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

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

1. American College of Obstetricians and Gynecologists. (2018). ACOG Practice Bulletin No. 189: Nausea and Vomiting of Pregnancy. Obstetrics & Gynecology, 131(1), e15-e30.
2. Briggs, G. G., Freeman, R. K., & Towers, C. V. (2022). Drugs in Pregnancy and Lactation (12th ed.). Wolters Kluwer.
3. Saldanha, I. J., et al. (2022). Management of nausea and vomiting in pregnancy: A systematic review. JAMA, 327(17), 1691-1702.
4. FDA. (2014). Pregnancy and Lactation Labeling Rule (PLLR) Final Rule. U.S. Food and Drug Administration.

For the intern

When called at 3am about pregnancy complaints, first rule out emergencies: new headache after 20 weeks needs immediate blood pressure check for preeclampsia, and severe abdominal pain requires assessment for ectopic pregnancy, appendicitis, or placental abruption. For routine complaints like nausea, heartburn, or back pain, reassure and recommend non-pharmacologic measures, then prescribe acetaminophen or antacids as appropriate—these can wait until morning rounds for detailed counseling. Always verify gestational age before prescribing anything, as some medications (like NSAIDs) become contraindicated after 20 weeks.

Common pitfalls

• Prescribing NSAIDs after 20 weeks gestation: This can cause premature ductus arteriosus closure and oligohydramnios. Acetaminophen is the analgesic of choice throughout pregnancy.

• Missing preeclampsia presentation as "just a headache": Any new-onset headache after 20 weeks requires blood pressure measurement and consideration of preeclampsia workup with urinalysis and labs.

• Failing to treat asymptomatic bacteriuria: Unlike non-pregnant patients, pregnant women should be screened and treated for asymptomatic bacteriuria due to increased pyelonephritis and preterm labor risk.

• Using outdated FDA letter categories (A, B, C, D, X): These were replaced by the PLLR in 2015. Instead, use resources like MotherToBaby or LactMed for current evidence-based recommendations on specific medications.

Make it stick

You're a rotating intern on your family medicine obstetrics block. Your senior resident calls you to staff a gravida 2 para 1 at 30 weeks gestation who came to the emergency department with a new, severe headache. She reports no vision changes or abdominal pain. Recalling your lecture, you immediately ask the nurse to check her blood pressure and order a urine dipstick for protein. Her blood pressure is 165/105 mmHg, and her urine dipstick is 2+ for protein. You promptly alert your senior resident, who commends your quick thinking. This patient's headache wasn't "just a headache"; it was a sign of preeclampsia.

If you remember one thing

New-onset headache after 20 weeks gestation warrants an immediate blood pressure check and evaluation for preeclampsia. Always prioritize ruling out serious conditions in pregnant patients, even for common complaints.

Read this lecture as Markdown