Drugs in pregnancy

Drug use during pregnancy can have temporary or permanent effects on the fetus. Any drug that acts during embryonic or fetal development to produce a permanent alteration of form or function is known as a teratogen. Drugs may refer to both pharmaceutical drug and recreational drugs.

Pharmaceutical drugs

The apprehension is not necessarily data driven and is a cautionary response to the lack of clinical studies in pregnant women. The indication is a trade-off between the adverse effects of the drug, the risks associated with intercurrent diseases and pregnancy complications, and the efficacy of the drug to prevent or ameliorate such risks. In some cases, the use of drugs in pregnancy carries benefits that outweigh the risks. For example, high fever is harmful for the fetus in the early months, thus the use of paracetamol (acetaminophen) is generally associated with lower risk than the fever itself. Similarly, diabetes mellitus during pregnancy may need intensive therapy with insulin to prevent complications to mother and baby. Pain management for the mother is another 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 never take a dose higher than 100 mg.

Pregnancy categories

Main article: Pregnancy category

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 (FDA). 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 categorisations 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(Australian Government, 2014).

Anticonvulsants

Valproic acid, 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.

Alcohol

See also: Fetal alcohol spectrum disorders

Medical organizations strongly discourage drinking alcohol during pregnancy. Alcohol passes easily from the mother's bloodstream through the placenta and into the bloodstream of the fetus, which interferes with brain and organ development. Alcohol can affect the fetus at any stage during pregnancy, but the level of risk depends on the amount and frequency of alcohol consumed. Regular heavy drinking and binge drinking (four or more drinks on any one occasion) pose the greatest risk for harm, but lesser amounts can cause problems as well. There is no known safe amount or safe time to drink during pregnancy.

Prenatal alcohol exposure can lead to fetal alcohol spectrum disorders (FASDs). The most severe form of FASD is fetal alcohol syndrome (FAS). Problems associated with FASD include facial anomalies, low birth weight, stunted growth, small head size, 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.

Recreational drugs

Recreational drug use during pregnancy can cause various pregnancy complications.

Cannabis

Main article: Cannabis in pregnancy

Cannabis in pregnancy is the subject of various scientific studies, usually regarding whether it has effects on the child later in life.

File:Cannabis sativa00.jpg

Recreational drug; cannabis. Plant having a significant effect on prenatal birth.

Effects found by Fergusson, D. M., Horwood, L. J., & Northstone, K. (2002) where that cannabis had a negative effect on babies. They were found to weigh significantly less, as well having shorter birth lengths, and had smaller head circumferences than babies who were not exposed to prenatal cannabis.

Smoking

Main article: Smoking and pregnancy

A number of studies have shown that tobacco use is a significant factor in miscarriages among pregnant smokers, and that it contributes to a number of other threats to the health of the fetus. Smoking and pregnancy, combined, cause twice the risk of premature rupture of membranes, placental abruption and placenta previa. Also, it causes 30% higher odds of the baby being born prematurely.

Cocaine

Prenatal cocaine exposure is associated with, for example, premature birth, birth defects and attention deficit disorder.

A recent study on cocaine in Prenatal Drug Exposure(2008) explores how the differences between children who were exposed to drugs prenatal and those with non-drug prenatal exposure differ at the age of five.

Many of the side effects from the children who were exposed to the recreational drug being cocaine had side effects including the following; lack in school readiness, slower impulse control and lack in visual attention.

Others

• Prenatal methamphetamine exposure can cause premature birth and congenital abnormalities. Other investigations have revealed short-term neonatal outcomes to include small deficits in infant neurobehavioral function and growth restriction when compared to control infants. Also, prenatal methamphetamine use is believed to have long-term effects in terms of brain development, which may last for many years.
• Marijuana can cause low birth weight, tremors, poor eyesight, late start of breathing, and a hole in the heart. In the first six months of life babies who have been exposed to marijuana have a higher chance of having breathing problems such as asthma, chest infections, and wheezing. By the age of three or four the child might be fearful, reckless, inattentive, restless, irresponsible, and may have poor memory, verbal, and reasoning ability; at age ten these problems can continue along with depression, anxiety, reading and spelling problems.

By pregnancy stage

Pregnancy and fetal development progress through various changes. The period of one week from fertilisation to implantation of the fertilized egg is called the preimplantation period. This is an 'all or none' period, .i.e. an insult can either cause death or complete recovery can occur. The period from the eighth day to the end of eighth week is the period of organogenesis during which the organs are formed in the fetus. This is the most crucial time with regards to 'structural malformations' and concern over teratogenicity of drugs. From the third month to the end of nine months is the period of fetal maturation. Intake of drugs during this period may modify the 'function' of the fetal organs rather than causing gross structural malformations in the fetus; for example, aminoglycosides can affect the functioning of the kidneys as well as the hearing mechanism. Another example is when cocaine crosses through the placenta, this directly influences the fetus and its chances to fully develop are slim because it has a negative effect on the brain.