# Unilateral Pulmonary Edema Associated With Prolonged Lateral Decubitus Positioning During Tocolytic Therapy in Pregnancy: A Case Report

**Authors:** Kei Takumi, Toshihito Mihara, Mao Kinoshita

PMC · DOI: 10.7759/cureus.103398 · 2026-02-11

## TL;DR

A pregnant woman developed one-sided lung fluid likely due to drug use and lying on her side for too long, highlighting the need for careful positioning during treatment.

## Contribution

Identifies a rare case linking unilateral pulmonary edema in pregnancy to prolonged lateral positioning and tocolytic therapy.

## Key findings

- Unilateral pulmonary edema in a pregnant woman was associated with prolonged left lateral decubitus positioning.
- Drug-induced pulmonary edema combined with positioning may cause atypical radiologic findings.
- Early recognition of positional effects can aid in timely diagnosis and treatment.

## Abstract

Peripartum pulmonary edema is rare but potentially life-threatening for both the mother and fetus. Unilateral pulmonary edema is particularly uncommon and can mimic pneumonia, delaying appropriate diagnosis because of atypical radiologic findings. A 28-year-old pregnant woman (G3P1) hospitalized for threatened preterm labor received ritodrine hydrochloride and magnesium sulfate. At gestational week 25, she suddenly developed chest pain, dyspnea, and hypoxemia. Chest X-ray revealed unilateral, left-sided pulmonary infiltrates. Cardiac evaluation showed no evidence of cardiogenic pulmonary edema, and infection was excluded, suggesting drug-induced pulmonary edema. Tocolytic agents were discontinued; however, respiratory failure necessitated emergency cesarean delivery. Postoperatively, pulmonary edema rapidly improved with intensive care. A detailed history revealed prolonged left lateral decubitus positioning before symptom onset. Drug-induced pulmonary edema combined with prolonged lateral positioning may predispose pregnant women to unilateral pulmonary edema. Awareness of positional effects during tocolytic therapy is important for early diagnosis.

## Linked entities

- **Chemicals:** ritodrine hydrochloride (PubChem CID 3040551), magnesium sulfate (PubChem CID 24083)
- **Diseases:** pulmonary edema (MONDO:0006932)

## Full-text entities

- **Diseases:** chest pain (MESH:D002637), Decubitus (MESH:D003668), hypoxemia (MESH:D000860), Pulmonary Edema (MESH:D011654), respiratory failure (MESH:D012131), preterm labor (MESH:D007752), infection (MESH:D007239), pneumonia (MESH:D011014), pulmonary infiltrates (MESH:D017254), dyspnea (MESH:D004417)
- **Chemicals:** magnesium sulfate (MESH:D008278), ritodrine hydrochloride (MESH:D012312)
- **Species:** Homo sapiens (human, species) [taxon 9606]

## Figures

3 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12983116/full.md

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Source: https://tomesphere.com/paper/PMC12983116