# Oral health care during pregnancy to prevent preterm birth and low birth weight: study protocol for a randomized controlled trial

## TL;DR

This study tests if treating periodontal disease with scaling, root planing, and chlorhexidine mouthwash during pregnancy can reduce preterm births and low birth weight.

## Contribution

This is the first RCT to evaluate the combined use of SRP and CHG mouthwash for improving birth outcomes in pregnant women with periodontal disease.

## Key findings

- The study will assess if the combined intervention reduces preterm birth rates.
- It will also evaluate effects on birth weight and maternal oral health quality of life.
- Results may inform integrating oral health care into maternal health strategies in low-resource settings.

## Abstract

Periodontal disease during pregnancy has been associated with an increased risk of preterm birth (PTB) and low birth weight (LBW). However, most previous interventional studies have reported that scaling and root planing (SRP), a form of basic periodontal treatment, is insufficient to effectively prevent PTB and LBW. Recent systematic reviews and meta-analyses suggest that combining SRP with routine use of chlorhexidine gluconate (CHG) mouthwash may reduce the risk of these adverse birth outcomes by approximately half. This study will be among the first randomized controlled trials (RCTs) to evaluate the potential synergistic effects of this combined approach on improving birth outcomes.

This multi-center, three-arm RCT will be conducted at two hospitals in Dhaka and Bogura, Bangladesh, between April 2025 and September 2026. A total of 480 pregnant women less than 20 weeks’ gestation attending antenatal checkups will be recruited. Participants diagnosed with periodontal disease will be randomly assigned to either an intervention group or a positive control group. Participants without periodontal disease will be assigned to a negative control group. The intervention consists of SRP combined with continued use of CHG mouthwash throughout pregnancy. The primary outcome will be the rate of PTB. Secondary outcomes include the birth weight of the newborn baby, maternal periodontal status, and oral health-related quality of life (OHRQoL). Effectiveness will be assessed by comparing outcomes across the study groups.

The oral health intervention is expected to improve both birth outcomes and maternal oral health. Demonstrating its effectiveness in a real-world setting may support the integration of oral health care into broader maternal, neonatal, and child health strategies, particularly in resource-limited settings.

UMIN Clinical Trials Registry. UMIN000057519. Registered on April 4, 2025. https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000065719.

The online version contains supplementary material available at 10.1186/s13063-025-09355-y.