by Nancy Mohrbacher, IBCLC

My own silicone breast implant was inserted twenty years ago. Since then I have breastfed three children, and during the past nine years La Leche League International has referred calls and letters to me from women from all over the world who want to be put in touch with someone who has breastfed with implants. Prior to 1990, most questions related to milk supply. Now these women’s main concern is whether their babies might be harmed by silicone leaking into their milk.

Since 1990, the media has given prominent and sensational coverage to possible health risks of breast implants. In addition to possible health risks to women with implants, recent reports have raised questions about whether exposure to implants during pregnancy and breastfeeding may put their children at risk to serious health problems. There is little research on these issues and none of it is conclusive, but some doctors and women’s groups are suggesting that breastfeeding mothers with implants wean their babies and pregnant women with implants choose artificial feeding instead.

The JAMA Study

On January 19, 1994, the Journal of the American Medical Association (JAMA) published a study of eleven children with chronic gastrointestinal disorders who were born to women with silicone breast implants. Their symptoms included abdominal pain, vomiting, difficulty in swallowing or poor weight gain. Eight of these children had been breastfed and three had been artificially fed. Six of the eight breastfed children (which were from four families) were found to have reduced esophageal motility, or a reduction in the normal wave-like motion of the esophagus that moves food toward the stomach. This reduced esophageal motility was not found in the three artificially fed children or in the 20 children with chronic gastrointestinal disorders in the control group whose mothers did not have silicone breast implants. Abnormal esophageal motility is seen in several disorders, including scleroderma, an autoimmune disease that has been linked to women with silicone breast implants in lawsuits.

The authors of this study, Drs. Jeremiah J. Levine and Norman T. Ilowite, concluded that:

Although these results will need to be verified by larger studies, it is possible that substances leaking from the implant or immunologic factors may be transmitted through breast milk and taken up across the immature intestinal barrier of the breastfeeding infant.¹

In an editorial appearing in the same issue of JAMA, pediatrician Jonathan A. Flick, MD, commented:

The American Medical Association’s Council on Scientific Affairs has estimated that it will be many years before controlled trials determine if silicone gel breast implants are associated with an increase in immune disorders among the recipients themselves. The benefits of breastfeeding, including the infant’s reduced susceptibility to infectious diseases and promotion of maternal-infant bonding, are well established, while the potential adverse effects reported by Levine and Ilowite among breastfed children of silicone implant recipients are yet to be confirmed….For now, it would appear that breast, whether augmented or not, is still best.²

The FDA Response and Others

The US Food and Drug Administration (FDA) quickly responded to this study in its January 21, 2022 Talk Paper:

FDA believes that the study is inconclusive and preliminary, and further studies are needed…The [FDA] views this study with interest, but the limitations of the study design including, for example, the small size of the study and selection bias, limit conclusions that can be drawn from it…..³

Also as a response to this study and after consultation with the FDA, the Human Milk Banking Association of North America (HMBANA) issued an addendum to its guidelines on March 8, 1994:

Although the paper in question does not offer conclusive proof of an association between silicone implants and reduced esophageal motility, the [HMBANA] has an obligation to provide the safest product possible to its recipient infants….It is recommended that mothers with silicone breast implants not be accepted as donors.⁴

According to HMBANA’s Director, Lois Arnold, MPH, IBCLC, this change in guidelines should not be taken to mean that women with breast implants should not breastfeed or that a cause-and-effect relationship has been proven between health problems in children and breastfeeding with silicone breast implants. According to Arnold, it was “a defensive measure” to insure that public confidence remains high in the safety of milk from human milk banks.

Silicone in the Milk?

Levine and Ilowite suggest in their study that if a connection exists between breastfeeding with silicone breast implants and health problems in children, it may be due to “substances leaking” into mother’s milk. To determine whether silicone implants are compatible with breastfeeding, the same questions can be asked that are used to determine a drug’s compatibility with breastfeeding.

Does it pass into the milk? In order to pass into the milk, a molecule must be small enough to fit through the water-filled pores in the lining of the mother’s alveoli, which “permit the movement of molecules of less than 200 molecular weight.”⁵ Some drugs, such as heparin, do not pass into mother’s milk, because their molecular weight is greater than 200. The type of silicone used in implants (active ingredient: polydimethylsiloxanes) has a molecular weight of 14,000 to 21,000,⁶ making it extremely unlikely that the molecules could fit through this membrane and pass into the milk.

