A pooled analysis of 2 birth cohorts was conducted in France to study the association between maternal cumulative exposure to extremely low frequency magnetic fields on pregnancy outcomes.
In a previous study, Migault et al. (2018) have reported no effect of maternal exposure to extremely low frequency electromagnetic field on moderate prematurity and small for gestational age (SGA), but extreme and very premature births were not present in the studied population.
Three stages of preterm birth were defined: extreme preterm birth (< 28 completed weeks), very preterm birth (between 28 and 32 completed weeks) and moderate preterm birth (between 32 and 37 completed weeks). Small for gestational age (SGA) was defined as a birth weight below the 10th percentile of individualized French reference curves.
| Group | Description |
|---|---|
| Reference group 1 | cumulative exposure, period 1 (up to 15 weeks of gestation): < 9.6 µT-days |
| Group 2 | cumulative exposure, period 1 (up to 15 weeks of gestation): 9.6 - 14.6 µT-days |
| Group 3 | cumulative exposure, period 1 (up to 15 weeks of gestation): 14.6 - 24.8 µT-days |
| Group 4 | cumulative exposure, period 1 (up to 15 weeks of gestation): ≥ 24.8 µT-days |
| Reference group 5 | cumulative exposure, period 2 (up to 28 weeks of gestation): < 16.5 µT-days |
| Group 6 | cumulative exposure, period 2 (up to 28 weeks of gestation): 16.5 - 25.1 µT-days |
| Group 7 | cumulative exposure, period 2 (up to 28 weeks of gestation): 25.1 - 42.6 µT-days |
| Group 8 | cumulative exposure, period 2 (up to 28 weeks of gestation): ≥ 42.6 µT-days |
| Reference group 9 | cumulative exposure, period 3 (up to 32 weeks of gestation): < 18.2 µT-days |
| Group 10 | cumulative exposure, period 3 (up to 32 weeks of gestation): 18.2 - 27.6 µT-days |
| Group 11 | cumulative exposure, period 3 (up to 32 weeks of gestation): 27.6 - 46.9 µT-days |
| Group 12 | cumulative exposure, period 3 (up to 32 weeks of gestation): ≥ 46.9 µT-days |
| Reference group 13 | mean workday exposure: < 0.13 µT-days |
| Group 14 | mean workday exposure: 0.13 - 0.19 µT-days |
| Group 15 | mean workday exposure: 0.19 - 0.33 µT-days |
| Group 16 | mean workday exposure: ≥ 0.33 µT-days |
| Type | Value |
|---|---|
| Total | 19,894 |
According to the period studied, 3.2 % to 4 % of mothers were classified as highly exposed.
For prematurity, the results were heterogeneous. Increased risks of prematurity were found among low exposed mothers for the three periods (group 2: OR 1.20, CI 1.11-1.30; group 6: OR 1.19, CI 1.10-1.29; group 10: OR 1.16, CI 1.03-1.30), while no association was observed among the most exposed groups.
For SGA, no association was observed with the exception of increased risk among the low exposed mothers (group 6: OR 1.12, CI 1.03-1.22) and the most exposed mothers (group 12: OR1.25, CI 1.02-1.53).
The authors concluded that some heterogeneous associations between maternal cumulative exposure to extremely low frequency magnetic fields and prematurity and small for gestational age were observed. However, due to heterogeneity (i.e., their independence regarding the level of exposure), associations cannot be definitely explained by extremely low frequency magnetic field exposure.
This website uses cookies to provide you the best browsing experience. By continuing to use this website you accept our use of cookies.
