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Mean Birth Weight (g) in Relation to Alcohol and Smoking Status1
.
Alcohol Drinks/day
Nonsmokers
Smokers (Packs Per Day)
(22,485)
(9,119)
½ pack
1 pack
1. 5 pk
0
3,468
±
534 (S.D.)
3,330 ±
548 3,256 ±
533 3,274 ±
519
<1
3,500 ±
527
3,386 ±
522 3,276 ±
532 3,255 ±
548
1-2
3,452 ±
582
3,253 ±
564 3,115 ±
515 3,143 ±
539
>3
3,138 ±
512
3,085 ±
626 3,407
±
537
3,099 ±
543
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The raw data suggests there is no meaningful difference between the crude mean birth weight infants of nonsmokers who drank zero drinks per day compared to <1 drink per day or 1-2 drinks per day.
For three or more drinks, the birth weight trended down significantly
even in the nonsmokers.
The
authors contend that their multiple regression analysis removes the effect of
smoking and shows there is a significant reduction in birth weight for all levels
of alcohol intake, even in nonsmokers. This may represent an overestimation of the
reliability of multiple regression analysis. For the large group of
nonsmokers in this study (22,485 pregnancies), there was no significant difference in crude mean birth weights at
low levels of alcohol intake.
(The
additional factor of the tendency of individuals to underreport alcohol intake
is difficult to address and correct for as well.)
1.
Mills JL, Graubard BI, Harley
EE, et al. Maternal alcohol consumption and birth weight: How much drinking
during pregnancy is safe? JAMA 1984:252:1875-1879.
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