Drug use in pregnancy: what’s safe, what’s not

While pregnancy and motherhood is every woman’s dream, the journey of nine months comes with a lot of uncertainties and trepidations. From the moment a pregnancy test comes back positive, a woman’s life changes…what to eat, what not to eat, what to do, what not to do and several other questions for the safety of the fetus begin to plague the mother’s mind. However, the period of pregnancy also comes with its own baggage of health challenges as hormonal level rises and fluctuates.

For some women, hormonal changes may cause symptoms ranging from mild ones like acne breakouts to more severe ones like morning sickness, fever and in some cases, full blown malaria episode. It is a common practice, especially in this part of the world, to depend on self medication through the use of over the counter (OTC) drugs but for a pregnant woman, what medications are safe or what other medications can bring about some conditions that may affect the effective development of a healthy baby?

An expectant mother recently sent in this question to an online women forum “I am 17 weeks pregnant and was diagnosed with malaria. My doctor gave me a certain drug for the treatment but am worried. I would like other experienced mothers to tell me the best malaria medicine to take during pregnancy and if anyone has taken it during pregnancy with no issues.” This woman is not alone as many other mothers find themselves in the same predicament.

According to experts, the first 8 to 12 weeks of pregnancy are crucial, so it is important to take proper medications. Over the counter medicines should be avoided in this phase of pregnancy. This is because drugs diffuse across the placenta similarly to the way they cross other epithelial barriers. Whether and how quickly a drug crosses the placenta depends on the drug’s molecular weight, extent of its binding to another substance like a carrier protein, area available for exchange across the placental villi and amount of drug metabolized by the placenta. Most drugs with a molecular weight of less than 500 daltons readily cross the placenta and enter the fetal circulation. Substances with a high molecular weight, that is, protein-bound drugs, usually do not cross the placenta. Generally, equilibration between maternal blood and fetal tissues takes at least 30 to 60 min.

Pharmacists say that a drug’s effect on the fetus is determined largely by fetal age at exposure, drug potency and drug dosage. Based on Fetal age, the following drug effects may be experienced:

Before the 20th day after fertilization: Drugs given at this time typically have an all-or-nothing effect killing the embryo or not affecting it at all. Teratogenesis (the process by which congenital malformations are produced in an embryo or fetus) is unlikely to occur during this stage.

Between 20 and 56 days after  fertilization which is known as before organogenesis: Teratogenesis is most likely at this stage. Drugs reaching the embryo during this stage may result in spontaneous abortion, a sublethal gross anatomic defect (true teratogenic effect), or covert embryopathy (a permanent subtle metabolic or functional defect that may manifest later in life), or the drugs may have no measurable effect.

After organogenesis (in the second and third trimesters): Teratogenesis is unlikely, but drugs may alter growth and function of normally formed fetal organs and tissues. As placental metabolism increases, doses must be higher for fetal toxicity to occur.

Despite widespread concern about drug safety, exposure to therapeutic drugs accounts for only two to three per cent of all fetal congenital malformations; most malformations result from genetic, environmental, or unknown causes.

Pharmacist Simon Dazams while speaking on the subject said “It is important for women to avoid OTC medications especially during pregnancy due to complications that may severely affect the health of the baby. Drug use in pregnancy is a very sensitive thing because most drugs are not tested on pregnant women. Therefore, drug use is usually not recommended unless the potential benefits outweigh the potential risk to the fetus.

However, some drugs are relatively safe with prescriptions from doctors and dosage maintained by a certified pharmacist because dosage is a very important factor when it comes to measuring potential risks, if there will be any.”

According to Dazams, some over the counter (OTC) medications that could be taken during pregnancy may include Benadryl also known as diphenhydramine. “Diphenhydramine is an antihistamine mainly used to treat allergies. It is also used for insomnia, symptoms of common cold and nausea. It is used by mouth, injection into a vein, and injection into a muscle. There is no clear risk of harm when used during pregnancy; however, use during breastfeeding may not be recommended.”

He added that acetaminophen commonly called tylenol which is a pain reliever and a fever reducer used to treat many conditions such as headache, muscle aches, arthritis, backache, colds or fevers can be administered during pregnancy while stressing the need for consultation with medical experts before use. “Inasmuch as these and some others are presumed safe, it is imperative that women go through medical consultations and get prescriptions from certified medical practitioners before making use of drugs while pregnant.”

However, Dazams explained that some drugs are beneficial in pregnancy and withholding them poses several risks. “For instance, folic acid is very good for pregnant women and they may not necessarily need a prescription to get it. The benefits of folic acid are numerous. Folic acid helps the neural tube close correctly and prevents major defects like Spina bifida, which is incomplete development of the spinal cord, anencephaly, which is incomplete development of the brain and other conditions like cleft lip and palate, miscarriages and low birth weight. So, if at all a pregnant woman must take any drug without prescription, it is okay to take folic acid, vitamin B. The truth is she cannot get too much folic acid from foods that contain it. Prenatal vitamins sometimes do not contain the recommended dose of Folic acid so it can be taken on its own.”

However, OTC medications that should be avoided in the first trimester of pregnancy, experts say include:


Painkillers such as ibuprofen and aspirin can affect the fetus at any stage of pregnancy. If you have body pain or mild headache, then natural therapy works the best. Massage the area for natural relief. Any type of painkiller should be avoided in pregnancy.

Antifungal medicines

Yeast infection is a common problem in pregnancy. But, avoid having antifungal medicines as it may affect your pregnancy. Medicine for acne

During pregnancy, your body goes through lots of hormonal changes. So, acne and breakouts can be a common thing. Avoid having medicines for acne because it may affect your hormones. Medicines like Retin A and Accutane should be avoided during pregnancy.

Cold tablets

Cold tablets have paracetamol, so they should be avoided during pregnancy. High dose of paracetamol may also affect the fetus in first trimester of pregnancy. Nasal sprays and natural treatments for cold can help to provide some relief.


Antidepressants containing paroxetine should be completely avoided in the first two trimesters of pregnancy. High dose of paroxetine may cause birth defects in the baby. Natural remedies would work best in pregnancy.

Antiallergy medicines

Avoid having antiallergy tablets during pregnancy, as it may affect the fetus. If you have an allergy, then heal it in a natural way. Stay away from dust, use dust free air conditioner and change all your filters. Have lots of water to reduce your allergy.


Antibiotics such as streptomycin and tetracycline may not be safe to have during pregnancy. If you need to have antibiotics, talk to your doctor. Your doctor would advice you on mild forms of antibiotics that might be safe during pregnancy.


Natural herbs may also pose danger to the developing fetus during pregnancy. There are some common herbs that should be completely avoided during pregnancy. Aloe Vera, black cohosh, ginseng, rosemary, yarrow and pennyroyal are some of them.

Additional information from webMD

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