How can a 36-week pregnant woman manage symptoms of severe lower back pain, heartburn, difficulty breathing when lying down, frequent urination, constipation, and pelvic pressure?

Management of Late-Pregnancy Symptoms at 36 Weeks

For this 36-week pregnant woman, implement a stepwise approach prioritizing non-pharmacological interventions first, followed by safe pharmacological options for refractory symptoms, with specific attention to positional modifications for respiratory symptoms, dietary and lifestyle changes for heartburn, and conservative measures for musculoskeletal complaints.

Respiratory Symptoms (Dyspnea When Supine)

Anatomical Basis

• The uterine fundus at 36 weeks reaches the xiphoid process, causing superior displacement of the diaphragm by approximately 4 cm, reducing functional residual capacity and limiting diaphragmatic excursion 1
• The widened subcostal angle (105° in this patient) and increased anteroposterior chest diameter represent compensatory mechanisms that are insufficient when supine 1

Management Strategy

• Sleep in a semi-recumbent position with multiple pillows elevating the upper body at 30-45 degrees to reduce upward pressure on the diaphragm and improve lung expansion 1
• Avoid the supine horizontal position, especially during the third trimester, as the gravid uterus compresses the inferior vena cava, decreasing venous return and cardiac output 1
• Left lateral decubitus position is optimal when lying down, as it minimizes vena cava compression while allowing better diaphragmatic movement 1
• Reassure the patient that these symptoms typically improve after 36-37 weeks when the fetal head descends into the pelvis ("lightening"), reducing fundal height 1

Heartburn Management

First-Line: Dietary and Lifestyle Modifications

• Consume small, frequent meals (5-6 per day) rather than 3 large meals to reduce gastric distension and lower esophageal sphincter pressure 2, 3
• Avoid spicy, fatty, acidic, and fried foods that exacerbate reflux 2, 3
• Continue sleeping propped up on multiple pillows (already doing this correctly) to prevent nocturnal reflux 1, 2
• Avoid eating within 2-3 hours of bedtime 2

Pharmacological Options for Refractory Heartburn

• If dietary modifications fail, antacids (calcium carbonate or magnesium-based) are safe first-line pharmacological options 1, 2
• The American Gastroenterological Association reports moderate-quality evidence for pharmaceutical treatments showing complete heartburn relief (RR 1.85) compared to placebo 2
• H2-receptor antagonists and proton pump inhibitors can be considered for severe, refractory symptoms under obstetric guidance 1

Common Pitfall: The physiological basis is progesterone-induced relaxation of the lower esophageal sphincter, not just mechanical compression, so positional changes alone may be insufficient 2

Lower Back Pain and Pelvic Pressure

Anatomical Contributors

• Pronounced lumbar lordosis and anterior pelvic tilt (noted on exam) result from the gravid uterus shifting the center of gravity anteriorly 1
• Positive Patrick's test and sacroiliac joint tenderness indicate pelvic joint laxity from relaxin hormone effects 1
• The widened gait pattern is compensatory for the altered center of gravity 1

Conservative Management

• Maintain neutral lumbar spine positioning during daily activities to optimize bladder control and prevent worsening back problems 1
• Avoid prolonged standing or walking; alternate positions frequently 1
• Pelvic support garments or maternity belts can reduce sacroiliac joint stress and improve stability 1
• Warm compresses to the lower back and gentle stretching exercises may provide symptomatic relief 1
• Physical therapy focusing on pelvic floor exercises and core stabilization can be beneficial 1

Important Consideration: The association between back pain and urinary symptoms is well-established (OR 2.3-2.5), so addressing pelvic floor dysfunction may help both conditions 4, 5, 6

Frequent Urination

Physiological Basis

• At 36 weeks, the fetal presenting part (vertex in this case) compresses the bladder, reducing functional capacity 1
• This is a normal anatomical consequence and typically improves after delivery 1

Management

• Perform timed voiding every 2-3 hours during the day to prevent bladder overdistension 7
• Reduce fluid intake 2-3 hours before bedtime to minimize nocturia, while maintaining adequate daytime hydration 7
• Avoid bladder irritants including caffeine, carbonated beverages, and artificial sweeteners 7
• Pelvic floor muscle exercises (Kegels) can improve urinary control and prepare for delivery 1, 7

Constipation

Evidence-Based Treatment Algorithm

Step 1: Dietary Fiber

• Increase dietary fiber intake to approximately 30 g/day through fruits, vegetables, whole grains, and legumes 1
• Ensure adequate fluid intake (8-10 glasses of water daily) to soften stools 1

Step 2: Bulk-Forming Agents

• Psyllium husk or methylcellulose are safe first-line pharmacological options due to lack of systemic absorption 1
• Soluble fiber like psyllium improves both stool viscosity and transit time 1

Step 3: Osmotic Laxatives

• Polyethylene glycol or lactulose can be safely administered for refractory constipation 1
• Note that excessive fiber and lactulose may cause maternal bloating 1

Avoid: Stimulant laxatives should be avoided due to conflicting safety data during pregnancy 1

Behavioral Modifications

• Allow ample time for bowel movements without straining 1
• Use relaxation techniques during defecation 1
• Establish a regular bowel routine, ideally after meals when gastrocolic reflex is strongest 1

Nausea Management (If Present)

Although not the primary complaint, given the heartburn severity:

• Vitamin B6 (pyridoxine) 10-25 mg every 8 hours (30-75 mg total daily) is safe and effective for pregnancy-related nausea 8, 3
• Ginger 250 mg four times daily may provide additional benefit 3
• Early treatment prevents progression to hyperemesis gravidarum (0.3-2% of pregnancies) 1, 8, 3

Red Flags Requiring Immediate Evaluation

• Sudden severe headache, visual changes, or epigastric pain (preeclampsia signs) 1
• Decreased fetal movement 1
• Vaginal bleeding or fluid leakage 1
• Regular contractions before 37 weeks (preterm labor) 1
• Severe, unrelenting abdominal pain 1

Multidisciplinary Coordination

This patient should continue routine prenatal care with her obstetrician, with consideration for:

• Physical therapy referral for musculoskeletal symptoms 1
• Nutritionist consultation if dietary modifications are challenging to implement 1
• Reassurance that most symptoms will improve significantly after delivery and fetal descent into the pelvis around 37-38 weeks 1