Maternal nickel exposure and congenital musculoskeletal defects.
OBJECTIVE
To investigate whether women occupationally exposed to nickel in early pregnancy are at elevated risk of delivering a newborn with a malformation or deformation of the musculoskeletal system (ICD-10: Q65-Q79).


METHODS
Data about the newborn, maternal occupation and workplace were obtained using the Kola Birth Register (KBR). Each record in the KBR was assigned a categorical nickel (Ni) exposure rating according to the occupation the delivering woman had at the time of becoming pregnant. This was achieved by using as a guideline the water-soluble Ni subfraction of the inhalable aerosol fraction obtained by personal monitoring for nickel- and copper-refinery workers or/and measured urinary-Ni concentrations. The reference population was delivering women from the source population with background exposure level. In total, the study population consisted of 22,965 births.


RESULTS
Three hundred and four infants (13.3/1,000 births; 95% confidence interval (CI): 11.9-14.7) were diagnosed with isolated musculoskeletal defect(s) at birth. The adjusted odds ratio for the association between the maternal exposure to Ni and this outcome was 0.96 (95% CI: 0.76-1.21) per unit increase in exposure category.


CONCLUSIONS
The incidence of defects in the musculoskeletal system at birth was high, especially for feet deformities, but we found no effect of maternal exposure to water-soluble Ni on the risk of delivering a newborn with a defect. However, the incidence among women working in the copper refinery was higher than in the other employment groups.
Vaktskjold
Arild
A
Nordic School of Public Health, Goöteborg, Sweden (a subsidiary of the Nordic Council of Ministers, Copenhagen, Denmark). arild.vaktskjold@nhv.se
Arild
Vaktskjold
V
Talykova
Ljudmila Vasiljevna
LV
Ljudmila Vasiljevna
Talykova
T
Chashchin
Valerij Petrovitsj
VP
Valerij Petrovitsj
Chashchin
C
Odland
Jon Oyvind
JO
Jon Oyvind
Odland
O
Nieboer
Evert
E
Evert
Nieboer
N
D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D018811:Maternal Exposure / Q000009:adverse effects*; D009139:Musculoskeletal Abnormalities / Q000139:chemically induced* / Q000453:epidemiology; D009532:Nickel / Q000009:adverse effects*; D016273:Occupational Exposure / Q000009:adverse effects; D011247:Pregnancy; D012042:Registries; D014131:Trace Elements / Q000009:adverse effects*; D055815:Young Adult
D014131:Trace Elements; D009532:Nickel