Erratum to: Clin Orthop Relat Res DOI 10.1007/s11999-012-2398-0 In our article, High Chromium and Cobalt Levels in a Pregnant Patient with Bilateral Metal-on-Metal Hip Arthroplasties published online June 13, 2012, the patient described in the case report did not receive bilateral Birmingham Hip Resurfacing (BHR) implants (Smith & Nephew, Inc, Memphis, TN, USA). This erroneous statement was made throughout the article including in the figure legends and as the last point in Table 3. In the operative report of the first revision surgery that was available to us, the preexisting prostheses were mentioned to be McMinn prostheses leading us to the assumption that BHR implants were used. The orthopaedic surgeon who currently cares for the patient informed us that instead, Conserve® Plus Total Resurfacing Implants (Wright Medical Technology, Inc, Arlington, TN, USA) were implanted. We regret this error.
Background Metal-on-metal bearings frequently are used in young patients leading to the concern that disseminated metals such as chromium (Cr) and cobalt (Co) as the main constituents could affect pregnancies. Case Description We describe a 41-year-old patient with bilateral metal-on-metal hip arthroplasties, a recurrent pseudotumor, and extremely high blood levels (Cr 39 μg/L, Co 138 μg/L) at 12 gestational weeks. At different gestational weeks, maternal blood, aspirate of the pseudotumor, and amniotic fluid were analyzed for Cr and Co. Therapy with chelating agents was not recommended because the mother showed no symptoms of toxicity and the safety of chelating therapy during pregnancy is not established. At 38 weeks of gestation, a healthy male infant was delivered with elevated Cr and Co cord blood levels. At the age of 8 weeks, the infant's Cr was comparable to the cord blood level, whereas the Co decreased considerably without treatment. At the age of 14 weeks, the infant's development was seemingly uneventful and no signs of toxicity were obvious. Literature Review Carcinogenic, mutagenic, and teratogenic potentials of these metals have been suggested. However, we found no published clinical observations in context with pregnancies of women with hip arthroplasties using metal-on-metal implants. To our knowledge, this is the first report of such high levels of Cr and Co in a human pregnancy. Purposes and Clinical Relevance Although we cannot generalize from one case, the seemingly uneventful outcome of this pregnancy may reassure colleagues when counseling patients with high ion levels whether to carry a pregnancy to term.
Methylphenidate is a central nervous system stimulant medicinally used in the treatment of attention-deficit disorder with or without hyperactivity (ADD/ADHD). Data on its use in human pregnancy are limited. The primary objective of the study was to evaluate the risk of major congenital anomalies after pregnancy exposure to methylphenidate for medical indications.In a prospective, comparative, multicenter observational study performed in 4 participating Teratology Information Services (in Jerusalem, Berlin, Newcastle upon Tyne, and Toronto) between 1996 and 2013, methylphenidate-exposed pregnancies were compared with pregnancies counseled for nonteratogenic exposure (NTE) after matching by maternal age, gestational age, and year at initial contact.382 methylphenidate-exposed pregnancies (89.5% in the first trimester) were followed up. The overall rate of major congenital anomalies was similar between the groups (10/309 = 3.2% [methylphenidate] vs 13/358 = 3.6% [NTE], P = .780). The rates of major congenital anomalies (6/247 = 2.4% [methylphenidate] vs 12/358 = 3.4% [NTE], P = .511) and cardiovascular anomalies (2/247 = 0.8% [methylphenidate] vs 3/358 = 0.8% [NTE], P = .970) were also similar after exclusion of genetic or cytogenetic anomalies and limiting methylphenidate exposure to the period of organogenesis (weeks 4-13 after the last menstrual period). There was a higher rate of miscarriages and elective terminations of pregnancy in the methylphenidate group. Significant predictors for the miscarriages using Cox proportional hazards model were methylphenidate exposure (adjusted hazard ratio [HR] = 1.98; 95% CI, 1.23-3.20; P = .005) and past miscarriage (adjusted HR = 1.35; 95% CI, 1.18-1.55; P < .001).The present study suggests that methylphenidate does not seem to increase the risk for major malformations. Further studies are required to establish its pregnancy safety and its possible association with miscarriages.
