The modern understanding that smoking during pregnancy endangers a developing fetus is a relatively recent public health achievement. For generations, smoking was a widely accepted social practice, even for expectant mothers, with no widespread medical or public concern about the effects on the unborn child. This historical acceptance, fueled by aggressive marketing and a lack of scientific data, stands in stark contrast to the current medical consensus. The shift from a normalized habit to a recognized health hazard involved decades of scientific investigation and regulatory action.
The Era of Acceptance
The early to mid-20th century saw smoking become deeply integrated into Western culture, with the medical community raising few objections about its use by women or pregnant individuals. Tobacco companies actively encouraged this perception by targeting women with advertising campaigns beginning as early as the 1920s. Advertisements often linked cigarettes to themes of sophistication, fashion, and even weight control, as seen in the early campaign slogan “Reach for a Lucky instead of a sweet.”
The social acceptability of smoking among women increased significantly, particularly during and after World War II. The prevalence of smoking among women continued to rise, reaching a peak around the mid-1960s. During this period, there was no generalized concern or pressure for expectant mothers to quit, and it was common for women to smoke actively throughout their pregnancies. The underlying assumption was that the habit was not overtly harmful to the fetus.
Initial Scientific Inquiry
The first cracks in this wall of acceptance appeared in the late 1950s and early 1960s, following research that linked smoking to lung cancer and other diseases in the general population. Epidemiological studies began to systematically investigate the association between maternal smoking and birth outcomes. An early, consistent finding that raised suspicion was the correlation between maternal smoking and lower infant birth weight.
Researchers observed that babies born to mothers who smoked were, on average, born weighing less than those born to non-smokers, with the effect being more pronounced for heavier smokers. This association was robust, even when accounting for other potential factors. This initial focus on reduced fetal growth provided the first data-driven indication that tobacco smoke exposure was negatively impacting the development of the unborn child.
Establishing the Scientific Consensus
Correlation gave way to established causation starting in the late 1960s and through the 1970s, as more comprehensive studies solidified the evidence of specific harms. The scientific community moved beyond simply noting lower birth weight to definitively linking maternal smoking to a range of severe outcomes. This transition was marked by the inclusion of this evidence in official health reports.
Smoking during pregnancy was directly associated with an increased risk of premature birth. Maternal smoking was also found to increase the risk of fetal and neonatal deaths, including stillbirths and deaths in the first weeks of life. A serious later finding was the definitive link between maternal smoking and an elevated risk for Sudden Infant Death Syndrome (SIDS).
Regulatory and Public Health Response
The accumulating scientific evidence prompted a regulatory and public health response beginning in the mid-1960s. The first federal law requiring a health warning on cigarette packages in the United States was the Federal Cigarette Labeling and Advertising Act of 1965. This initial warning, implemented in January 1966, was relatively weak, stating only, “Caution: Cigarette Smoking May Be Hazardous to Your Health”.
A stronger response came with the Public Health Cigarette Smoking Act, signed into law in 1970, which banned cigarette advertising on American radio and television and required a more explicit warning on packages. The new label, “Warning: The Surgeon General Has Determined that Cigarette Smoking Is Dangerous to Your Health,” elevated the seriousness of the hazard. Subsequent Surgeon General’s reports throughout the 1970s and 1980s increasingly focused on the unique dangers of smoking to pregnant women and children. Public health messaging began to actively target expectant mothers, leading to a cultural shift where smoking during pregnancy transitioned from being common to being socially and medically discouraged.