Moderate Alcohol Use during Pregnancy And Decreased Infant Birth Weight RUTH E. LITTLE, ScD
Abstract: Maternal alcoholism during pregnancy may result in severe prenatal growth deficiency. In this prospective study, the relationship of moderate maternal alcohol consumption to infant birth weight is explored. Subjects were 263 paying members of a health maintenance organization who delivered single live children. Their alcohol consumption before pregnancy, and in early and late pregnancy, was estimated. In order to control for smoking, which is strongly related to both infant birth weight and maternal alcohol use, the sample was selected so that similar proportions of smokers were represented in both light and heavier drinkers. Multiple linear regression was employed. A regression equation was computed for each of the three periods in which drinking was estimated.
Independent variables entered into the equation were maternal age, height, parity, daily cigarettes, alcohol use in the period, and gestational age and sex of child. The regression of birth weight on these variables revealed a significant relationship (p c .01) with alcohol consumption in two of the periods. Ingestion of an average of one ounce of absolute alcohol daily before pregnancy was associated with an average decrease in birth weight of 91 grams; the same amount ingested in late pregnancy was associated with a decrease of 160 grams. The associations were independent of the other variables entered into the equation, and in particular, of tobacco use. (Am. J. Public Health 67:1154-
Maternal alcoholism during pregnancy may result in altered growth and morphogenesis in the newborn. In a recent series of provocative clinical reports, Jones et al., have described a pattern of malformation in the children of chronic alcoholic mothers which they term "fetal alcohol syndrome" (1-3). The syndrome is associated with severe prenatal growth deficiency and developmental delay. The effect of more moderate consumption of alcohol during pregnancy is unknown. The purpose of this paper is to report on an observed association between moderate maternal alcohol use and decreased birth weight. This suggests the possibility of a continuum of effects over the alcohol consumption spectrum, with minor alterations in growth at one end and fetal alcohol syndrome at the other extreme.
cines, and beverage consumption in three time periods. Two personal interviews were conducted: one in the fourth and one in the eighth month of gestation. In the first, data on the
Subjects and Methods Subjects in this study were obstetrical patients who sought prenatal care by the middle of their fourth month of pregnancy. All were paying members of a health maintenance organization in Seattle, Washington. As far as could be determined, no subject had any medical condition which would affect the growth of her infant. Information was obtained on smoking, use of mediAddress reprint requests to Dr. Ruth E. Little, Research Instructor, Department of Psychiatry and Behavioral Sciences, GI-80, University of Washington, Seattle, WA 98195. This paper, submitted to the Journal May 2, 1977, revised, and accepted for publication July 25, 1977, is based on a paper presented at the Annual Meeting of the Society for Epidemiologic Research, Seattle, June 1977. 1154
1156, 1977.)
six months before pregnancy and the first four months of pregnancy were obtained; these periods are termed "before" and "early" pregnancy. The fifth through eighth months ("late" pregnancy) were covered in the second interview. Alcohol use was estimated with the instrument used by Jessor (4), which measures average daily ounces of absolute alcohol ingested; this value is termed "AA score". An AA score of 1.00 is equivalent to daily consumption of two ounces of iOO-proof whiskey. Because smoking is correlated with decreased birth weight (5-7) and a strong relationship exists between alcohol and tobacco use (8), control for smoking was of prime importance in study design. To adjust for this and other relevant variables, multiple linear regression was employed, using a sample in which alcohol and tobacco use were not significantly correlated.* Plans for selecting this sample were based on estimates of non-pregnancy drinking in the population under study, which was assumed to remain constant after conception. In fact, it did not, and many problems were encountered. Sample selection is therefore described in some detail below. A total of 902 consecutive patients were approached as potential subjects, and 801 agreed to participate. The first 156 women were interviewed personally. These interviews provided the first description of drinking habits during pregnancy in any population. They revealed that alcohol use de*Technical details available on request. AJPH December 1977, Vol. 67, No. 12
ALCOHOL USE AND BIRTH WEIGHT
