Drugs in pregnancy
Around 5–10% of women of childbearing age abuse alcohol or drugs. This can have serious consequences to the health of not only the mother, but also the fetus as many medications can cross the placenta and reach the fetus. Some of the consequences on the babies include physical abnormalities, higher risk of stillbirth, neonatal abstinence syndrome, sudden infant death syndrome, and others.
Pregnancy categories
U.S. Code of Federal Regulations requires that certain drugs and biological products must be labelled very specifically with respect to their effects on pregnant populations, including a definition of a "pregnancy category". These rules are enforced by the Food and Drug Administration. The FDA does not regulate labelling for all hazardous and non-hazardous substances and some potentially hazardous substances are not assigned a pregnancy category.Australia’s categorizations system takes into account the birth defects, the effects around the birth or when the mother gives birth, and problems that will arise later in the child's life caused from the drug taken. The system places them into a category of their severity that the drug could cause to the infant when it crosses the placenta.
Medications
Some medications can adversely affect a fetus, but in some cases the benefits outweigh the risks. Diabetes mellitus during pregnancy may need intensive therapy with insulin to prevent complications to mother and baby. Pain management for the mother is an important area where an evaluation of the benefits and risks is needed. NSAIDs such as ibuprofen and naproxen are probably safe for use for a short period of time, 48–72 hours, once the mother has reached the second trimester. If taking aspirin for pain management the mother should not take a dose higher than 100 mg.Anticonvulsants
, and its derivatives such as sodium valproate and divalproex sodium, causes cognitive deficit in the child, with an increased dose causing decreased intelligence quotient. On the other hand, evidence is conflicting for carbamazepine regarding any increased risk of congenital physical anomalies or neurodevelopmental disorders by intrauterine exposure. Similarly, children exposed lamotrigine or phenytoin in the womb do not seem to differ in their skills compared to those who were exposed to carbamazepine.Pain Medications
The most common over-the-counter pain relieving medications include aspirin, acetaminophen, and non-steroidal anti-inflammatory drugs, which include naproxen, ibuprofen, among others. The safety of these medications vary by class and by strength.Usage of aspirin has not demonstrated increased risk of spontaneous abortion within the early weeks of pregnancy. However, its usage during organogenesis and the third trimester can lead to elevated risk of intrauterine growth retardation and maternal hemorrhage.
Ibuprofen and naproxen have not frequently been studied during pregnancy, but recent studies do not show increased risk of spontaneous abortion within the first six weeks of pregnancy. However all NSAIDs showed association with structural cardiac defects with usage during the early weeks of pregnancy. When ibuprofen and naproxen are used within the third trimester there is a significant increase in the risk of premature closure of the ductus arteriosus with primary pulmonary hypertension in the newborn. Between the lack of studies of the effect of ibuprofen and naproxen on pregnancy, it recommended to not take these medications or to use them sparingly per doctor recommendations.
Acetaminophen can be used throughout pregnancy. There is no established association with teratogenicity or elevated occurrence of birth defects and the usage of acetaminophen at any point during a pregnancy. However there is potential for fetal liver toxicity in cases of maternal overdose, where the mother consumes more than the recommended daily dose.
Antihistamines
can be split into first and second generation categories. First generation antihistamines can include diphenhydramine, chlorpheniramine, hydroxizine, and doxepin. Second generation antihistamines include loratadine, cetrizine, and fexofenadine. Antihistamines often are used in early pregnancy for the treatment of nausea and vomiting along with symptoms of asthma and allergies. First generation antihistamines have the ability to cross the blood-brain barrier which can result in sedative and anticholinergic effects while effectively treating allergic reactions, nausea and vomiting of pregnancy. On the other hand second generation antihistamines do not cross the blood-brain barrier, thus eliminating sedating effects. Currently there is a lack of association between prenatal antihistamine exposure and birth defects.Anticoagulants
are medications that prevent the blood from forming clots and are also known as blood thinners. These medications are commonly used for both prevention and treatment in patients who are at risk for or have experienced a heart attack, stroke, or venous thromboembolism. Pregnancy increases the risk of clot formation in women due to elevated levels of certain clotting factors and compounds in the body, and the risk increases even more immediately after birth and remains elevated up to 3 months after delivery. Anticoagulants must be prescribed with caution as these medications can have negative health consequences for the developing baby and need to consider dosing and medication management options.Recreational drugs
Alcohol
