Substance Use During Pregnancy

Some research suggests that drinking more than 7 cups of coffee a day may increase the risk of having a stillbirth, preterm birth, low-birth-weight baby, or miscarriage.

Some experts recommend limiting coffee consumption and drinking decaffeinated beverages when possible.

Aspartame, an artificial sweetener, appears to be safe during pregnancy when it is consumed in small amounts, such as in amounts used in normal portions of artificially sweetened foods and beverages.

Anyone (including pregnant women) with phenylketonuria, an unusual disorder of amino acid metabolism, should not consume any aspartame.

Cigarette smoking poses risks to pregnant women and fetuses. Women who are trying to get pregnant or are pregnant should try to quit smoking. Health care professionals can provide resources about smoking cessation programs.

The most consistent effect of smoking on the fetus during pregnancy is

• A reduction in birth weight (growth restriction)

The more a woman smokes during pregnancy, the less the baby is likely to weigh.

Birth defects of the heart, brain, and face are more common among babies of women who smoke cigarettes.

Also, the risk of the following may be increased:

• Sudden infant death syndrome (SIDS)

• A mislocated placenta (placenta previa)

• Premature detachment of the placenta (placental abruption)

• Prelabor rupture of the membranes (containing the fetus)

• Preterm labor

• Uterine infection

• Miscarriage

• Stillbirth

• Preterm birth

Nicotine stimulates the release of hormones that constrict the vessels supplying blood to the uterus and placenta, so that less oxygen and fewer nutrients reach the fetus.

Because of the possible harmful effects of smoking during pregnancy, pregnant women should make every effort to not smoke during pregnancy, including discussing strategies with their doctor.

Pregnant women should avoid exposure to secondhand smoke because it may harm the fetus.

Drinking alcohol during pregnancy is the leading known cause of birth defects. Because the amount or pattern of drinking alcohol required to cause fetal alcohol syndrome is unknown, pregnant women are advised to abstain from drinking any alcohol.

The risk of miscarriage almost doubles for women who drink alcohol in any form during pregnancy, especially if they drink heavily. Risk is probably related to amount of alcohol consumed, but no amount is known to be risk-free.

Fetal alcohol syndrome is one of the most serious consequences of drinking during pregnancy. Binge drinking as few as 3 drinks a day can cause this syndrome. It occurs in about 2 of 1,000 live births. This syndrome includes the following:

• Inadequate growth before birth or after birth

• Birth defects of the face

• A small head (microcephaly), probably caused by inadequate growth of the brain

• Intellectual disability

• Abnormal behavioral development

• Less commonly, joint abnormalities and heart defects

Use of amphetamines during pregnancy may result in birth defects, especially of the heart, and possibly inadequate growth before birth.

The drugs may cause the blood vessels in the fetus to narrow, reducing the amount oxygen the fetus gets.

Also, these drugs increase the risk of the following:

• Stillbirth

• Premature detachment of the placenta (placental abruption)

• Possibly birth defects

taken during pregnancy may cause the blood vessels that carry blood to the uterus and placenta to narrow (constrict). Then, less oxygen and fewer nutrients reach the fetus.

• Miscarriage

• Inadequate growth of the fetus

• Preterm detachment of the placenta (placental abruption)

• Preterm birth

• Stillbirth

• Birth defects (including brain and spinal cord, urinary tract, and bone defects)

Hallucinogens may, depending on the drug, increase the risk of the following:

• Miscarriage

• Preterm labor and delivery

• Withdrawal syndrome in the fetus or newborn

The main component of marijuana (cannabis), tetrahydrocannabinol, can cross the placenta and thus may affect the fetus. No amount of marijuana is considered safe in pregnancy though birth defects are not increased in studies. However, recent studies have suggested that marijuana use in pregnancy may be linked to low birth weight and childhood concerns including attention, learning, and behavioral problems, and changes in brain development and function.

Opioids are used to relieve pain, but they also cause an exaggerated sense of well-being, and if used too much, they can cause dependence and addiction.

withdrawal symptoms 6 hours to 8 days after birth. However, use of opioids rarely results in birth defects.

Use of opioids during pregnancy increases the risk of complications during pregnancy, such as

• Miscarriage

• Abnormal presentation of the baby

• Preterm delivery

Babies of heroin users are more likely to be born small.