creased dramatically after conception; 60 per cent of the women were virtual abstainers, almost double the proportion expected in this population (9). Furthermore, most of the virtual abstainers were non-smokers. Such a large proportion on non-smoking, very light drinkers was undesirable in the sample to be used in the regression analysis. To screen out additional non-smoking, very light drinkers, the remaining potential subjects were asked by telephone about their smoking and drinking habits in the month before pregnancy.t The questions were included with inquiries about diet in order to camouflage their importance. Women were interviewed personally only if they drank and/ or smoked in this month. Alcohol use after conception dropped so uniformly that the probability of heavy drinking during gestation by a woman who had previously abstained was calculated to be nearly zero. AA scores and smoking status were not significantly different for the group subjected to telephone screening than for those interviewed without prior contact. In all, 73 of the 801 women contacted reported alcohol consumption estimated by an AA score of at least 1.00 before or in early pregnancy. Of this group, 66 delivered single live children at the participating hospital.** Each of these mothers was matched on smoking status (smoker/nonsmoker) with three additional subjects as they became available: one subject who consumed at most .10 ounces of alcohol in both periods, and two subjects whose alcohol consumption was intermediate (.10 < AA score < 1.00). These women made up the sample of 264 used in the initial regression analysis. The careful selection of subjects described here effectively eliminated the correlation of smoking and alcohol use. The Pearson correlation between number of daily cigarettes and AA score in any period is less than .05 in this sample. Thus the relative contributions of the two variables may be assessed independently. Separate regression equations were computed for each of the three periods in which drinking was measured. Initially, birth weight was regressed on seven independent variables; the primary variable of AA score in the period, and the secondary variables of maternal age, height, parity, number of cigarettes smoked per day, and gestational age and sex of child. All variables were entered simultaneously into the equation. Any secondary variable having a regression coefficient significant above the .10 level by the F-test was deleted. One outlier was also excluded, bringing the number in the sample to 263. The equations were then re-computed.
Results The demographic characteristics of the sample and their drinking and smoking habits are shown in Table 1. The AA
tThis period was chosen because it was the most recent month before conception and therefore should have been the most clearly remembered of the "before" pregnancy period. **One of the 73 women failed to deliver a live child, three had multiple births, one developed gestational diabetes, and two gave birth in other cities. AJPH December 1977, Vol. 67, No. 12
TABLE 1 Demographic and Fertility Data and Alcohol Consumption in Three Periods in a Sample of 263 Pregnant Women.
Mean height (inches) Mean age (years) Mean parity (live births) Per cent white Per cent smokers Mean AA score (in ounces of absolute alcohol) Before pregnancy Early pregnancy Late pregnancy
64.8 26.8 1.0 94% 39% .64 .24 .27
scores before pregnancy ranged between 0 and 6.25; the range for the scores in early and late pregnancy was from 0 to 2.03 and 2.47, respectively. Only four subjects gave evidence of alcohol abuse by any accepted definition. The first regression equations to be computed indicated that maternal age was not significantly related to birth weight in any of the three periods (p > .20 by the F-test in all cases). This variable was therefore deleted and the equations recomputed. The results are shown in Table 2. The equations explain roughly 30 per cent of the variance in birth weight. Inspection of the coefficient of the AA score before pregnancy shows that a score of 1.0 (an average of one ounce of absolute alcohol daily) is associated with a decrease in birth weight of 90.8 grams; the coefficients in the other periods are similarly interpreted. By traditional standards, the coefficients of the alcohol use scores before pregnancy and in late pregnancy are highly significant (p c .01), but the coefficient of alcohol use in early pregnancy is not. The lack of significance for alcohol use in early pregnancy may be due in part to the small number of women with high AA scores in this period. Alcohol use fell so low that the regression analysis may have been ineffective. Only 13 women had AA scores of more than 1.00 during early pregnancy, in contrast to 64 women before pregnancy and 20 in late pregnancy. Seven infants born to women in the sample weighed under 2,500 grams. Regardless of the mother's alcohol consumption, all were examined for fetal alcohol syndrome by a physician trained to recognize it. No cases of the syndrome were found.
Discussion and Summary The data presented here indicate that maternal alcohol use before pregnancy and in late pregnancy is significantly related to infant birth weight. In this sample, daily consumption of one ounce of absolute alcohol before pregnancy is associated with a decrease in birth weight of 91 grams. One ounce consumed in late pregnancy is associated with a decrease in birth weight of 160 grams. Evaluation of these results must take account of the high correlation between alcohol and tobacco use noted in this and other populations. Smoking during pregnancy has been associated with low birth weight and increased risk of perinatal mortality (5-7). Yet these reports have failed to 1155
LITTLE
TABLE 2-Regression of Birth Weight on Maternal Alcohol Use In Three Periods and Other Related Variables (N Before Pregnancy
Variables
AA score Mother's height Average daily cigarettes during pregnancy Parity Sex of childc Gestational age Constant Total variance explained Significance of the equation * = Less than .01 a
Significanceb
Coefficient
263).1
Late Pregnancy
Coefficient
Significanceb
-90.8 17.9
* .05
-95.2 16.0
.19 .08
-159.7 16.7
.01 .06
-10.7 79.6 -83.4 145.3 -3306.5
* * .08 * *
-10.7 83.5 -93.7 145.3 -3208.6
* .06 *
-10.5 95.2 -102.7 140.7 -3044.1
* .04
.32
Two women could not be interviewed a second time, so N
b Significance figures determined by the F-test. c Sex is coded 1 for males and 2 for females.
