Codeine is an opioid painkiller used for treating mild to moderate pain. Codeine is also found in many cough medications and anti-diarrhea medicines. Because of its long history, many people assume it is safe to use, even during pregnancy. However, there is growing evidence linking birth defects to maternal use of codeine during pregnancy. Unfortunately, the safety labeling still fails to warn of this severe side effect.
Codeine is an opiate (narcotic) analgesic, used to alleviate mild to moderate pain. It treats pain by making changes to the central nervous system, changing the way the body senses pain. Codeine is also a type of cough medication called an “antitussive,” which reduces coughing by decreasing activity in the part of the brain that causes coughing.
Codeine may be used alone, but is more frequently used in combination with other painkilling medications, such as acetaminophen, aspirin, or ibuprofen. These combination medications have a synergy that makes them more effective than either drug alone.
The list of medications that contain opioid painkillers is very long. Some of the most popular opioid medications include:
- Tylenol-3, 4, Tylenol Plus Codeine
- Some cough medicines
Codeine and Pregnancy
About 4 million babies are born in the United States every year. The leading cause of infant mortality is birth defects. Though not all birth defects are fatal, around 3% of babies are born with some type of birth defect, and 1% have a heart defect. Medications are a major contributor to birth defects, because many pass through the placenta and affect a developing baby. Medications pose the greatest risk to a developing baby either just before or during the first trimester of pregnancy.
If you took codeine during pregnancy, you probably had no idea that it could cause problems for your developing baby. This is because the drug labeling does not include thorough information. In fact, codeine is categorized as Pregnancy Class C. This means that it is not known whether the drug will cause birth defects. Animal studies have shown risks to a developing fetus, but human studies are still inconclusive. The benefit of using the medication may still outweigh the risk.
However, the risk may be under-estimated. Though codeine is a very popular medication, there have not been very many studies of its effects on a developing baby. Of the studies that have been conducted, several have found links between codeine and birth defects — particularly cleft lip, cleft palate, and heart defects.
Scientific Studies of Codeine During Pregnancy
In an effort to take a closer look at the link between codeine and birth defects, the Centers for Disease Control (CDC) funded the following study: “Maternal treatment with opioid analgesics and risk for birth defects.”
Researchers used information from the National Birth Defects Prevention Study. Of 17,449 who had a baby with a birth defect, 2.9% had used an opioid painkiller during pregnancy. Of the roughly 7,000 women in the study whose babies had no defects, only 2% had used an opioid painkiller. All of the women lived in the same regions and gave birth at around the same time.
The researchers also found that the risk of certain heart defects was 1.4-times greater for babies born to women who had used an opioid painkiller.
During the study, many women said that the reason they took the medications during pregnancy was due to injury, chronic illnesses, surgery pain, and infections. Many of them did not realize that the painkillers may have adverse effects on a developing baby.
Codeine and Birth Defects
The researchers found a higher risk of the following birth defects:
- Spina bifida (neural tube birth defect)
- Hydrocephaly (excess fluid in the brain)
- Glaucoma (eye defect)
- Gastroschisis (abdominal wall defect; internal organs protrude outside the body)
- Heart defects
- Ventricular septal defect (hole in the wall between the lower-left and lower-right heart chamber)
- Hypoplastic left heart syndrome (severe under-development of the left side of the heart). The risk of this birth defect was doubled.
- Atrial septal defect (hole in the wall between the upper-left and upper-right heart chamber)
- Tetralogy of Fallot (four severe heart defects that cause low oxygen in the bloodstream, major circulation problems)
- Pulmonary valve stenosis (severe narrowing of the pulmonary heart valve)