Many studies have evaluated the association between periodontal disease and premature, low birth-weight babies, but none have demonstrated a direct cause and effect. Such a study would be lengthy, expensive and difficult to complete. One barrier to undertaking this study is the random assignment of pregnant women with periodontal disease to the no-treatment control group. Ethics committees find this unacceptable.

Researchers at Feira de Santana State University, in Bahia, Brazil devised a study design to avoid assigning a control group. The group of pregnant women with untreated periodontal disease was identified after giving birth. Seven days after giving birth, a periodontal examination was provided and those with periodontal disease were recruited as controls. Birth weights of their babies were recorded.

A group of periodontally healthy pregnant mothers and a group of pregnant mothers with periodontal disease were the test groups. Those with periodontal disease were treated with SRP and seen monthly during their pregnancy for follow-up care. The healthy subjects were also seen monthly for prophylaxis to maintain oral health.

The rate of low birth-weight was 11 percent in both the treated periodontal group and the healthy group. It was twice as high in the untreated periodontal group, although this group also had more risk factors for pre-term, low birthweight deliveries.

Although this study does not show benefit from periodontal therapy in preventing pre-term, low birth-weight babies, it does confirm that periodontal therapy is safe for pregnant women.

Clinical Implications: This is additional evidence that treating pregnant women for periodontal disease during pregnancy is safe.

1.Gomes-Filho, I., Cruz, S., Costa, M., Passos, J., Cerqueira, E., Sampaio, F., Pereira, E., Miranda, L.: Periodontal Therapy and Low Birth Weight: Preliminary Results from an Alternative Methodologic Strategy. J Perio 81:1725-1733, 2010.