=
.29
.30
261 in the late pregnancy period.
control for alcohol use. Use of regression analysis with a carefully selected sample in this study indicates that the association of maternal drinking and infant birth weight observed here is independent of maternal smoking, as well as mother's age, height, parity, and the gestational age and sex of the child. The significance of the variables shown in Table 2 and the proportion of variance they explain is generally in accord with the results of Pettersson and Melander who attempted to predict birth weight by multiple regression. However, they found alcohol use was not significant. Perhaps this was because they used only two categories for this variable: some drinking and no drinking. Imprecision of measurement may thus have obscured a relation to birth weight. (10) Using more careful estimates, Kaminski et al. reported a significant relationship between alcohol use during pregnancy and birth weight. A linear regression was employed, and the authors note that the differences in birth weight by alcohol consumption were independent of tobacco use. (11) Although the relationship between maternal alcohol use and infant birth weight reported here is significant, inferences from this study must be drawn with care. The sample is taken from a distinctive population of basically white middle class women who were members of a health maintenance organization. Single live births only were included. Other variables such as maternal weight and pregnancy weight gain may have also influenced infant birth weight. The number in the sample is small, and the robust results based on large numbers and traditional techniques are missing here. Finally, birth weight is not equivalent to fetal health. "Nice fat babies" are not necessarily the healthiest. Nor are the factors involved in lowered birth weight always those associated with teratogenic outcomes and perinatal mortality. However, reduction in birth weight with moderate maternal alcohol use may represent minimal damage on a spec-
1156
Early Pregnancy Coefficient Significanceb
=
trum of growth retardation. The present study merely opens the door to this major question.
REFERENCES 1. Jones, K., Smith, D., Ulleland, C. and Streissguth, A. Pattern of malformation in offspring of chronic alcoholic mothers. Lancet 1:1267-1271, 1973. 2. Jones, K. and Smith, D. Recognition of the fetal alcohol syndrome in early infancy. Lancet 2:999-1001, 1973. 3. Jones, K., Smith, D., Streissguth, A. and Myrianthopoulos, N. Outcome in offspring of chronic alcoholic women. Lancet 1:1076-1078, 1974. 4. Jessor, R., Graves, T., Hanson, R. and Jessor, S. Society, Personality, and Deviant Behavior. New York: Holt Rinehart and Winston, 1968. 5. Andrews, J. and McGarry, J. M. A community study of smoking in pregnancy. J. Obstet. Gynecol. British Commonwealth 79:1057-1973, 1972. 6. Fabia, J. Cigarettes pendant la grossesse, poids de naissance, et mortalite perinatale. Can. Med. Assn. J. 109:1104-1108, 1973. 7. Meyer, M. B., Tonascia, J. A. and Buck, C. The interrelationship of maternal smoking and increased perinatal mortality with other risk factors. Amer. J. Epid. 100:443-452, 1975. 8. Cahalan, D., Cisin, I. and Crossley, H. American Drinking Practices. New Brunswick, NJ: Rutgers Center for Alcohol Studies, 1969. 9. Little, R., Schultz, F. and Mandell, W. Drinking during pregnancy. J. Stud. Alc. 37:375-379, 1976. 10. Pettersson, F. and Melander, S. Prediction of birth weight: Results of a multiple regression analysis. Upsala J. Med. Sci. 80:135-140, 1975. 11. Kaminski, M., Rumeau-Roquette, C. and Schwartz, D. Consommation d'alcool chez les femmes enceintes et issue de la grossesse. Rev. Epidem, et Sante Pubi. 24:27-40, 1976.
ACKNOWLEDGMENTS
I am especially grateful to Dr. Kenneth L. Jones, who encouraged me in the early stages of this project, and to Dr. Ann P. Streiss-
guth, who also provided support and facilities. Drs. Jones, David Smith, and James Hansen examined the low birth weight babies. This work was supported in part by a grant from the National Institute on Alcohol Abuse and Alcoholism, USDHEW, Grant Number AA 01274-01.
