant levels of progesterone deriving from maternal sources (Pepe and Rothchild, 1974;Martin et al, 1977;Sanyal, 1978;Betrabet et al, 1987;Toddywalla et al, 1995;Quadros and Wagner, 1999) or through the de novo synthesis of progesterone from cholesterol within the developing brain itself (Compagnone et al, 1995a,b;Kohchi et al, 1998;Ukena et al, 1998Ukena et al, , 1999.…”

“…Although the perinatal ovary is quiescent until the second week of life (Schlegel et al, 1967;Quattropani and Weisz, 1973;Greco and Payne, 1994), there appear to be at least two alternate sources of progesterone: the maternal ovary and/or de novo synthesis within the developing brain itself. Maternal progesterone levels are high, not only during gestation, but also during lactation (Pepe and Rothchild, 1974;Martin et al, 1977;Sanyal, 1978;Quadros and Wagner, 1999) and progesterone may pass to neonates through mother's milk (Betrabet et al, 1987;Toddywalla et al, 1995). In addition, the perinatal rodent brain expresses all the enzymes necessary for the de novo synthesis of progesterone from cholesterol (Compagnone et al, 1995a;Kohchi et al, 1998;Ukena et al, 1998;Zwain and Yen, 1999), potentially producing locally high concentrations of progesterone within specific brain regions.…”

At what ‘infant-age’ can levonorgestrel contraceptives be recommended to nursing mothers?

“…Levonorgestrel (LNG) is the most widely used LDP by breastfeeding mothers. Like all drugs taken by breastfeeding mothers, LNG is also transferred to breast milk [3,4]. However, while other therapeutic drugs are taken for short or long periods by breasffeeding mothers for their illness, contraceptive drugs like LNG are taken by healthy breastfeeding mothers for a protracted period of time.…”