According to the Organization of Teratology Information Services (OTIS), during the early stages of pregnancy, cocaine exposure may increase the chances of miscarriage. In the later parts of pregnancy, cocaine use may lead to placental abruption. Placental abruption can trigger severe bleeding, preterm labor, and fetal death. (Women who use cocaine while expecting also have a 25-percent greater risk of preterm labor, according to the American College of Obstetricians and Gynecology).
The elimination of cocaine is slower in a fetus than in an adult. This means that cocaine remains in the baby's body much longer than it does in your body. So, chances are high that babies who are exposed to cocaine during pregnancy will suffer from the following withdrawal symptoms: tremors, sleeplessness, muscle spasms, and difficulties feeding. Some experts believe that learning difficulties may result as the child gets older. Defects of the genitals, kidneys, and brain are also possible, according to the APA.
LSD, PCP, and ketamine (also known as the "date rape drug") are all hallucinogenics, meaning people on these drugs may see and feel things that aren't actually happening. For users, the events they are experiencing are very real, which can lead to dangerous behavior.
Although no conclusive tests have been done in these drugs during pregnancy, the APA reports that "PCP use during pregnancy can lead to low birth weight, poor muscle control, brain damage, birth defects, and withdrawal symptoms" in newborns.
Heroin is nonteratogen, that is, it's not a substance that causes deformities in a developing baby. It is difficult to glean information from studies done on heroin and pregnancy because often times heroin users are also frequently using other substances.
What we do know is that heroin addiction, because of its associated poor nutrition and highly stressed day-to-day life, makes for a very complicated pregnancy. A baby born to a heroin addict will have a heroin "need" as well.
Because of the many risks to both mother and baby, care of a heroin-addicted pregnant woman should be under the care of a Maternal-Fetal Medicine specialist (perinatologist). If a mother tries to kick her habit while pregnant, she'll undoubtedly go through withdrawal, and so also might the baby (studies note some stillbirths due to this complication).
The March of Dimes reports that although heroin can be sniffed, snorted, or smoked, many users choose to inject the drug into a muscle or vein. This introduces yet another risk for pregnant users: contracting HIV (the virus that causes AIDS) and passing it on to their babies.
It is important to note that pregnant women who use heroin should not attempt to quit the drug cold turkey. This can put their babies at increased risk of death, reports the March of Dimes. To kick the habit, women should instead consult a healthcare provider or drug treatment center and inquire about treatment with a drug called methadone. "Although infants born to mothers taking methadone also have withdrawal symptoms, they can be safely treated in the nursery and generally do better than babies born to women who continue to use heroin," says the March of Dimes.