National Toxicology Program

Introduction

Drugs use by pregnant women can result in harm to unborn children. The March of Dimes provides information about pregnancy and the use of legal drugs such as tobacco and alcohol and illegal drugs such as cocaine, PCP, and heroin. Because some prescription and over-the-counter drugs can also harm unborn children, the March of Dimes recommends that pregnant women speak to their doctors before taking any medication.  Additional information about smoking and drinking alcohol while pregnant is available in the Center for Evaluation of Risks to Human Reproduction (CERHR) website under Common Concerns and Exposures.

Cocaine use during pregnancy

The March of Dimes (MOD 2004) offers the following information about cocaine use during pregnancy:

What are the risks with use of cocaine during pregnancy?

Cocaine use during pregnancy can affect a pregnant woman and her unborn baby in many ways. During the early months of pregnancy, it may increase the risk of miscarriage. Later in pregnancy, it can trigger preterm labor (labor that occurs before 37 weeks of pregnancy) or cause the baby to grow poorly. As a result, cocaine-exposed babies are more likely than unexposed babies to be born with low birthweight (less than 5½ pounds). Low-birthweight babies are 20 times more likely to die in their first month of life than normal-weight babies, and face an increased risk of lifelong disabilities such as mental retardation and cerebral palsy. Cocaine-exposed babies also tend to have smaller heads, which generally reflect smaller brains.

Some studies suggest that cocaine-exposed babies are at increased risk of birth defects, including urinary-tract defects and, possibly, heart defects. Cocaine also may cause an unborn baby to have a stroke, which can result in irreversible brain damage or a heart attack, and sometimes death.

Cocaine use also may cause the placenta to pull away from the wall of the uterus before labor begins. This condition, called placental abruption, can lead to extensive bleeding and can be fatal for both mother and baby. (Prompt cesarean delivery, however, can prevent most deaths.)

Babies who were regularly exposed to cocaine before birth may score lower than unexposed babies on tests given at birth to assess the newborn’s physical condition and overall responsiveness. They may not do as well as unexposed babies on measures of motor ability, reflexes, attention and mood control, and they appear less likely to respond to a human face or voice.

Babies who are regularly exposed to cocaine before birth sometimes have feeding difficulties and sleep disturbances. As newborns, some are jittery and irritable, and they may startle and cry at the gentlest touch or sound. Therefore, these babies may be difficult to comfort and may be described as withdrawn or unresponsive. Other cocaine-exposed babies “turn off” surrounding stimuli by going into a deep sleep for most of the day. Generally, these behavioral disturbances are temporary and resolve over the first few months of life. Some studies suggest that cocaine-exposed babies have a greater chance of dying of sudden infant death syndrome (SIDS). However, other studies suggest that poor health practices that often accompany maternal cocaine use (such as use of other drugs) also may play a major role in these deaths.

What is the long-term outlook for babies who were exposed to cocaine before birth?

Some studies suggest that most children who are exposed to cocaine before birth have normal intelligence. This is encouraging, in light of earlier predictions that many of these children would be severely brain damaged. A 2002 study at Harvard Medical School and Boston University found that children up to age 2 who were heavily exposed to cocaine before birth scored just as well on tests of infant development as lightly exposed or unexposed children. However, other studies suggest that cocaine may sometimes affect mental development, possibly lowering IQ levels.

A 2002 study at Case Western Reserve University found that cocaine-exposed 2-year-olds were twice as likely as unexposed children from similar low socioeconomic backgrounds to have significant delays in mental development (14 percent and 7 percent, respectively). It is not known whether these children will continue to have learning problems when they reach school age.

Studies are inconclusive regarding the risk of learning and behavioral problems. Studies from the National Institute on Drug Abuse suggest that most adolescents who were exposed to cocaine before birth seem to function normally. However, some may have subtle impairments in the ability to control emotions and focus attention that could put them at risk of behavioral and learning problems. Other studies suggest that cocaine exposure may adversely affect language abilities. Researchers continue to follow cocaine-exposed children through their teen years to clarify their long-term outlook.

Marijuana use and pregnancy

Marijuana is often mistakenly viewed as a "safe" drug.  However, a study funded by the National Institute on Drug Abuse (NIDA) and the National Institute on Child Health and Human Development (NICHD) suggests that exposure to cannabinoids, psychoactive chemicals present in marijuana, can affect early embryonic development.   More information about this study can be found at:  http://www.nih.gov/news/pr/oct96/nida-11.htm and http://www.kumc.edu/Pulse/breaknews/Break_news101096.html.   General information concerning the effects of marijuana use during pregnancy can be located using http://lib.adai.washington.edu/biblist.htm.

The March of Dimes (MOD 2004) offers the following information about marijuana use and pregnancy.

What are the risks with use of marijuana during pregnancy?

Some studies suggest that use of marijuana during pregnancy may slow fetal growth and slightly decrease the length of pregnancy (possibly increasing the risk of premature delivery). Both of these factors can increase a woman’s chance of having a low-birthweight baby. These effects are seen mainly in women who use marijuana regularly (six or more times a week).

After delivery, some babies who were regularly exposed to marijuana in the womb appear to undergo withdrawal-like symptoms including excessive crying and trembling.

Couples who are planning pregnancy also should keep in mind that marijuana can reduce fertility in both men and women, making it more difficult to conceive.

What is the long-term outlook for babies exposed to marijuana before birth?

There have been a limited number of studies following marijuana-exposed babies through childhood. Some did not find any increased risk of learning or behavioral problems. However, others found that children who are exposed to marijuana before birth are more likely to have subtle problems that affect their ability to pay attention and to solve visual problems. Exposed children do not appear to have a decrease in IQ.

The facts about prescription and store-bought medicines

Many medicines are relatively safe to take while you are pregnant, but some are not. Here are some tips from the National Women’s Health Information Center (National Women’s Health Information Center 2002) for using medicines safely:

Many drugs that you can buy over-the-counter (OTC) in drug and discount stores, and drugs your health care provider prescribes are thought to be safe to take during pregnancy, although there are no medicines that are proven to be absolutely safe when you are pregnant. Many of these products tell you on the label if they are thought to be safe during pregnancy. If you are not sure you can take an OTC product, ask your health care provider.

Some drugs are not safe to take during pregnancy. Even drugs prescribed to you by your health care provider before you became pregnant might be harmful to both you and the growing fetus during pregnancy. Make sure all of your health care providers know you are pregnant, and never take any drugs during pregnancy unless they tell you to.

Also, keep in mind that other things like caffeine, vitamins, and herbal teas and remedies can affect the growing fetus. Talk with your health care provider about cutting down on caffeine and the type of vitamins you need to take. Never use any herbal product without talking to your health care provider first.

See the following sites for more information on prescription and over-the-counter medicines:

http://www.pdrhealth.com/

http://www.nlm.nih.gov/medlineplus/druginformation.html

http://www.fda.gov/womens/getthefacts/pregnancy.html