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An investigation of 5,381 white and 1,419 Negro single live births for whom the smoking status of the mother was known shows the following:1. Smoking mothers had a substantially larger proportion of infants of “low birth weight” (5 pounds, 8 ounces or less) than nonsmokers. The over-all neonatal mortality rate, however, was the same for infants of smoking and nonsmoking mothers.2. The neonatal mortality rates for single live births of “low birth weight” were substantially and significantly lower for infants of smoking than of nonsmoking mothers.3. Infants of smoking mothers weighed less than infants of nonsmoking mothers in each gestational age.4. The incidence of single live births of short gestation was only slightly and not significantly higher for smokers than for nonsmokers.5. The neonatal mortality rate of single live births of short gestation did not differ for Negro infants of smoking and nonsmoking mothers, and was only slightly lower for infants of smokers among whites.6. The neonatal mortality rate of single live births which satisfied both criteria of prematurity, i.e., with an interval of less than 37 weeks from LMP and a birth weight of 5 pounds, 8 ounces or less, were substantially and significantly lower for infants of smoking than of nonsmoking mothers.7. These findings are discussed as to possible explanations for the phenomenon of relatively more, but apparently healthier, infants of “low birth weight” among smoking than nonsmoking mothers. A causal hypothesis may be postulated in biochemical terms, but until such a mechanism can be demonstrated, it may not be unreasonable to suppose that it is not the smoking but the smoker which may offer an explanation for the observed differences.8. It is suggested that the phenomenon of smoking and its possible effect on health is very complex and it is desirable to pursue with vigor investigations aimed at elucidating the differences between the people who succumb and become habitual smokers and those who resist and never smoke.

THE INVITATION to appear at this symposium provided an opportunity to review the changes which have occurred in the relationship of the statistician and the clinician. Only a few short years ago in addressing a group similar to this one, I would have stressed the technical aspects of statistics. I would have amused myself and the audience by reciting horrible examples of false conclusions from then current literature. The situation has improved considerably over the years. Workers in clinical research acquired some knowledge in technical statistics. Often they beat the statistician to the punch. They even have learned to calculate P.Many of us are pleased with this change and happy to relinquish the position of watchdog of statistical validity. In fact, the time is not far off when the tables will be turned, and the clinician and biologist will monitor statistical investigations for biologic validity.In many mathematical and

In a cohort of 18,500 newborn infants, those who had experienced one or more convulsions were studied. Data were available for the unaffected as well as for the affected children. All families were members of a prepaid medical care program that provides comprehensive medical care.

THE CONCEPT of prematurity has evolved over the years and expanded beyond the intuitive notion of a pregnancy which terminates before term. Currently it assumes more nearly the connotation of a pregnancy which terminates before the fetus derived the benefit of full and satisfactory intrauterine development. It is, thus, not limited to pregnancies which terminate early—it implies, rather, that the fetus did not develop in utero long enough or well enough. For purposes of investigating the phenomenon of prematurity, it is therefore not sufficient to employ an index of "length of pregnancy." It is desirable to utilize also an index of "adequacy of intrauterine development."It is difficult to formulate a satisfactory objective index of adequacy of intrauterine development since the fetus can be observed and evaluated only after the pregnancy terminates. One must therefore rely primarily on extrauterine measures and yardsticks. The anthropometric measurements of weight, of length, and

The study explores the question whether the increase in low-birth-weight infants to smoking gravidas is due to the smokingor the smoker. The method was that of investigating the reproductive performance of future smokers during the periods before they acquired the smoking habit. It was found that women who subsequently became smokers had a high incidence of low-birth-weight infants also during the period before they started to smoke. It was concluded that the findings raise doubt and argue against the proposition that cigarette smoking acts as an exogenous factor which interferes with the intrauterine development of the fetus. Rather, the evidence appears to support the hypothesis that the higher incidence of low-birth-weight infants is due to the smoker, not the smoking.

This paper provides an analysis of the previous reproductive histories of all the women on the Island of Kauai, Territory of Hawaii, who had experienced at least one pregnancy. The data for the study were obtained from all women of childbearing age taken as part of a complete enumeration of the population of the island made in conjunction with a longitudinal study which is in progress. The data have been tested for all needed indices and found reliable when obtained from women who were less than 50 years of age. Consequently the analysis is based on the information obtained from this group of women. The following findings are recorded: 1.1. The results confirm other studies on the relatively high incidence of early fetal deaths. There were more than twice as many early as late fetal deaths.2.2. The factors of order of pregnancy and age of the mother have some-what different effects on the early fetal death rate, the late fetal and neonatal mortality rates, and the postneonatal death rates. The effect of order of pregnancy is stronger for the older infants, while the age of the mother exerts a greater influence on fetal mortality.3.3. The interval between the termination of one pregnancy and the beginning of the next is associated with the survival of the offspring. The early fetal, late fetal, and neonatal mortality rates are high when the interval is short. They are at a minimum when the interval is around 2 years, and increase for longer intervals. On the other hand, postneonatal and childhood mortality rates are lower when the interval between pregnancies is longer.4.4. There is a strong association between the outcome of one pregnancy and that of the immediately preceding one. When a mother suffers a loss in the form of a fetal or infant death, the chances are increased that she will sustain a subsequent loss. This association is specific for type of loss, i.e., when a woman has had an early fetal death she is more likely to have a similar accident in a subsequent pregnancy, but her chance of sustaining a late fetal loss is no greater than when the previous pregnancy resulted in a surviving infant. Similarly, if a women has sustained a previous loss through a late fetal death the likelihood of a similar accident is increased but the chance for an early fetal death in a subsequent pregnancy is not increased.5.5. These findings are discussed in terms of possible etiological and causative factors. It is suggested that the three types of losses, (1) early fetal, (2) late fetal and neonatal, and (3) postneonatal mortality, represent three distinct manifestations of reproductive wastage, and are influenced by biological and environmental factors to different degrees and in different ways. Early fetal deaths are probably influenced most by unfavorable biological factors. Environmental factors become increasingly important as age increases.6.6. The type of retrospective study described was found to be reliable and should provide a valuable method for further studies of reproductive wastage.7.7. The specific repetitive character of reproductive wastage points to the value of complete and accurate reproductive histories as a means of increasing data available for study and for providing information of immediate value in the provision of care to pregnant women.

In a prospective study, data on whether an antinauseant drug was prescribed in the first 12 weeks of pregnancy were available for 4,277 gravidas—330 fell into the meclizine-cyclizine group, 473 were prescribed “other” antinauseant drugs, and for the remainder no antinauseant drugs were prescribed.