Alcohol passes easily from the mother's bloodstream through the placenta and into the bloodstream of the fetus. Since the fetus is smaller and does not have a fully developed liver, the concentration of alcohol in its bloodstream lasts longer increasing the chances of detrimental side effects. The severity of effects alcohol may have on a developing fetus depends upon the amount and frequency of alcohol consumed as well as the stage of pregnancy. Rates of alcohol consumption can generally be categorized in one of three ways: heavy drinking, moderately high drinking, and binge drinking. Heavy drinking and binge drinking are closely associated with a higher risk of fetal alcohol spectrum disorders. The most severe form of FASD is fetal alcohol syndrome. This used to be the only diagnosis for fetal disorders due to alcohol consumption but the term was broadened to a "spectrum" due to the variety of abnormalities observed in newborns. This was most likely because of the different amounts of alcohol ingested during pregnancy indicating that there is not a clear, specific dose that determines if a fetus will be affected by alcohol or not. This is why it is very important for pregnant women to abstain from alcohol use altogether. FAS is characterized by slower physical growth, distinct facial abnormalities including smooth philtrum, thin vermilion, and short palpebral fissures, neurological deficits, and/or smaller head circumference. Other problems associated with FASD include delayed or uncoordinated motor skills, hearing or vision problems, learning disabilities, behavior problems, and inappropriate social skills compared to same-age peers. Those affected are more likely to have trouble in school, legal problems, participate in high-risk behaviors, and develop substance use disorders themselves.Cannabis
Cannabis consumption in pregnancy might be associated with restrictions in growth of the fetus, miscarriage, and cognitive deficits. Cannabis is the most frequently used illicit drug amongst pregnant women. Tetrahydrocannabinol, an active ingredient in cannabis, can both cross the placenta and accumulates in high concentrations in breast milk.Tobacco
Tobacco is the most commonly used substance among pregnant women, at 25%. Similar to cocaine, nicotine is able to cross the placenta and accumulates within fetal tissues. Based on a literature review conducted between 2007 and 2008, children born to women who smoked heavily were more susceptible to behavioral problems such as ADHD, poor impulse control, and aggressive behaviors. A number of studies have shown that tobacco use is a significant factor in miscarriages among pregnant smokers. Tobacco contains carbon monoxide, which has the potential to prevent the fetus from receiving sufficient oxygen. Other health concerns tobacco poses are premature birth, low birth weight, and an increase risk of sudden infant death syndrome of up to three times compared to infants not exposed to tobacco. Smoking and pregnancy, combined, cause twice the risk of premature rupture of membranes, placental abruption and placenta previa. In addition to the fetus, women in general who smoke heavily are less likely to become pregnant.Cocaine
Use of cocaine in pregnant women can lead to cardiovascular complications like hypertension, myocardial infarction and ischemia, renal failure, hepatic rupture, cerebral ischemia, cerebral infarction, and maternal death. Cardiac muscles become mores sensitive to cocaine in pregnancy, in the presence of increasing progesterone concentrations. A systematic review and meta-analysis found that cocaine use leads to increased risk for perinatal outcomes: preterm delivery, low birth weight or reduced birth rate, small size and earlier gestational age at delivery.No specific disorders or conditions have been found to result for people whose mothers used cocaine while pregnant. Studies focusing on children of six years and younger have not shown any direct, long-term effects of prenatal cocaine exposure on language, growth, or development as measured by test scores. PCE also appears to have little effect on infant growth. However, PCE is associated with premature birth, birth defects, attention deficit hyperactivity disorder, and other conditions. The effects of cocaine on a fetus are thought to be similar to those of tobacco and less severe than those of alcohol.
Opioids
s include heroin, fentanyl, painkillers such as oxycodone and methadone. Women who abuse opioids during pregnancy are at a higher risk for premature birth and for lower birth weight. There is no consensus on the effects on cognitive abilities.Opioid abuse is the main cause of neonatal abstinence syndrome, which is where the baby experiences withdrawals from the drug they were exposed to during the pregnancy. Typical symptoms may include tremors, convulsions, twitching, excessive crying, poor feeding or sucking, slow weight gain, breathing problems, fever, diarrhea, and vomiting among other symptoms.
Methamphetamine
are a class of drugs that provide stimulant like effects, including euphoria and alertness. Use of methamphetamine is detrimental to pregnant women and to the fetus. The drug crosses the placenta and affect the fetus during the gestational stage of pregnancy. In a meta analysis, researchers found that methamphetamine use in pregnancy had an association with babies born with earlier gestational age at delivery, lower birth weight, and smaller head circumference.Methamphetamine is neurotoxic, which is concerning because prenatal methamphetamine exposure has shown to negatively impact brain development and behavioral functioning. A 2019 study further investigated neurocognitive and neurodevelopmental effects of prenatal methamphetamine exposure. This study had two groups, one containing children who were prenatally exposed to methamphetamine but no other illicit drugs and one containing children who met diagnosis criteria for ADHD but were not prenatally exposed to any illicit substance. Both groups of children completed intelligence measures to compute an IQ. Study results showed that the prenatally exposed children performed lower on the intelligence measures than their non-exposed peers with ADHD. The study results also suggest that prenatal exposure to methamphetamine may negatively impact processing speed as children develop.