Residency · Residency · Family Medicine
Common Pregnancy Complaints and Safe Medication Use
Introduction
Pregnancy is accompanied by a range of physiological changes that produce symptoms frequently encountered in primary care. Family physicians must be prepared to manage these complaints effectively while ensuring medication safety for both mother and fetus. Understanding the transition from the former FDA pregnancy risk categories to the Pregnancy and Lactation Labeling Rule (PLLR) is essential for informed prescribing.
Nausea and Vomiting of Pregnancy
Epidemiology and Pathophysiology
Nausea and vomiting affect 70 to 80% of pregnancies, typically from weeks 6 through 16. The symptoms are driven by rising human chorionic gonadotropin (hCG) and estrogen levels. Hyperemesis gravidarum (HG), the severe end of the spectrum, occurs in 0.3 to 3% of pregnancies and requires aggressive management.
Management
First-line management includes dietary modifications such as small, frequent meals, bland foods, and ginger supplements. Pyridoxine (vitamin B6) at 10 to 25 mg three times daily, alone or combined with doxylamine 12.5 mg, is the standard pharmacologic first step. Ondansetron 4 mg may be used when first-line agents fail, though data on first-trimester safety remain debated. IV fluids and hospitalization are indicated for hyperemesis gravidarum with ketonuria or weight loss exceeding 5%.
Heartburn and Gastroesophageal Reflux
Heartburn affects up to 80% of pregnant patients by the third trimester, caused by progesterone-mediated lower esophageal sphincter relaxation and mechanical compression from the growing uterus. Safe treatment options include calcium carbonate antacids, H2 blockers such as ranitidine, and PPIs such as omeprazole if symptoms are refractory. Sodium bicarbonate should be avoided in large doses due to the risk of metabolic alkalosis.
Musculoskeletal Complaints
Low Back Pain
Low back pain has a prevalence of 50 to 70% during pregnancy and is related to the anterior shift in center of gravity and ligamentous laxity from relaxin. Management includes physical therapy, acetaminophen, pelvic support belts, and aquatic exercise. NSAIDs are contraindicated after 20 weeks due to the risk of premature ductus arteriosus closure and oligohydramnios.
Round Ligament Pain
Round ligament pain presents as sharp, unilateral lower abdominal or groin pain, typically in the second trimester. Reassurance and positional changes are the primary approach, with acetaminophen as needed for discomfort.
Constipation and Hemorrhoids
Progesterone slows GI motility, and iron supplementation commonly worsens symptoms. First-line management includes increased fiber intake of 25 to 30 g per day, adequate hydration, and exercise. Safe laxatives include polyethylene glycol (PEG), docusate sodium, and psyllium. Hemorrhoids are managed with topical treatments such as witch hazel, sitz baths, and avoidance of prolonged straining.
Headaches in Pregnancy
Tension-type headaches are the most common variety, and migraines often improve after the first trimester. Acetaminophen is first-line for analgesia. Medications to avoid include high-dose aspirin, NSAIDs (especially in the third trimester), ergotamines, and triptans (which have limited safety data). Red flags requiring urgent evaluation include new-onset headache after 20 weeks, which may signal preeclampsia, focal neurological deficits, and thunderclap onset.
Urinary Tract Infections
Asymptomatic bacteriuria should be screened for and treated in pregnancy, unlike in the general population where it does not require treatment. Safe antibiotics include nitrofurantoin (avoiding use at term), cephalexin, and amoxicillin-clavulanate. Fluoroquinolones and tetracyclines should be avoided throughout pregnancy. Untreated UTIs increase the risk of pyelonephritis and preterm labor.
Safe Medication Principles
General Framework
The PLLR, implemented in 2015, replaced the letter categories (A, B, C, D, X) with narrative summaries of risk. The risk-benefit calculation should always weigh maternal benefit against fetal risk, recognizing that untreated maternal disease can itself harm the fetus. The lowest effective dose for the shortest duration is the guiding principle. Resources such as LactMed, MotherToBaby, and Reprotox provide up-to-date safety data.
Commonly Used Safe Medications
| Symptom | Safe Options | Avoid |
|---|---|---|
| Pain | Acetaminophen | NSAIDs (after 20 wks), opioids (chronic) |
| Allergies | Loratadine, cetirizine | First-gen antihistamines (caution) |
| Cough | Dextromethorphan, guaifenesin | Codeine (third trimester) |
| Depression | Sertraline, fluoxetine | Paroxetine (cardiac defects) |
Key Clinical Pearls
Pyridoxine-doxylamine is the only FDA-approved combination specifically for nausea and vomiting of pregnancy. NSAIDs should be avoided after 20 weeks of gestation, and acetaminophen remains the analgesic of choice throughout pregnancy. Asymptomatic bacteriuria should always be screened for and treated in pregnancy, as this is a unique indication for treatment that does not apply to the general population. New-onset headache after 20 weeks warrants immediate blood pressure measurement and preeclampsia workup. When in doubt about medication safety, MotherToBaby (Organization of Teratology Information Specialists) is an authoritative resource.
References
- American College of Obstetricians and Gynecologists. (2018). ACOG Practice Bulletin No. 189: Nausea and Vomiting of Pregnancy. Obstetrics & Gynecology, 131(1), e15-e30.
- Briggs, G. G., Freeman, R. K., & Towers, C. V. (2022). Drugs in Pregnancy and Lactation (12th ed.). Wolters Kluwer.
- Saldanha, I. J., et al. (2022). Management of nausea and vomiting in pregnancy: A systematic review. JAMA, 327(17), 1691-1702.
- FDA. (2014). Pregnancy and Lactation Labeling Rule (PLLR) Final Rule. U.S. Food and Drug Administration.