Pain management in pregnant patients

Unfortunately, there are not a lot of studies regarding the safety of pain medication in pregnant patients. Acetaminophen is widely used for the treatment of pain and fever, with no high-quality evidence in humans of increased risk of pregnancy loss, congenital anomalies, or neurodevelopmental delay in offspring. The extensive use of acetaminophen by pregnant patients and minimally documented adverse effects makes this medication the pain reliever and antipyretic of choice during pregnancy when short-term drug therapy is indicated. Some experts are concerned that prenatal exposure to acetaminophen might alter fetal development and thereby increase the risks of some neurodevelopmental, reproductive, and urogenital disorders, based on data from experimental and epidemiological research. Acetaminophen is considered safe and is considered by the Society of Obstetricians and Gynecologists of Canada to be the first-line analgesic medication currently available during pregnancy.

On the other hand, NSAIDs should not be routinely used during pregnancy (particularly in the early first and late third trimesters) because of potential fetal effects, although a single dose for refractory postoperative pain in mid-gestation is likely safe.

Regarding opioids, the research is also still a work in progress. For pregnant patients with moderate to severe pain, immediate-release opioids (oxycodone, morphine, hydromorphone, codeine, oxymorphone) are deemed safe especially when alternative pain management options are, or are likely to be, ineffective. Until better data are available, during the first month of embryonic development when neural tube development occurs, shared decision-making involves balancing the small potential increase in incidence of neural tube defects with the need for relief of moderate to severe pain, given the frequent lack of effective alternative analgesics.

In a 2024 meta-analysis, exposure to any opioid use during the first trimester of pregnancy was not associated with a significantly increased risk of major congenital anomalies overall, however, the studies were at high risk of bias. Three epidemiologic studies in humans (one was in the meta-analysis) have also reported an association with neural tube defects, with odds ratios (OR) of 1.7 to 2.9. Other well-designed studies found that prenatal exposure to opioid analgesics had no substantial negative association with scholastic skills in school-aged children and no clinically meaningful increase in neuropsychiatric disorders in offspring. Opioids should only be used when other medications fail to control the pain. In general, short-term, episodic use of opioids such as morphine and fentanyl appear to be safe in pregnancy. However, their use near term is not recommended because of the associated risk of respiratory depression in neonates.

Dr. Froats has recommended the following as a possible way to start the conversation: "There are no medications that are known to be 100% safe in pregnancy. But generally speaking, acetaminophen and opioids are felt to be safe and we recommend them for moderate to severe pain in pregnancy. Uncontrolled pain is not good for the pregnancy either. Ultimately it is your choice but if you were my family in pain, I would have no problem with you having acetaminophen and/or opioids while pregnant."

If after providing education, explanations and evidence to your patient they still refuse treatments that you are offering, they ultimately have the right to do so. As per the Health Care Consent Act, 1996, S.O. 1996, c. 2, Sched. A, patients can choose to accept or refute any treatments being offered to them. The best a paramedic can do for their patient is to provide all of the risks, benefits and education surrounding accepting or refusing treatments.