Table 2.
Maternal cell phone use during pregnancy by cohort [% (n)]
| Categorization used in analysis | Netherlands | Denmark | Spaina | Norway | Koreaa | Total | |||
|---|---|---|---|---|---|---|---|---|---|
|
|
|
|
|
|
|||||
| None | none | 6.7 (163) | 60.8 (30,419) | 2.9 (35) | Seldom/neverb | 6.5 (1,938) | none | 0.8 (4) | 38.8 (32,564) |
| Low (reference) | 0–1 calls/day | 43.4 (1,051) | 21.9 (10,947) | 37.6 (451) | A few times a week | 38.9 (11,572) | 1–2 calls/day | 17.5 (85) | 28.7 (24,191) |
| Medium | 2–3 calls/day 4 calls or |
27.4 (662) | 12.4 (6,207) | 38.3 (459) | Daily | 50.0 (14,855) | 3–5 calls/day 6 or more |
52.0 (253) | 26.8 (22,518) |
| High | more/day | 22.5 (544) | 4.9 (2,466) | 21.3 (255) | More than an hour a day | 4.6 (1,355) | calls/day | 29.8 (145) | 5.7 (4,804) |
a
In the INMA and MOCEH cohorts, 5 and 13 women, respectively, reported using a cell phone during pregnancy but did not report frequency and therefore were excluded from frequency of calls analyses.
b
Seldom/never was the lowest call frequency category collected in the MoBa cohort.