Researchers at Case Western Reserve University have determined frequent gingival bleeding due to periodontal infection during pregnancy can lead to oral bacteria entering the mother's bloodstream and invading the uterus, leading to pregnancy complications. Current studies of single or multiple treatments have either been ineffective or too costly for low-resource settings. Therefore, researchers are proposing a pilot randomized control study to test the efficacy of daily antibacterial mouth rinse on pregnancy and birth outcome. There will be 400 pregnant women in the study from Ning-Qiang County in Shaanxi Province from China. The mouth rinse method is potentially a low cost and effective way to reduce preterm low birth weight due to pregnancy complications.