Is methylmethacrylate toxic during pregnancy and breastfeeding?--- a systematic review

Abstract

Introduction Methyl methacrylate (MMA) is commonly used in the fields of dentistry and orthopaedic surgery. However, there remain concerns for the occupational hazards of MMA, particularly during pregnancy and breastfeeding. Methods We performed a systematic review of studies on effects that MMA may have in pregnancy in the context of exposure during orthopaedic surgery and dentistry. Review articles, studies lacking statistical data, single case reports and other evidence level V studies were excluded. Results Nine studies were included. One basic science study demonstrated an increase in neuronal cell lysis and shrunken cell bodies when neocortical neurons were exposed to MMA monomer. Three animal studies exposed pregnant rodents to MMA via intraperitoneal injection or inhalation. Exposed fetuses in two studies had an increase in gross abnormalities such as hemangiomas, while there was no increase in teratologic effects in the third study. In dental workers exposed to MMA, two retrospective cohort studies did not find a statistically significant increase in birth defects or miscarriage. After exposure to MMA during total joint arthroplasty, two studies found that MMA levels were undetectable in the mothers’ serum or breast milk. One study measuring the airborne levels of MMA during simulated joint arthroplasty found that concentrations never exceeded 1% of the recommended limit set forth by the Occupational Safety and Health Administration (OSHA). Conclusions Potential teratologic effects of MMA cannot be excluded by existing evidence. However, the typical MMA exposure levels for dental and orthopaedic personnel appear to be substantially less than currently proposed exposure limits.

Pregnancy, parenthood, and fertility in the orthopaedic surgeon

“…A recent systematic review including animal studies across dentistry and orthopaedics concluded that the potential teratological effects of PMMA could not be excluded by existing evidence; however, the typical PMMA exposure levels appear to be substantially less than currently proposed limits. 41 A number of barriers to pregnancy were identified in our review, including the attitudes/perceptions of colleagues and TPDs, the cost of maternity leave, and the lack of formal policies on maternity leave and breastfeeding, particularly in the USA. In the UK and USA, there are now formal policies in place for doctors who are breastfeeding to be provided with the appropriate facilities for lactation, and adequate refrigerated storage for breastmilk.…”

“…A recent systematic review including animal studies across dentistry and orthopaedics concluded that the potential teratological effects of PMMA could not be excluded by existing evidence; however, the typical PMMA exposure levels appear to be substantially less than currently proposed limits. 41…”

Bone Cement Fumes Generated in Laminar Airflow Versus Conventionally Ventilated Operating Rooms

“…In a survey of 248 female orthopaedic surgeons, 41.7% of respondents reported that they would leave the room if PMMA cement were being used while they were pregnant, and 24.7% would choose to leave the room if they were actively breastfeeding 14 . Further, although no studies have linked MMA exposure to teratogenic effects, the potential for birth defects caused by MMA cannot be excluded 3 . Although it has been shown that exposure to MMA in the operative setting does not lead to increased levels of MMA in breast milk or in serum, the concerns regarding occupational exposure to MMA are still present 15 .…”

“…Occupational Safety and Health Administration (OSHA)permissible exposure limits of 100 ppm for an 8-hour period, these fumes are considered an occupational hazard, particularly to individuals who are pregnant 3,4 . Therefore, the reduction of MMA vapor emissions is desirable.…”

“…MMA is a colorless, clear, flammable liquid of intense odor, and its concentration in the immediate breathing zone can vary considerably in the operative setting 2 . Although MMA is noncarcinogenic and fume concentrations in dental and orthopaedic procedures typically remain below U.S. Occupational Safety and Health Administration (OSHA)-permissible exposure limits of 100 ppm for an 8-hour period, these fumes are considered an occupational hazard, particularly to individuals who are pregnant 3,4 . Therefore, the reduction of MMA vapor emissions is desirable.…”