AJPH December 1977, Vol. 67, No. 12
Abstract: Maternal alcoholism during pregnancy may result in severe prenatal growth deficiency. In this prospective study, the relationship of moderate maternal alcohol consumption to infant birth weight is explored. Subjects were 263 paying members of a health maintenance organization who delivered single live children. Their alcohol consumption before pregnancy, and in early and late pregnancy, was estimated. In order to control for smoking, which is strongly related to both infant birth weight and maternal alcohol use, the sample was selected so that similar proportions of smokers were represented in both light and heavier drinkers. Multiple linear regression was employed. A regression equation was computed for each of the three periods in which drinking was estimated.
Independent variables entered into the equation were maternal age, height, parity, daily cigarettes, alcohol use in the period, and gestational age and sex of child. The regression of birth weight on these variables revealed a significant relationship (p c .01) with alcohol consumption in two of the periods. Ingestion of an average of one ounce of absolute alcohol daily before pregnancy was associated with an average decrease in birth weight of 91 grams; the same amount ingested in late pregnancy was associated with a decrease of 160 grams. The associations were independent of the other variables entered into the equation, and in particular, of tobacco use. (Am. J. Public Health 67:1154-
Maternal alcoholism during pregnancy may result in altered growth and morphogenesis in the newborn. In a recent series of provocative clinical reports, Jones et al., have described a pattern of malformation in the children of chronic alcoholic mothers which they term "fetal alcohol syndrome" (1-3). The syndrome is associated with severe prenatal growth deficiency and developmental delay. The effect of more moderate consumption of alcohol during pregnancy is unknown. The purpose of this paper is to report on an observed association between moderate maternal alcohol use and decreased birth weight. This suggests the possibility of a continuum of effects over the alcohol consumption spectrum, with minor alterations in growth at one end and fetal alcohol syndrome at the other extreme.
cines, and beverage consumption in three time periods. Two personal interviews were conducted: one in the fourth and one in the eighth month of gestation. In the first, data on the
Subjects and Methods Subjects in this study were obstetrical patients who sought prenatal care by the middle of their fourth month of pregnancy. All were paying members of a health maintenance organization in Seattle, Washington. As far as could be determined, no subject had any medical condition which would affect the growth of her infant. Information was obtained on smoking, use of mediAddress reprint requests to Dr. Ruth E. Little, Research Instructor, Department of Psychiatry and Behavioral Sciences, GI-80, University of Washington, Seattle, WA 98195. This paper, submitted to the Journal May 2, 1977, revised, and accepted for publication July 25, 1977, is based on a paper presented at the Annual Meeting of the Society for Epidemiologic Research, Seattle, June 1977. 1154
1156, 1977.)
six months before pregnancy and the first four months of pregnancy were obtained; these periods are termed "before" and "early" pregnancy. The fifth through eighth months ("late" pregnancy) were covered in the second interview. Alcohol use was estimated with the instrument used by Jessor (4), which measures average daily ounces of absolute alcohol ingested; this value is termed "AA score". An AA score of 1.00 is equivalent to daily consumption of two ounces of iOO-proof whiskey. Because smoking is correlated with decreased birth weight (5-7) and a strong relationship exists between alcohol and tobacco use (8), control for smoking was of prime importance in study design. To adjust for this and other relevant variables, multiple linear regression was employed, using a sample in which alcohol and tobacco use were not significantly correlated.* Plans for selecting this sample were based on estimates of non-pregnancy drinking in the population under study, which was assumed to remain constant after conception. In fact, it did not, and many problems were encountered. Sample selection is therefore described in some detail below. A total of 902 consecutive patients were approached as potential subjects, and 801 agreed to participate. The first 156 women were interviewed personally. These interviews provided the first description of drinking habits during pregnancy in any population. They revealed that alcohol use de*Technical details available on request. AJPH December 1977, Vol. 67, No. 12
ALCOHOL USE AND BIRTH WEIGHT
