Silicon, Silicone, Breastfeeding, and Breast Implants

Pediatrics, November 2002

To the Editor–

More than 200,000 breast implant augmentation procedures are performed annually in the United States, most on teenagers and young women of reproductive age.1 As a result, many nursing mothers have breast implants –all composed at least in part of silicone.

The American Academy of Pediatrics (AAP) policy statement on silicone breast implants and breastfeeding concluded that the “Committee on Drugs does not feel that the evidence currently justifies classifying silicone implants as a contraindication to breastfeeding.”2 We agree that there is a lack of data to contraindicate breastfeeding by women with breast implants, but there are also no convincing data providing it is safe. The available studies have too many methodological shortcomings, and this problem is apparent in the 3 reports cited by the policy statement as evidence supporting the safety of breastfeeding by mothers with breast implants.3-5

The AAP statement quotes one study, by Semple et al.4, to note that “silicon is present in higher concentrations in cow milk and formula than in milk of humans with implants.”2 That may be true, but silicon differs substantially from silicone, and silicon levels are not an adequate measure of silicone content of breast milk.6 Silicone is an organic polymer that contains elemental silicon, and silicone is not biologically inert.7 It is unknown what long-term effects silicone ingested through breast milk will have on the health of nursing infants.

A second study cited by the AAP policy statement directly assayed silicone polymer and found that silicone levels in the milk of women with implants were not significantly different from those in control human milk samples.5 However, only 6 samples of milk from lactating women with breast implants were obtained– a sample too small to permit broad generalizations. Silicone is known to leak from breast implants when they are intact, and even more when ruptured.8 The highly variable condition of breast implants can cause significant variation in the silicone content of breast milk.

The third study cited by the AAP statement purports to demonstrate no increased risk for connective tissue diseases or congenital malformations among children of mothers with breast implants. However, it included only 279 children born after their mothers received breast implants. That sample size is too small to adequately study the incidence of such uncommon disorders.

Breastfeeding confers numerous benefits on nursing infants9 and physicians should continue encouraging the practice. However, the safety of breastfeeding by women with silicone breast implants has not been adequately studied — a fact these women should be told. We urge the AAP to revise their policy statement to acknowledge the lack of safety data. More importantly, additional studies need to be conducted on this very important issue.

Jae Hong Lee, MD, MPH
Diana Zuckerman, Ph.D
National Center for Policy Research for Women & Families
Washington, DC 20006

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1 National Plastic Surgery Statistics: Cosmetic and Reconstructive Plastic Surgery. The American Society of Plastic Surgeons. Available at http://www.plasticsurgery.org/mediactr/natstats2001.cfm. Accessed May 8, 2002.

2 American Academy of Pediatrics, Committee on Drugs. The transfer of drugs and other chemicals into human milk. Pediatrics. 2001;108:776-789.

3 Kjoller K, McLaughlin JK, Friis S, et al. Health outcomes in offspring of mothers with breast implants. Pediatrics. 1998; 102:1112-1115.

4 Semple JL, Lugowski SJ, Baines CJ, et al. Breast milk contamination and siliconeimplants: preliminary results using silicon as a proxy measurement for silicone. Plast Reconstr Surg. 1998; 102:528-533.

5 Berlin CM, Jr. Seilicone breast implants and breastfeeding. Pediatrics. 1994; 94:547-549.

6 LeVier et al. What is silicone? Plas Reconstr Surg. 1993: 92:163-167.

7 Bondurant S, Ernster V., Herdman R. eds. Safety of Silicone Breast Implants. Washington, DC: National Academy Press, 2000.

8 Beekman, WH, Feitz, R. Hage JJ, et al, Life span of silicone gel-filled mammary prostheses. Plast Reconstr Surg. 1997; 100: 1723-1726.

9 AAP, Work Group on Breastfeeding. Breastfeeding and the use of human milk. Pediatrics. 1997; 100:1035-1039.