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Segesterone use while Breastfeeding

Drugs containing Segesterone: Annovera

Medically reviewed by Drugs.com. Last updated on Apr 4, 2021.

Segesterone Levels and Effects while Breastfeeding

Summary of Use during Lactation

Segesterone acetate is available in the United States in a combination contraceptive vaginal ring (Annovera) that releases segesterone acetate and ethinyl estradiol. No information is available on the use of this product during breastfeeding; however, segesterone is poorly bioavailable orally, so systemic exposure to segesterone in breastfed infants will be minimal. No special precautions are necessary during breastfeeding.

Based on the available evidence, expert opinion in the United States holds that because of the clotting risk, combination contraceptive products should not be used before 3 weeks postpartum. Between 3 weeks and 6 months postpartum, the advantages of using the method generally outweigh the theoretical or proven risks, although the evidence of lack of effect on lactation is poor and does not include preterm or ill infants. After 6 months postpartum, combination contraceptives, including oral tablets, the transdermal patch and vaginal ring, can be used, but progestin-only methods are preferred if breastfeeding will be continued.[1] World Health Organization guidelines are more restrictive, stating that combined oral contraceptives should not be used in nursing mothers before 42 days postpartum and the disadvantages of using the method generally outweigh the advantages between 6 weeks and 6 months postpartum.[2] The manufacturer of Annovera recommends that another form of contraception should be used until breastfeeding is discontinued.

Drug Levels

Maternal Levels. Six postpartum women who were breastfeeding their infants were given subdermal implants containing 20 mg of segesterone acetate. Paired milk and plasma samples were obtained at about 2 weeks after insertion and at 10-day intervals for up to 2 additional times. Among 13 milk samples, the mean segesterone concentration was 37.5 ng/L (range 7 to 73 ng/L).[3]

Sixty-six postpartum women who were fully breastfeeding their infants were given subdermal implants containing 50 mg of segesterone acetate. A breastmilk sample was obtained at 75 days post-insertion from 24 of the women. The average milk level was 138 ng/L (range 73 to 237 ng/L).[4]

One hundred postpartum women who were fully breastfeeding their infants were given subdermal implants containing 80 mg of segesterone acetate at 55 to 60 days postpartum. The implants released about 100 mcg of segesterone acetate daily. Breastmilk samples were obtained from 14 of the women once weekly for the first month after implant insertion, then every 2 weeks until weaning. Milk segesterone levels ranged from 20 to 50 ng/L. The authors estimated that the dose transferred to the infant, assuming a daily intake of 800 mL of milk, was about 50 ng daily in the first month after insertion, decreasing to around 20 ng daily thereafter.[5]

Infant Levels. Sixty-six postpartum women who were fully breastfeeding their infants were given subdermal implants containing 50 mg of segesterone acetate. An infant blood sample was obtained at 75 days post-insertion from 25 of the infants. The average infant serum level was 7 ng/L (range <5 to 20 ng/L).[4]

Effects in Breastfed Infants

Relevant published information on segesterone acetate and ethinylestradiol vaginal insert was not found as of the revision date. Studies on the use of segesterone acetate implants have found no adverse effects on growth and development.[4,5]

Effects on Lactation and Breastmilk

Relevant published information was not found as of the revision date.

References

1.
Farr S, Folger SG, Paulen M, et al. U. S. medical eligibility criteria for contraceptive use, 2010: Adapted from the World Health Organization medical eligibility criteria for contraceptive use, 4th edition. MMWR Recomm Rep 2010;59 (RR-4):1-86. PMID: 20559203.
2.
World Health Organization Department of Reproductive Health and Research. Medical eligibility criteria for contraceptive use: Executive summary. Fifth ed. Geneva. 2015. PMID: 26447268. [PubMed: 26447268]
3.
Lähteenmäki PL, Díaz S, Miranda P, et al. Milk and plasma concentrations of the progestin ST-1435 in women treated parenterally with ST-1435. Contraception. 1990;42:555–62. [PubMed: 2272183]
4.
Coutinho EM, Athayde C, Dantas C, et al. Use of a single implant of elcometrine (ST-1435), a nonorally active progestin, as a long acting contraceptive for postpartum nursing women. Contraception. 1999;59:115–22. [PubMed: 10361626]
5.
Massai MR, Díaz S, Quinteros E, et al. Contraceptive efficacy and clinical performance of Nestorone implants in postpartum women. Contraception. 2001;64:369–76. [PubMed: 11834236]

Substance Identification

Substance Name

Segesterone

CAS Registry Number

7690-08-6

Drug Class

Breast Feeding

Lactation

Contraceptive Agents, Female

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