美雌醇 + 异炔诺酮

Combination contraceptive containing oestrogen (Mestranol) and progestogen (Noretinodrel) in the form of oral pills. It was the first contraceptive to be marketed (1959). Currently withdrawn from the market.

MESTRANOL: a synthetic estrogen that is metabolised to ethinylestradiol, which has similar actions to estradiol.

• At the date of the last update, we found no published data on the excretion of mestranol in breast milk, but its metabolite, ethinylestradiol, is excreted in negligible or no amounts in breast milk.
• There is evidence (although not consistent) that oestrogens may decrease milk production, especially during the first few weeks postpartum and at doses equal to or greater than 30 micrograms per day of ethinylestradiol. It may decrease the protein content of breast milk.
• No problems have been observed in infants whose mothers took mestranol, except for one isolated case of transient gynaecomastia in an infant. ^{(Curtis 1964)}

NORETINODREL is a progestogen similar to norethindrone.

• It is excreted in breast milk in clinically insignificant amounts ^{(Laumas 1967, Pincus 1966)} and no problems have been observed in infants whose mothers took it.

Breastfeeding rates are better when taking a progestogen-only hormonal contraceptive than when taking a combined oestrogen-progestogen contraceptive. ^{(Goulding 2018)} 

During breastfeeding, progestogen-only contraceptives are preferable to those combined with oestrogen and, in this case, those with lower oestrogen doses. ^{(CDC 2016, WHO/OMS 2015, Altshuler 2015, Berens 2015, CLM 2012, Moretti 2000)}

During the first 4-6 weeks postpartum, non-hormonal methods are the first choice, followed by IUDs and progestogen implants. ^{(Berens 2015, Mwalwanda 2013, Rowe 2013, CLM 2012)}