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Science in the News

Clinical Trial Supports Safety of Providing Dental Care to Pregnant Patients

August 12, 2008


In a study released this summer, the provision of periodontal therapy and essential dental treatment to expectant mothers at 13 to 21 weeks’ gestation (early-to-mid second trimester) was not associated with increased risk of adverse pregnancy outcomes or other serious adverse events. The study, published in the June 2008 issue of The Journal of the American Dental Association,1 received online news coverage from ScienceDaily,2 MedicalNewsToday,3 and other outlets.

The research team, led by Dr. Bryan Michalowicz of the University of Minnesota, analyzed data from the Obstetrics and Periodontal Therapy (OPT) trial, a multi-center clinical study funded by the National Institute for Dental and Craniofacial Research to evaluate whether non-surgical periodontal therapy in pregnant women reduced risks of preterm delivery (study available in November 2, 2006 New England Journal of Medicine).4 The participants included over 800 pregnant women with periodontitis, most of whom were black and Hispanic (45.2% and 42.5%, respectively), and all considered at high risk for preterm delivery.

The researchers assigned the women into two groups: a periodontal treatment group that received scaling and root planing before 21 weeks’ gestation, including topical or local anesthetics when needed; and a control group that received scaling and root planing within 3 months after delivery. Dentists evaluated the participants for essential dental treatment needs, provided periodic periodontal examinations, and treated moderate-to-severe caries and fractured or abscessed teeth before the participants reached their 21st week of pregnancy. Obstetric nurses also reviewed medical records during the study to monitor participants for serious adverse events, including: pregnancies that ended in a nonlive birth, spontaneous abortions and stillbirths; and other adverse events that did not result in pregnancy termination (e.g., fetal or congenital anomalies, hospitalizations for more than 24 hours due to labor pains). After completion of the trial, the researchers reviewed data across all patient groups to identify associations between adverse pregnancy outcomes and the provision of essential dental care and periodontal therapy (before 21 weeks or after delivery).

The study identified 483 expectant mothers who required dental treatment, or nearly 59 percent of the participants, and 351 completed all recommended treatment. After careful accumulation of data, regardless of how the study participants were grouped by dental or periodontal treatment, the OPT researchers found that providing periodontal treatment and essential dental care between the 13th and 21st weeks of pregnancy did not increase the risk of any adverse outcome evaluated. The study also reported no adverse effects from the use of topical or local anesthetics in women who received dental treatment at 13 to 21 weeks’ gestation.

Lastly, the study calls attention to the suboptimal use of dental services by pregnant women, and practitioner uncertainty about which dental procedures are appropriate for pregnant patients. According to the authors, surveys “suggest that only about one-quarter to one-half of women receive any dental care, including prophylaxes, during their pregnancies.” While acknowledging several study limitations (e.g., limited generalizability to non-minority populations or women without periodontitis), the authors note that the OPT trial findings can allay the concerns of patients and clinicians by offering “evidence that dental care providers can safely meet the preventive and routine treatment needs of their pregnant patients.” The OPT researchers also recommend additional large clinical trials to provide further confirmation of the safety of dental treatment during pregnancy.

As addressed in the ADA monograph Women’s Oral Health Issues, dental evaluations of pregnant patients should begin with a comprehensive medical history and consultation with the patient’s physician or obstetrician as appropriate. The ADA monograph also recommends that elective dental care of pregnant patients should be timed to occur during the second trimester and first half of the third trimester. For more information on pregnancy and oral health care, visit for:


1. Michalowicz BS, DiAngelis AJ, Novak MJ, et al. Examining the safety of dental treatment in pregnant women. JADA 2008;139(6):685-95.

2. Essential dental treatment safe for pregnant women, says new study. ScienceDaily. June 16, 2008.

3. Essential dental treatment safe for pregnant women. MedicalNewsToday, June 11, 2008. 

4. Michalowicz BS, Hodges JS, DiAngelis AJ, et al. Treatment of periodontal disease and the risk of preterm birth. N Engl J Med 2006; 355(18):1885–1894.

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Science in the News is a service by the American Dental Association (ADA) to its members to present current information about science topics in the news. The ADA is a professional association of dentists committed to the public's oral health, ethics, science and professional advancement; leading a unified profession through initiatives in advocacy, education, research and the development of standards. As a science-based organization, the ADA's evaluation of the scientific evidence may change as more information becomes available. Your thoughts would be greatly appreciated.

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