Birth defects and drug use
Birth defects, also known as congenital disabilities, are physical abnormalities present at birth that can arise during fetal development. One significant factor contributing to these defects is drug use during pregnancy, where certain substances, known as teratogens, can interfere with normal organ formation, particularly during the critical embryonic period (weeks two to eight of pregnancy). Various drugs, including over-the-counter medications, prescription drugs, and illicit substances, have been identified as teratogenic, with common examples being tobacco, alcohol, marijuana, and opioids.
Smoking is linked to heart defects and growth issues, while alcohol can lead to fetal alcohol spectrum disorder, characterized by cognitive and physical challenges. Marijuana's effects remain less clearly defined, but ongoing research is examining its potential impact on prenatal development, especially as its usage increases among pregnant women. Opioids, such as heroin, can result in infants being born addicted and facing learning disabilities.
Given the complexities of drug interactions and the unique challenges of treating pregnant women with substance use issues, healthcare providers must carefully consider the implications of drug prescriptions. Treatment options, like methadone and Suboxone for opioid dependence, are evolving, with studies suggesting potential safety and efficacy for these medications during pregnancy. Understanding the risks of drug use during pregnancy is crucial for ensuring the health and well-being of both mothers and their children.
Subject Terms
Birth defects and drug use
ALSO KNOWN AS: Congenital disabilities and substance abuse; developmental defects and substance abuse
DEFINITION: Congenital disabilities or developmental defects refer to problems that develop in the fetus during prenatal development. Congenital disabilities are physical abnormalities that are present at birth, regardless of the cause. One of the common causes of congenital disabilities is drug use during pregnancy.
Drugs as Teratogens
Teratogens (teratogenic substances) are environmental substances that cause congenital (or developmental) defects. Thousands of teratogenic substances exist, and many of them are drugs, including over-the-counter (OTC) drugs, prescription drugs, and illegal drugs of abuse.
Nearly all teratogens are most detrimental during the embryonic period (the second to eighth week of pregnancy). It is during this period in which organs form. Exposure to teratogenic substances may interfere with this normal organ formation. While drugs that are taken beyond the eighth week of pregnancy are not likely to cause actual congenital disabilities, they may interfere with the normal functioning of organs or may interfere with normal growth, causing intrauterine growth retardation. Drugs, like most other teratogens, affect the fetus when they cross the placenta along with oxygen and nutrients. Aspirin is one of the over-the-counter (OTC) drugs that is teratogenic, potentially causing bleeding in the pregnant woman and the fetus.
The use of prescription drugs may be necessitated because of a medical condition in the pregnant woman. If this is the case, the medical professional needs to prescribe a drug that is not teratogenic or one that is unlikely to harm the fetus. One formerly common prescription drug, the broad-spectrum antibiotic tetracycline, caused discoloration of primary and secondary teeth in utero. In the twenty-first century, another broad-spectrum antibiotic is used to treat infection, decreasing the likelihood of a resultant congenital disability.
Generally, when speaking of congenital disabilities and drug use, one more commonly attributes defects to tobacco (smoking), alcohol, marijuana, stimulants, sedatives, addictive substances (like heroin or cocaine), and hallucinogens, most of which are teratogenic. Smoking tends to cause heart defects and intrauterine growth retardation. Alcohol exposure most typically causes fetal alcohol spectrum disorder. This condition generally involves growth retardation and other physical and cognitive problems. No definite evidence exists about the teratogenic effects of marijuana, although the drug has been implicated in cases of small head circumference, neurological problems, and learning deficiencies. Investigations are ongoing into the effects of marijuana on prenatal development, especially because marijuana is the single most common drug used by pregnant women. The legalization of medical and recreational marijuana in the many states in the United States (US) has brought increased attention to the safety of its use during pregnancy, especially as many pregnant women turn to marijuana for its anti-nausea properties.
Stimulants (including amphetamines) and sedatives (including phenobarbital) seem to cause developmental defects within the nervous system. Cocaine has been found to cause placental abruptions, causing the deaths of pregnant women and babies, or premature delivery. Opioids like heroin often cause intrauterine growth retardation and cause infants to be born addicted. Also, newborns addicted to heroin or other opioids are likely to have learning disabilities later in life.
Hallucinogens (like LSD or belladonna) differ from the other categories of drugs in that they can cause congenital disabilities, even if they are taken years before pregnancy. Hallucinogens have been found to cause chromosomal damage at the time of use. Because chromosomes in egg cells (ova) and in spermatogenic cells may be damaged, a wide variety of congenital disabilities can occur. Similarly, if hallucinogens are used during early pregnancy, chromosomal damage may occur, leading to various types of congenital disabilities. Many pregnant drug users use more than one type of drug. This complicates the situation in that drugs may interact to have a significantly different and greater effect on the fetus.
Drug Treatment for Pregnant Women
Pregnant women who use heroin or other opioids are sometimes treated with methadone. While this is an effective immediate treatment, it does not prevent a fetus from being born addicted. Suboxone (also known as buprenorphine) is a drug used since the 1980s to treat opioid addiction (first used in the US for this purpose in 2002). According to the National Institute on Drug Abuse, the findings of a study published in 2022 suggest that buprenorphine may be a safe and effective alternative to methadone, the standard treatment for opioid dependence during pregnancy. Infants born to mothers on heroin, methadone, or Suboxone are evaluated using the neonatal abstinence (Finnegan) scale. The use of this scale determines the course of treatment in stopping the use of these substances.
Bibliography
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"Substance Use During Pregnancy - Maternal Infant Health." CDC, 15 May 2024, www.cdc.gov/maternal-infant-health/pregnancy-substance-abuse/index.html. Accessed 22 Aug. 2024.
"Substance Use in Pregnancy - StatPearls." NCBI, www.ncbi.nlm.nih.gov/books/NBK542330. Accessed 22 Aug. 2024.