Drugs, including medications and recreational drugs, may have effects during pregnancy on the pregnant woman and fetus that vary from the effects of the drug on people who are not pregnant. The Food and Drug Administration (FDA) in the United States reports that there are six million pregnancies with at least 50% of the women taking at least one medication. In addition a reported 5–10% of women of childbearing age use alcohol or other addictive substances. Of those who bear children, recreational drug use 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 and mental abnormalities, higher risk of stillbirth, neonatal abstinence syndrome (NAS), sudden infant death syndrome (SIDS), low birthweight, and others.
Drugs taken in pregnancy including over-the counter-medications, prescription medications, nutritional supplements, recreational drugs, and illicit drugs may cause harm to the mother or the unborn child. Tobacco, alcohol, marijuana, and illicit drug use while pregnant may be dangerous for the unborn baby and may lead to severe health problems and/or birth defects. Even small amounts of alcohol, tobacco, and marijuana have not been proven to be safe when taken while pregnant. In some cases, for example, if the mother has epilepsy or diabetes, the risk of stopping a medication may be worse than risks associated with taking the medication while pregnant. The mother's healthcare professional will help make these decisions about the safest way to protect the health of both the mother and unborn child. In addition to medications and recreational substances, some dietary supplements are important for a healthy pregnancy, however, others may cause harm to the unborn child.
Pregnancy categories
Categorizations of drugs based on safety in pregnancy varies by country.
Until 2014, the U.S. Code of Federal Regulations required that certain drugs and biological products be labelled specifically with respect to their effects on pregnant populations, including a definition of a "pregnancy category". These rules were enforced by the FDA, and medications that have been studied for their effects in pregnancy fell under the following Pregnancy Categories: A, B, C, D, or X depending on how they have been studied and what kind of results were found from the studies. In 2014, however, the FDA has developed a "Pregnancy and Lactation Labeling Rule (PLLR)" which requires product labels to include specific information related to the safety and effectiveness of medications to pregnant and lactating women. This ruling has removed the requirement of stating pregnancy categories in prescription drug labels.
Australia's categorization system takes into account birth defects, the effects around birth or when the mother gives birth, and problems that will arise later in the child's life due to the drug taken. The system places them into a category based on the severity of the consequences that the drug can have on the infant when it crosses the placenta.
Medications Medications during pregnancy must be carefully considered. Many drugs, medications, and nutritional supplements can affect fetal development or cause complications. For over-the-counter and prescription medications, healthcare professionals can help weigh the potential risks and benefits of taking medication while pregnant and if it is needed. Some medications may be necessary for the health and well being of both the mother and the unborn child, and some medications may come with a risk of harm to the unborn baby, but in some instances the benefits may outweigh the risks to the baby or mother.
Medications for pain
Short-term use of acetaminophen as directed is one of the only medications recommended for treating pain and fever in women who are pregnant. There is no established association with teratogenicity or elevated occurrence of birth defects and the usage of acetaminophen at any point during a pregnancy. There is potential for fetal liver toxicity in cases of maternal overdose, where the mother consumes more than the recommended daily dose.
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 is recommended that pregnant women avoid these medications or use them sparingly per physician recommendations.
Usage of aspirin for pain relief during pregnancy is not recommended. Aspirin use during pregnancy has not demonstrated an 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.
While aspirin should be avoided for use pain relief, low dose aspirin is used for prevention of preeclampsia and fetal growth restriction (FGR) in patients with previous risk factors (e.g. previous preeclampsia, multiple pregnancies, hypertension and diabetes).
Pain medications containing opioids For more information, see the below section on Recreational drugs
Pregnant women who use prescription medications containing opioids while pregnant may cause serious harm to the mother or unborn child. For some people, the risk of stopping a medication such as prescription opioids may be more serious than the risk of taking a medication.
Anticonvulsant medications Many commonly prescribed anticonvulsant medications are associated with an increased risk of birth defects such as neural tube defects, however, most women with epilepsy deliver healthy babies and have a healthy pregnancy. Women who have epilepsy often still require treatment to control or prevent seizures and therefore require very early advice (ideally before conceiving the child) from their doctor to determine the safest way to protect both the mother and unborn child.
