Methyl methacrylate levels in the breast milk of a patient after total hip arthroplasty.

Blood levels of methyl methacrylate (MMA) are known to be transiently elevated in patients having undergone total hip arthroplasty using cement fixation. However, it is not known whether MMA is present in the breast milk of lactating women after this procedure. The authors studied an otherwise healthy lactating 29-year-old mother 5 months postpartum who had undergone total hip arthroplasty because of walking limitations due to congenital hip dysplasia. Less than 0.0005 micrograms/mL of MMA was found in her breast milk 36 hours after the procedure. If the negative findings in this case can be confirmed in a larger trial, the current practice of discontinuing breast-feeding after arthroplasty may be reconsidered.