Smoking & Pregnancy
Common Risks and Conditions
Every year in the United States, more than four million infants are born low birth weight or small-for-gestational age. The problem of infants being born this way is critical. It is not enough to declare that infants who are born LBW or SGA are problems that can be solved through various programs or with the present state of knowledge. A clearer comprehension of the reasons for the existence of this problem has to become a scientific priority.
Although the U.S. has some of the most advanced medical technologies and equipment available in the world, the country’s infant mortality rate remains a critical issue. There are several factors, such as racial and ethnic disparities, late prenatal care after six month of pregnancy, and poverty that may contribute to this increased infant mortality rate. However, one of the most important and correctable is smoking during pregnancy.
Risks of Smoking During Pregnancy
Smoking during pregnancy has been related to 20% to 30% of LBW infant births and 10% of fetal deaths. Cigarette smoking is considered the single most important and modifiable risk factor for improving these excessively high LBW and infant death rates. Not only does smoking harm the health of the pregnant women, but cigarette smoking has also been shown to harm the fetus, especially in regards to retarding fetal growth. When a pregnant woman smokes, the infant’s birth weight will likely be reduced by 150 to 320 grams (5.3 to 11.4 ounces).
Even after controlling for other factors, women who smoke during pregnancy are twice as likely to give birth to low birth weight infants when compared to women who do not smoke. Smoking during pregnancy may also be associated with preterm birth, possibly accounting for up to 14% of premature deliveries. While this data is alarming, research does indicate that, since most fetal growth takes place during the last trimester, quitting smoking at any point during pregnancy can widely reduce the adverse effects of smoking on low birth weight.
Conditions Associated with Smoking During Pregnancy
Many severe conditions are associated with low birth weight and preterm births. These range from things such as mental retardation and cerebral palsy to respiratory syndrome, asthma, deafness and blindness. Out of the many health conditions that are associated with low birth weight infants who survive birth, the most disabling of those mentioned above is cerebral palsy. Infants who are born preterm with very low birth weight have been found to be 30% more likely to develop cerebral palsy than infants born at a normal birth weights.
Cerebral palsy, the result of prematurity, is defined as the inability to control gross and fine motor movement, and is usually accompanied by cognitive impairment. Poor feeding and maternal-infant communication are expressed as early signs of this disorder. Feeding problems, another possible early sign of cerebral palsy, are seen as a sign that the infants might not be able to express themselves properly, thereby facing language difficulties later in life. Early detection of this feeding problem could facilitate an alternative means of communication, vital to maintaining the infant’s cognitive development.
Seizures in the low birth weight or preterm infant are another symptom that has adverse effects on motor skills and development and may be due, in part, to cerebral palsy. Visual impairments, common in preterm infants, have also been linked to delayed motor skill development. Understanding the history of cerebral palsy and other problems associated with low birth weight and preterm birth is critical for proper prognosis for life expectancy and proper intervention in such growth and development issues as walking, talking and hand functioning. Studies have shown that pregnant mothers have some knowledge of the maternal risk of smoking while pregnant, but are lacking in knowledge and understanding about fetal risk which appears to be the greatest motivator to quit smoking. Teaching these mothers about the possibility of their infants being born with cerebral palsy, other birth defects, and the dangers of being born LBW may help motivate them to cease smoking.
It is recommended that all pregnant mothers be screened for tobacco use using structured multiple-choice questions and brief counseling done using the 5 A model with all pregnant smokers. It is important to note that, with 50% of infant mortality in the US is attributed to social and personal health behaviors, only 5% of healthcare resources are directed at improving the manner in which social and behavioral risk factors are addressed with pregnant women. Therefore, it is recommended that more resources are directed in improving social and behavioral risk factor for pregnant smokers.