Taking any drug/medication in pregnancy can be a challenge for the healthcare provider and the pregnant woman. Many obstetricians are reluctant to give many medications during pregnancy especially in the first twelve weeks but, in some cases where the woman has a medical disorder requiring medications, this can pose severe challenges. There is no doubt that certain drugs used by the pregnant woman reaches the fetus and cause harm.
The pregnant woman and drugs
In pregnancy, drug treatment and use present a special concern due to the threat of potential teratogenic effects of the drug and physiologic adjustments in the mother in response to the pregnancy. Various changes occur in the body during pregnancy and these affect the absorption, actions and side effects of various medications. All healthcare providers must be aware of this and must avoid prescribing medications to pregnant women if they are not sure of these effects. Physicians are encouraged to enquire from all women of reproductive age if they are pregnant, or have the possibility of pregnancy, prior to prescribing any medications. Total avoidance of medications use treatment in pregnancy is not possible and may be dangerous because some women enter pregnancy with medical conditions that require ongoing and episodic treatment (e.g. asthma, epilepsy, hypertension). Ideally these women should be under the care of an experienced and knowledgeable obstetrician/ physician.
Drug use during pregnancy. How common is it?
It has been estimated that more than 50% of pregnant women take prescription or nonprescription (over-the-counter) drugs or use social drugs (such as tobacco and alcohol) or illicit drugs at some time during pregnancy, and use of drugs during pregnancy appears to be increasing in many countries, including Anguilla. Some of these medications might be medically indicated but it is felt that many of these drugs can be avoided during pregnancy. Doctors and other healthcare providers must do a better job in educating the community of the dangers of drug use during pregnancy.
Are all drug use dangerous during pregnancy?
In general, drugs unless absolutely necessary should not be used during pregnancy because drugs taken by a pregnant woman can reach the fetus and harm it by crossing the placenta. In some women, for instance those with medical disorders, avoiding medications when pregnant may be dangerous and the doctor has to make the decision which drug is the safest to use, bearing in mind that the health of the mother is always the first priority.
History has proven that some drugs can be extremely dangerous to the fetus if used in pregnancy. In the 1960’s pregnant women who took thalidomide for nausea and vomiting gave birth to children with phocomalia. Various other examples of teratogenic effects of drugs are known. It has been documented that congenital abnormalities caused by human teratogenic drugs account for less than 1% of total congenital abnormalities. In the USA, in 1979, Food and Drug Administration developed a system that determines the teratogenic risk of drugs by considering the quality of data from animal and human studies. FDA classifies various drugs used in pregnancy into five categories: A, B, C, D and X. Category A is considered the safest category and category X is absolutely contraindicated in pregnancy. This provides therapeutic guidance for the clinician who can then discuss this with the pregnant woman.
Over-the-counter drugs
Many individuals use over-the-counter drugs and do not realize they can be very dangerous especially to the woman who is pregnant. While many over-the-counter drugs can be used during pregnancy, under a physician’s supervision, some are known to be unsafe. As a general rule if you are pregnant do not use over-the-counter drugs before talking to your obstetrician or doctor.
Herbal medications
There is this mistaken belief that once something is labelled herbal or natural it has no side effects and is entirely safe. This is not true! Many herbal medications if used during pregnancy can have disastrous effects for the fetus.
Social drugs
In addition to counseling pregnant women regarding use of various prescribed and non-prescribed medications during pregnancy, other substances that are also used by some women during pregnancy should not be overlooked. Alcohol use and smoking can result in severe consequences for the developing fetus.
Illicit drugs and pregnancy
The use of illicit drugs like cocaine and opioids during pregnancy can cause complications and serious problems in the developing fetus and the newborn. Growth of the fetus is likely to be inadequate and premature birth defects are more common. Cocaine crosses the placenta, constricts the blood vessels reducing blood flow to the fetus. The reduced blood and oxygen supply to the fetus slows the growth of bones and intestine. Use of cocaine can also cause complications during pregnancy. Among women who use cocaine throughout pregnancy, 31% have preterm delivery and 15% have premature detachment of placenta. The chances of miscarriage also increase.
Whether use of marijuana during pregnancy can harm the fetus is unclear. The main component of marijuana, tetrahydrocannabinol, can cross the placenta and thus may affect the fetus. However, marijuana does not appear to increase the risk of birth defects or to slow the growth of the fetus. Marijuana does not cause behavioural problems in the newborn unless it is used heavily during pregnancy.
Conclusion
The safety of drug use during pregnancy continues to attract much attention. Sometimes drugs are essential for the health of the pregnant woman and the fetus. In such cases, a woman should talk with her doctor or other healthcare practitioner about the risks and benefits of taking the drug. Doctors and other healthcare providers must continue to update their knowledge on current thinking regarding the use of various drugs during pregnancy and then counsel these pregnant women prior to prescribing any drug to a pregnant or breastfeeding woman.
Ask Your Doctor is a health education column and is not a substitute for medical advice from your physician. The reader should consult his or her physician for specific information concerning specific medical conditions. While all reasonable efforts have been made to ensure that all information presented is accurate, as research and development in the medical field are ongoing, it is possible that new findings may supersede some data presented.
Dr Brett Hodge MB BS DGO MRCOG, is an Obstetrician/Gynaecologist and Family Doctor who has over thirty-two years in clinical practice. Dr Hodge has a medical practice in The Johnson Building in The Valley (Tel: 264 4975828).
