Effect of maternal smoking on human placental development
Creators: name: University Of California Office Of The President
Publisher: name: University of California Office of the President
publisherIdentifier: https://ror.org/00dmfq477
publisherIdentifierScheme: ROR
Year: 2024

description: Maternal cigarette smoking significantly increases the risk of serious pregnancy complications. Estimates suggest that each year tobacco use is responsible for 19,000 to 141,000 abortions, 32,000 to 61,000 low birth weight infants, 14,000 to 26,000 infants who require admission to neonatal intensive care units, and 1,900 to 4,800 infant deaths. Thus, it is not surprising that maternal cigarette smoking is unequivocally the largest and most important known, modifiable risk factor for low birth weight and infant death. 
 
 
 
 
 
 In spite of the severe negative consequences of maternal smoking on pregnancy outcome, studies suggest that approximately 20-30% of pregnant women in this country smoke. Results of a recent population-based epidemiological study conducted in California highlight the problem locally. Prevalence of prenatal tobacco use was 9% in the general population, and 29% among mothers who did not receive prenatal care. It is important to note that in this study cigarette smoking was self-reported, i.e. not verified by biochemical testing. Thus, the actual rates of prenatal smoking are likely to be far greater.
 
 
 
 
 
 Currently, little is known about how maternal tobacco use is linked to a dramatic increase in serious pregnancy complications. We are testing the theory that smoking harms the placenta. The placenta is a transient organ that exists only during pregnancy. Its short life span belies its unique functions which are vital to human development before birth. For example, pregnancy begins when placental cells attach the embryo to the mother's uterus. Once pregnancy is established, a child must develop in the uterus for many months before its organ systems can function on their own. During this time the placenta carries out, for the child, the roles played by many important organs including the heart, lungs, digestive system and kidneys. Thus, throughout this critical period toxic substances that harm the placenta likewise harm the developing child. Results of experiments we published during the previous grant period showed that the placenta is vulnerable to the toxic effects of maternal tobacco use. Smoking interferes with the way placental cells attach to the uterus, and subsequently, the way they function. Our findings suggest that the problems are primarily due to the negative effects of maternal smoking on placental growth, the focus of our current application. 
 
 
 
 
 
 We envision that the results of our study could be used in cessation studies to help women quit smoking during pregnancy. Research suggests that pregnancy is an ideal time to intervene, since many women reduce or stop cigarette consumption on learning they are pregnant. However, the effectiveness of cessation programs in this population is greatly enhanced when they use materials that are specific to pregnant women. A simple explanation of how smoking harms a child before birth, one possible outcome of our work, could be an important part of these specially designed materials. It is likely that a subset of mothers who smoke during pregnancy will be more likely to quit if they better understand the added risk their infants incur as a result of their cigarette use. In addition, if the mother is able to stop smoking permanently, her own health will greatly benefit.