creased dramatically after conception; 60 per cent of the women were virtual abstainers, almost double the proportion expected in this population (9). Furthermore, most of the virtual abstainers were non-smokers. Such a large proportion on non-smoking, very light drinkers was undesirable in the sample to be used in the regression analysis. To screen out additional non-smoking, very light drinkers, the remaining potential subjects were asked by telephone about their smoking and drinking habits in the month before pregnancy.t The questions were included with inquiries about diet in order to camouflage their importance. Women were interviewed personally only if they drank and/ or smoked in this month. Alcohol use after conception dropped so uniformly that the probability of heavy drinking during gestation by a woman who had previously abstained was calculated to be nearly zero. AA scores and smoking status were not significantly different for the group subjected to telephone screening than for those interviewed without prior contact. In all, 73 of the 801 women contacted reported alcohol consumption estimated by an AA score of at least 1.00 before or in early pregnancy. Of this group, 66 delivered single live children at the participating hospital.** Each of these mothers was matched on smoking status (smoker/nonsmoker) with three additional subjects as they became available: one subject who consumed at most .10 ounces of alcohol in both periods, and two subjects whose alcohol consumption was intermediate (.10 < AA score < 1.00). These women made up the sample of 264 used in the initial regression analysis. The careful selection of subjects described here effectively eliminated the correlation of smoking and alcohol use. The Pearson correlation between number of daily cigarettes and AA score in any period is less than .05 in this sample. Thus the relative contributions of the two variables may be assessed independently. Separate regression equations were computed for each of the three periods in which drinking was measured. Initially, birth weight was regressed on seven independent variables; the primary variable of AA score in the period, and the secondary variables of maternal age, height, parity, number of cigarettes smoked per day, and gestational age and sex of child. All variables were entered simultaneously into the equation. Any secondary variable having a regression coefficient significant above the .10 level by the F-test was deleted. One outlier was also excluded, bringing the number in the sample to 263. The equations were then re-computed.
Results The demographic characteristics of the sample and their drinking and smoking habits are shown in Table 1. The AA
tThis period was chosen because it was the most recent month before conception and therefore should have been the most clearly remembered of the "before" pregnancy period. **One of the 73 women failed to deliver a live child, three had multiple births, one developed gestational diabetes, and two gave birth in other cities. AJPH December 1977, Vol. 67, No. 12
TABLE 1 Demographic and Fertility Data and Alcohol Consumption in Three Periods in a Sample of 263 Pregnant Women.
Mean height (inches) Mean age (years) Mean parity (live births) Per cent white Per cent smokers Mean AA score (in ounces of absolute alcohol) Before pregnancy Early pregnancy Late pregnancy
64.8 26.8 1.0 94% 39% .64 .24 .27
scores before pregnancy ranged between 0 and 6.25; the range for the scores in early and late pregnancy was from 0 to 2.03 and 2.47, respectively. Only four subjects gave evidence of alcohol abuse by any accepted definition. The first regression equations to be computed indicated that maternal age was not significantly related to birth weight in any of the three periods (p > .20 by the F-test in all cases). This variable was therefore deleted and the equations recomputed. The results are shown in Table 2. The equations explain roughly 30 per cent of the variance in birth weight. Inspection of the coefficient of the AA score before pregnancy shows that a score of 1.0 (an average of one ounce of absolute alcohol daily) is associated with a decrease in birth weight of 90.8 grams; the coefficients in the other periods are similarly interpreted. By traditional standards, the coefficients of the alcohol use scores before pregnancy and in late pregnancy are highly significant (p c .01), but the coefficient of alcohol use in early pregnancy is not. The lack of significance for alcohol use in early pregnancy may be due in part to the small number of women with high AA scores in this period. Alcohol use fell so low that the regression analysis may have been ineffective. Only 13 women had AA scores of more than 1.00 during early pregnancy, in contrast to 64 women before pregnancy and 20 in late pregnancy. Seven infants born to women in the sample weighed under 2,500 grams. Regardless of the mother's alcohol consumption, all were examined for fetal alcohol syndrome by a physician trained to recognize it. No cases of the syndrome were found.
Discussion and Summary The data presented here indicate that maternal alcohol use before pregnancy and in late pregnancy is significantly related to infant birth weight. In this sample, daily consumption of one ounce of absolute alcohol before pregnancy is associated with a decrease in birth weight of 91 grams. One ounce consumed in late pregnancy is associated with a decrease in birth weight of 160 grams. Evaluation of these results must take account of the high correlation between alcohol and tobacco use noted in this and other populations. Smoking during pregnancy has been associated with low birth weight and increased risk of perinatal mortality (5-7). Yet these reports have failed to 1155
LITTLE
TABLE 2-Regression of Birth Weight on Maternal Alcohol Use In Three Periods and Other Related Variables (N Before Pregnancy
Variables
AA score Mother's height Average daily cigarettes during pregnancy Parity Sex of childc Gestational age Constant Total variance explained Significance of the equation * = Less than .01 a
Significanceb
Coefficient
263).1
Late Pregnancy
Coefficient
Significanceb
-90.8 17.9
* .05
-95.2 16.0
.19 .08
-159.7 16.7
.01 .06
-10.7 79.6 -83.4 145.3 -3306.5
* * .08 * *
-10.7 83.5 -93.7 145.3 -3208.6
* .06 *
-10.5 95.2 -102.7 140.7 -3044.1
* .04
.32
Two women could not be interviewed a second time, so N
b Significance figures determined by the F-test. c Sex is coded 1 for males and 2 for females.
