Mestranol + Chlormadinone

Birth control pill that contains the combination of an estrogen (Mestranol) and a progestin (Cholrmadinone) for oral use. Mestranol is a synthetic estrogen that is metabolized to Ethinylestradiol with similar actions as estradiol. A latest update no published data on excretion in breast milk, found were found. However, it is known that its metabolite Ethinylestradiol is excreted into milk in no or small amount. There is evidence (albeit inconsistent) that estrogen-containing pills may decrease milk production, especially during the first few weeks postpartum with a daily dose above 30 micrograms of ethinyl estradiol. It may reduce the protein content of the milk. No problems have been observed in infants whose mothers were treated, except one isolated case of transient gynecomastia.

Chlormadinone is a synthetic progestin that is similar to progesterone.

At the date of the last update we did not find any published data on its excretion in breast milk.

Other related progestin drugs are excreted into breast milk in clinically non-significant amount ^{(Croxatto 1987, Betrabet 1987, Nilsson 1977)} and no problems have been observed in infants whose mothers were treated with this medication. ^{(Roy 2020, Bahamondes 2013, Dutta 2013, Shaamash 2005, Bjarnadóttir 2001, Díaz 1987)}

No changes in prolactin levels or alterations in milk production or composition have been observed in women treated with chlormadinone ^{(Talwar 1977, Beck 1976, Sammour 1973, González 1970, Howard 1969, Martínez 1967)}, except for a slight decrease in the amount of proteins.^{(Sammour 1973)}

 

With other similar combined contraceptives no differences have been observed in the frequency of breastfeeding or the amount of milk produced or weight gain of breastfed infants compared to other contraceptive methods (intrauterine devices, isolated progestogens). However, it would be advisable to avoid them until breastfeeding is well established (4-6 weeks). During lactation, progestin-only contraceptive pills are preferred to Estrogen containing ones, otherwise, the lowest estrogen dose should be used Within the first 6 postpartum weeks, non-hormonal methods are in the first line of choice. Hormone containing contraceptives do not affect the composition of milk, minerals (Mg, Fe, Cu, Ca, P) fat, lactose and calories but only a few the proteins.