> A 1-mg/L increase in MUFSG was associated with a 4.49-point lower IQ score (95% CI, −8.38 to −0.60) in boys,
> but there was no statistically significant association with IQ scores in girls (B = 2.40; 95% CI, −2.53 to 7.33).
> A 1-mg higher daily intake of fluoride among pregnant women was associated with a 3.66 lower IQ score (95% CI, −7.16 to −0.14) in boys and girls.
I'm not sure about the notation, but the results look pretty close to include the null hypothesis, where the change is 0.