Silicone is also insoluble in water, further decreasing the likelihood that it could pass into the milk. According to Philip O. Anderson in Clinical Pharmacy, in order for drug transfer to take place, the molecules must be soluble in water. “Larger…molecules must dissolve in the outer lipid membrane of the epithelial cells, diffuse across the aqueous interior of the cell, dissolve in and pass through the opposite cell membrane, and then pass into the milk.”⁷

Jack Northington, an analytical chemist at a California lab, developed a test for silicone in human milk and has used it to test the milk of women whose implants have ruptured, those most likely to have silicone in their milk. However, he has yet to find any silicone in milk. Northington considers the test a waste of money, explaining that “in theory [silicone] shouldn’t be there, and in practice we haven’t found it.”

If it is in the milk, would it be absorbed by the baby? Some drugs, such as insulin, are destroyed by the baby’s digestive system. Other drugs, such as some laxatives, are not absorbed and pass through a baby’s digestive system unchanged. Last year, when Betty Crase, manager of La Leche League International’s Breastfeeding Reference Library & Database, polled selected members of La Leche League International’s Health Advisory Council, their opinion was that ingested silicone would pass through a baby’s digestive system unchanged. If silicone is not absorbed, it would pose no danger to the nursing baby.

Mylicon drops, which contain the same polymer as silicone breast implants, are given to colicky babies as a gas-reducer and work by coating the digestive system.

If it is absorbed by the baby, what are safe levels? Neither normal nor safe levels of silicone have yet been established. Many people are surprised to learn that nearly everyone has silicone in his or her body. We ingest silicone compounds through cosmetics (such as lipstick), over-the-counter drugs (such as antacids), and the coating on fresh fruits and vegetables. Silicone is also used to lubricate syringes and to make silicone nipples for baby bottles and pacifiers.

Most drugs are considered compatible with breastfeeding, because the benefits of breastfeeding far outweigh the risks of a small amount of drug reaching the baby. For the same reason, silicone implants should also be considered compatible with breastfeeding.

Asking the Right Questions

Everyone agrees that more research is needed into the health effects of silicone breast implants on mothers and their babies. However, studies that focus on children with health problems, such as the one recently reported through Reuters new service in the popular press by Dr. Andrew Campbell of the Center for Immune, Environmental and Toxic Disorders in Houston as well as the JAMA study, paint a distorted picture. What we really need to know is if these health problems occur more often in children of mothers with implants or if they occur at the same rate as in children of mothers without implants. Until we have this information, we cannot know if there is a cause-and-effect relationship. And if a link is established between implants and health problems in children, we need to know if silicone exposure in utero is the cause or if breastfeeding plays a part. If further research shows that silicone compromises a baby’s immune system during pregnancy, the immunities in breastfeeding may prove to be even more important to these babies than to others.

Advising women to artificially feed their babies in the meantime is no solution. Scientific evidence exists that artificial feeding can be hazardous to babies’ health. It is common knowledge that artificially fed babies have greater morbidity and mortality than breastfed babies, and preliminary studies now indicate that the health benefits of breastfeeding may last a lifetime. Artificial feeding contributes to insulin-dependent diabetes, Crohn’s disease, celiac disease, ulcerative colitis, and some childhood cancers, as well as food allergies and chronic liver diseases.8 Unlike the concerns raised about breastfeeding with silicone breast implants, the health risks of artificial feeding are well-documented.

Until there is scientific proof to the contrary, I believe the benefits of breastfeeding with silicone breast implants still outweigh the risks and these women should be encouraged to breastfeed.

Footnotes

1. Levine J.J. and N.T. Ilowite. “Sclerodermalike Esophageal Disease in Children Breast-fed by Mothers with Silicone Breast Implants.” JAMA 1994, 271:213-16.
2. Flick, J.A. “Silicone Implants and Esophageal Dysmotility: Are Breast-fed Infants at Risk?” JAMA 1994, 271:240-41.
3. FDA Talk Paper, “Study of Children Breastfed by Women with Breast Implants.” Food and Drug Administration, U.S. Department of Health and Human Services, T94-6, January 21, 1994.
4. Addendum, Human Milk Banking Association of North America, P.O. Box 370464, Hartford, CT 06137-0464 USA, March 8, 1994.
5. Lawrence, R. Breastfeeding: A Guide for the Medical Profession, 3rd ed. St. Louis: Mosby, 1989, p. 259.
6. McEvoy, G, ed.. American Hospital Formulary Service Drug Information, Bethesda, MD: American Society of Hospital Pharmacists, 1992, p. 1720.
7. Anderson, P.O. “Drug Use during Breast-feeding.” Clin Pharmacy 1991, 10:595.
8. Cunningham, A.S., D.B. Jelliffe and E.F. P. Jelliffe. “Breast-feeding and Health Inthe 1980s: A Global Epidemiologic Review.” J Pediatr 1991, 118(5):659-66.