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Mestranol / norethindrone Pregnancy and Breastfeeding Warnings

Mestranol / norethindrone is also known as: Genora 1/50, Necon 1/50, Nelova 1/50 M, Norethin 1/50 M, Norinyl 1+50, Ortho-Novum 1/50

Medically reviewed on Mar 21, 2018

Mestranol / norethindrone Pregnancy Warnings

One case report has suggested that oral contraceptive hormones may cause choreoathetosis in infants exposed in utero.

A recent case control study has suggested a weak association between use of older high dose contraceptives (particularly those containing 1.0 mg of ethynodiol diacetate) and the occurrence of congenital limb defects. However, the authors concluded that "this weak causal relationship was probable in the past when relatively high doses of contraceptive pills were used. This risk is apparently minimized by the use of new type (e.g., D-norgestrel) and lower dose of contraceptive pills".

Oral contraceptive combinations have been assigned to pregnancy category X. Although some reports have suggested that oral contraceptive hormones may cause a variety of congenital malformations, recent studies (including a meta-analysis of prospective studies) have suggested that an association between oral contraceptive use and congenital malformations does not exist. Some progestins may cause masculinization of female infants. There is no indication for the use of oral contraceptive combinations during pregnancy. Oral contraceptive combinations are contraindicated for use during pregnancy.

See references

Mestranol / norethindrone Breastfeeding Warnings

Both the estrogens and progestins occurring in commercially available oral contraceptive formulations are excreted into human milk in very small amounts. The American Academy of Pediatrics considers use of oral contraceptive combinations to be compatible with breast-feeding despite rare reports of breast enlargement in the nursing infant and the possibility of a decrease in milk production and protein content.

Some studies have examined the effect of progestin-only contraceptives on breast-feeding. The extent to which such studies have bearing on oral contraceptive combinations is uncertain. Use of such formulations has not been reported to be associated with deleterious effects on breast-fed infants.

See references

References for pregnancy information

  1. Bracken MB "Oral contraception and congenital malformations in offspring: a review and meta-analysis of the prospective studies." Obstet Gynecol 76 (1990): 552-7
  2. Czeizel AE, Kodaj I "A changing pattern in the association of oral contraceptives and the different groups of congenital limb deficiencies." Contraception 51 (1995): 19-24
  3. Janerich DT, Piper JM, Glebatis DM "Hormones and limb-reduction deformities." Lancet 2 (1973): 96-7
  4. Profumo R, Toce S, Kotagal S "Neonatal choreoathetosis following prenatal exposure to oral contraceptives." Pediatrics 86 (1990): 648-9

References for breastfeeding information

  1. McCann MF, Moggia AV, Higgins JE, Potts M, Becker C "The effects of a progestin-only oral contraceptive (levonorgestrel 0.03 mg) on breast-feeding." Contraception 40 (1989): 635-48
  2. Kacew S "Adverse effects of drugs and chemicals in breast milk on the nursing infant." J Clin Pharmacol 33 (1993): 213-21
  3. Canto TE, Vera L, Polanco LE, Colven CE "Mini-pill in lactating women." Contraception 39 (1989): 589-601
  4. Committee on Drugs, 1992 to 1993 "The transfer of drugs and other chemicals into human milk." Pediatrics 93 (1994): 137-50

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.