Valproic acid and its derivatives such as sodium valproate and divalproex sodium, commonly used to prevent seizures and treat mood disorders, increase the risk of congenital malformations (birth defects) including neural tube defects if taken during pregnancy. There is evidence that an increased dose or increased exposure in utero is associated with an increased risk of lower scores on neurodevelopmental tests. Valproic acid use during pregnancy increases the risk of neural tube defects by approximately 20-fold. Evidence is conflicting for carbamazepine regarding any increased risk of congenital physical anomalies or neurodevelopmental disorders by intrauterine exposure. Similarly, children exposed to lamotrigine or phenytoin in the womb do not seem to differ in their skills compared to those who were exposed to carbamazepine.
Antacids Heartburn is a common symptom of late term pregnancy during which up to 80% of pregnant women have experienced it by the end of their third trimester. Heartburn often indicates the development of gastro-esophageal reflux disease (GERD), where the lower esophageal sphincter relaxes due to elevated progesterone levels causing increased frequency and severity of gastric reflux or heartburn. If heartburn appears after 20 weeks of gestational age or is severe and persistent, this can indicate other conditions including HELLP syndrome and preeclampsia.
Common antacids include aluminum hydroxide/magnesium hydroxide (Maalox) and calcium carbonate (Tums). Histamine H2 blockers and proton pump inhibitors, such as famotidine (Pepcid) and omeprazole (Prilosec), respectively, can also be used to help relieve heartburn, with no known teratogenic effects or congenital malformations. Aluminum hydroxide/magnesium hydroxide and calcium carbonate, when consumed, do not cross the placenta and are regarded as safe pharmacological options to treat heartburn, since there are no significant association with maldevelopment or injury to fetus.
Ginger and acupressure are common non-pharmacological options used to treat nausea and vomiting as alternatives to antacids, histamine H2 blockers, and proton pump inhibitors. Lifestyle modifications are often recommended as well. Recommended modifications can include avoiding fatty food, reducing size and frequency of meals, and reducing caffeine intake.
Antiacne Acne vulgaris (acne) can occur in pregnancy possibly due to the hormonal changes influencing sebum production. There are limited antiacne medications that are safe in pregnancy. External applications of azelaic acid, glycolic acid, or benzoyl peroxide (alone or combined with clindamycin or erythromycin) are the safest options to treat mild to moderate acne. Erythromycin is the antibiotic of choice for severe acne, barring the use of its estolate salt which risks maternal hepatotoxicity. Topical nicotinamide and topical zinc are safe, however, there are no FDA pregnancy category ratings. Topical salicylic acid and topical dapsone are classified as FDA pregnancy category C. Acne medications to avoid during pregnancy include oral isotretinoin and topical tazarotene as there have been reports of birth defects. As safety data is lacking, the use of topical retinoids, such as adapalene and tretinoin, is not recommended. Antiandrogenic drugs, including spironolactone and cyproterone acetate, should be avoided. If planning to conceive while using contraindicated medications, a washout and waiting period before conception is advised. A herbal product, vitex agnus-castus should not be used during gestation due to undesirable hormonal effects.
Safety data supports the use of blue and red light therapy as non-drug treatments to consider. Personal hygiene and a healthy lifestyle also help, however dietary restriction and abrasive agents found in facial cleaning products are not beneficial. As there are limited options to safely treat acne in pregnancy, shared decision-making between the health care provider and client is recommended.
Anticoagulants 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 people 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.
Warfarin (brand name Coumadin) is a commonly prescribed blood thinner both in the inpatient and outpatient hospital settings. In pregnant women, warfarin is contraindicated and should be avoided as it crosses the placental barrier. Additionally, warfarin is listed as Pregnancy Category D, which means it has a risk of harming the fetus. However, it has been shown that daily warfarin doses up to 5 mg may be beneficial for pregnant women who are at higher risk of thromboembolism.