=
.29
.30
261 in the late pregnancy period.
control for alcohol use. Use of regression analysis with a carefully selected sample in this study indicates that the association of maternal drinking and infant birth weight observed here is independent of maternal smoking, as well as mother's age, height, parity, and the gestational age and sex of the child. The significance of the variables shown in Table 2 and the proportion of variance they explain is generally in accord with the results of Pettersson and Melander who attempted to predict birth weight by multiple regression. However, they found alcohol use was not significant. Perhaps this was because they used only two categories for this variable: some drinking and no drinking. Imprecision of measurement may thus have obscured a relation to birth weight. (10) Using more careful estimates, Kaminski et al. reported a significant relationship between alcohol use during pregnancy and birth weight. A linear regression was employed, and the authors note that the differences in birth weight by alcohol consumption were independent of tobacco use. (11) Although the relationship between maternal alcohol use and infant birth weight reported here is significant, inferences from this study must be drawn with care. The sample is taken from a distinctive population of basically white middle class women who were members of a health maintenance organization. Single live births only were included. Other variables such as maternal weight and pregnancy weight gain may have also influenced infant birth weight. The number in the sample is small, and the robust results based on large numbers and traditional techniques are missing here. Finally, birth weight is not equivalent to fetal health. "Nice fat babies" are not necessarily the healthiest. Nor are the factors involved in lowered birth weight always those associated with teratogenic outcomes and perinatal mortality. However, reduction in birth weight with moderate maternal alcohol use may represent minimal damage on a spec-
1156
Early Pregnancy Coefficient Significanceb
=
trum of growth retardation. The present study merely opens the door to this major question.
REFERENCES 1. Jones, K., Smith, D., Ulleland, C. and Streissguth, A. Pattern of malformation in offspring of chronic alcoholic mothers. Lancet 1:1267-1271, 1973. 2. Jones, K. and Smith, D. Recognition of the fetal alcohol syndrome in early infancy. Lancet 2:999-1001, 1973. 3. Jones, K., Smith, D., Streissguth, A. and Myrianthopoulos, N. Outcome in offspring of chronic alcoholic women. Lancet 1:1076-1078, 1974. 4. Jessor, R., Graves, T., Hanson, R. and Jessor, S. Society, Personality, and Deviant Behavior. New York: Holt Rinehart and Winston, 1968. 5. Andrews, J. and McGarry, J. M. A community study of smoking in pregnancy. J. Obstet. Gynecol. British Commonwealth 79:1057-1973, 1972. 6. Fabia, J. Cigarettes pendant la grossesse, poids de naissance, et mortalite perinatale. Can. Med. Assn. J. 109:1104-1108, 1973. 7. Meyer, M. B., Tonascia, J. A. and Buck, C. The interrelationship of maternal smoking and increased perinatal mortality with other risk factors. Amer. J. Epid. 100:443-452, 1975. 8. Cahalan, D., Cisin, I. and Crossley, H. American Drinking Practices. New Brunswick, NJ: Rutgers Center for Alcohol Studies, 1969. 9. Little, R., Schultz, F. and Mandell, W. Drinking during pregnancy. J. Stud. Alc. 37:375-379, 1976. 10. Pettersson, F. and Melander, S. Prediction of birth weight: Results of a multiple regression analysis. Upsala J. Med. Sci. 80:135-140, 1975. 11. Kaminski, M., Rumeau-Roquette, C. and Schwartz, D. Consommation d'alcool chez les femmes enceintes et issue de la grossesse. Rev. Epidem, et Sante Pubi. 24:27-40, 1976.
ACKNOWLEDGMENTS
I am especially grateful to Dr. Kenneth L. Jones, who encouraged me in the early stages of this project, and to Dr. Ann P. Streiss-
guth, who also provided support and facilities. Drs. Jones, David Smith, and James Hansen examined the low birth weight babies. This work was supported in part by a grant from the National Institute on Alcohol Abuse and Alcoholism, USDHEW, Grant Number AA 01274-01.
AJPH December 1977, Vol. 67, No. 12
