Mean difference (95% CI) in birth measurements of children born to smoking mothers, comparing those where the child's grandmother had smoked with those who had not
| MGM+M+ vs MGM−M+ | PGM+M+ vs PGM−M+ | |||
|---|---|---|---|---|
| Unadjusted | Adjusted* | Unadjusted | Adjusted* | |
| Total IQ | ||||
| Boys | −3.87 | −2.45 | −4.00 | −2.90 |
| 95% CI | (−6.34 to −1.40) | (−4.96 to +0.07) | (−6.92 to −1.08) | (−5.72 to −0.08) |
| p Value | 0.002 | 0.057 | 0.007 | 0.044 |
| Number | 694 | 612 | 507 | 482 |
| Girls | −2.50 | −0.40 | −3.03 | −1.36 |
| 95% CI | (−4.90 to −0.11) | (−2.85 to +2.05) | (−5.78 to −0.28) | (−4.07 to +1.36) |
| p Value | 0.041 | 0.749 | 0.031 | 0.327 |
| Number | 617 | 551 | 456 | 436 |
| Performance IQ | ||||
| Boys | −2.64 | −1.48 | −2.44 | −1.40 |
| 95% CI | (−5.20 to −0.08) | (−4.20 to +1.24) | (−5.40 to +0.50) | (−4.39 to +1.60) |
| p Value | 0.043 | 0.287 | 0.104 | 0.360 |
| Number | 698 | 616 | 510 | 485 |
| Girls | −2.46 | −0.50 | −3.03 | −1.74 |
| 95% CI | (−5.01 to +0.09) | (−3.19 to +2.19) | (−5.88 to −0.18) | (−4.69 to +1.20) |
| p Value | 0.059 | 0.716 | 0.037 | 0.245 |
| N | 619 | 552 | 457 | 436 |
| Verbal IQ | ||||
| Boys | −3.75 | −2.40 | −4.73 | −3.65 |
| 95% CI | (−6.30 to −1.21) | (−5.00 to +1.20) | (−7.81 to −1.66) | (−6.60 to −0.70) |
| p Value | 0.004 | 0.070 | 0.003 | 0.015 |
| Number | 697 | 615 | 509 | 484 |
| Girls | −1.98 | −0.15 | −2.48 | −0.81 |
| 95% CI | (−4.37 to +0.42) | (−2.60 to +2.30) | (−5.28 to +0.32) | (−3.54 to +1.92) |
| p Value | 0.106 | 0.906 | 0.082 | 0.561 |
| Number | 617 | 551 | 456 | 436 |
Values in italics indicate a significance of p<0.05. *Adjusted for maternal education, parity, partner smoked in pregnancy, gestational length at birth of study child and the amount the mother smoked.
M, mother; MGM, maternal grandmother; PGM, paternal grandmother.