Maternal cell phone use in early pregnancy and child’s language, communication and motor skills at 3 and 5 years: the Norwegian mother and child cohort study (MoBa)

Table 4 Associations between maternal cell phone use in early pregnancy and child’s motor skills in the lowest tertile at 3 and 5 years

	Risk for motor skills score in the lowest tertile
	At 3 years			At 5 years
	N total/N with low skills (%)	OR	95% CI	N total/N with low skills (%)	OR	95% CI
Maternal cell phone use in early pregnancy
Crude model
No use	4428/1541 (34.8%)	Ref.		1177/241 (20.5%)	Ref.
Any use	40,961/13,193 (32.2%)	0.89	0.83, 0.95	16,133/3685(22.8%)	1.15	0.99, 1.33
Low use	17,690/5945 (33.6%)	0.95	0.88, 1.02	6817/1562 (22.9%)	1.15	0.99, 1.34
Medium use	21,292/6669 (31.3%)	0.85	0.80, 0.91	8527/1936 (22.7%)	1.14	0.98, 1.33
High use	1979/579 (29.3%)	0.77	0.69, 0.87	789/187 (23.7%)	1.21	0.97, 1.50
p- for trend		*<0.001*			0.247
Adjusted model 1
No use	4428/1541 (34.8%)	Ref.		1177/241 (20.5%)	Ref.
Any use	40,961/13,193 (32.2%)	0.82	0.76, 0.87	16,133/3685 (22.8%)	1.02	0.88, 1.19
Low use	17,690/5945 (33.6%)	0.88	0.82, 0.94	6817/1562 (22.9%)	1.07	0.91, 1.24
Medium use	21,292/6669 (31.3%)	0.74	0.69, 0.80	8527/1936 (22.7%)	0.98	0.83, 1.14
High use	1979/579 (29.3%)	0.64	0.57, 0.72	789/187 (23.7%)	1.00	0.81, 1.25
p- for trend		*<0.001*			0.152
Adjusted model 2
No use	375/132 (35.2%)	Ref.		311/74 (23.8%)	Ref.
Any use	10,510/3544 (33.7%)	0.93	0.75, 1.16	8642/2123 (24.6%)	1.11	0.85, 1.46
Low use	3688/1323 (35.9%)	1.01	0.81, 1.27	3010/783 (26.0%)	1.17	0.89, 1.55
Medium use	6220/2040 (32.8%)	0.89	0.71, 1.11	5131/1214 (23.4%)	1.06	0.81, 1.40
High use	602/181 (30.1%)	0.79	0.60, 1.05	501/126 (24.2%)	1.20	0.85, 1.67
p- for trend		*0.001*			0.552

Bold fonts indicate statistical significant results, that are either confidence intervals that do not include 1 or p-for trend<0.05
N (%) represent the number (and percentages) of children with low motor skills (score in the lowest tertile at 3 years and score in the lowest tertile at 5 years) in each category of cell phone use. Total number of included mother-child pairs at 3 years are: n = 45,389 in crude and adjusted model 1and n = 10,885 in adjusted model 2. Total number of included mother-child pairs at 5 years are: n = 17,310 in crude and adjusted model 1and n = 8953 in adjusted model 2
Adjusted model 1 includes parity, maternal age and education and year of delivery
Adjusted model 2 includes the variables of adjusted model 1 and maternal extrovert personality score in tertiles (low/average/high)

ISSN: 1471-2458