Tobacco is one of medicine’s greatest enemies, and its harmful effects have been noted for decades. One of the aspects that doctors warn about most is the risks that this habit poses during pregnancy for mother and child. There are many studies on this topic: “It’s an old friend,” says Gerardo Romera, head of the neonatal and pediatric intensive care unit at the University Hospital of His Majesty Monteprincipe. This week, a study published in Journal of Public Health Epidemiology shows that smoking before pregnancy, even if it’s just a cigarettealso harms the health of the newborn.
A team of researchers from China and Switzerland used data from 12 million mother-child pairs in the United States between 2016 and 2019. The authors say it is the largest sample used in such studies to date. In their study, they found that if a mother smokes before pregnancy, increases by 27% the risk of serious health problems for the newborn. If you do this at any time during pregnancy, it can be 32% higher. In this North American country, just under 10% of pregnant women smoke, and in Spain this figure doubles. The latest available data, published in 2019 by the Carlos III Institute of Health, suggests that 20% of pregnant women in our country continue this habit during pregnancy.
According to Romera, this habit can lead to babies being born smaller, underweight and premature. In the text, the authors indicate that they have seen “significant association” between maternal smoking before and during pregnancy and admission of infants to the neonatal intensive care unit. Specifically, the risk increased by 24% if the mother smoked before pregnancy and by about 30% if she smoked during pregnancy. There was also an increased risk of seizures and severe neurological dysfunction. The scientists suggest that smoking during pregnancy may “alter the structures of the fetal brain.”
Other problems associated with this habit include impaired lung function and breathing problems. In addition, the authors also found that children born to mothers who smoked had increased risk of needing assisted ventilation immediately after birth and for more than six hours. Smoking is dangerous throughout pregnancy, Romera says, but the greatest danger is in the first few weeks, when the embryo is still developing. “There is a higher abortion rate.”
The neonatologist explains that the child, just like the mother, is susceptible to these harmful effects. Tobacco contains 5300 toxic components which first reach the mother’s blood and then the baby through the placenta. One of these elements is carbon monoxide, which displaces oxygenation and “creates relative hypoxia,” Romera adds.
Problems caused by smoking are observed not only during birth or the first months of a child’s life. This is something that will last your entire life.. For the HM Hospitales doctor, these problems should be obvious. “If the toxicity of tobacco remains even after quitting, why won’t it affect the baby?”
The authors warn that the work is an observational study, so the conclusions are not entirely clear and, in the expert’s opinion, caution should be exercised when interpreting them. However, this conclusion is clear: “There is no safe period or level. smoking cigarettes shortly before or during pregnancy.
Romera agrees, adding that the only amount without risk of consumption is “zero.” The neonatologist also points out large sample size which was used: “This gives it significant statistical power. In addition, the study’s attempt to objectively demonstrate these risks stands out. “While there is no clear answer, this type of study provides more information in this regard.”
The best time to quit smoking
For the HM Hospitales doctor, the results are also a sign that pregnancy is a good time to quit smoking. “It’s better not to smoke, but if you smoke, what better time to quit than when you want to get pregnant,” he defends. Romera does not believe that the current persistence of the habit is due to a lack of information and whoever does it, does it “because they want to”. The question that worries the specialist is how dangerous it is for pregnant women to believe that a certain amount can be safe or that it is not that important. “Two cigarettes are not the same as 20, but there is always a risk.”
The specialist believes that, despite this, explanatory work must be carried out at all levels of medicine: from primary care to obstetrics. “It is the responsibility of all of us who are involved in this area.”However, he regrets that although these professional efforts are necessary, it is an individual decision that each person must make.
Romera believes that even if we had completely conclusive information on the matter, “there would still be mothers who smoke,” he laments. The neonatologist explains that much of the difficulty in making such claims completely safe is that there are other factors except for tobacco, which can affect children’s health. For example, when a premature baby has health problems throughout its life, “it is impossible to know how much is due to prematurity and how much is due to tobacco exposure.”