The Effects of dental scaling on adverse birth outcome : a randomized trial in Karachi, Pakistan

Date of Award


Document Type


Degree Name

Master of Science in Epidemiology & Biostatistics (MSc Epidemiology & Biostats)


Community Health Sciences


Approximately two-thirds of pregnant Pakistani women suffer from periodontal disease which is a common inflammatory disease of the soft tissues surrounding the tooth. Offenbacher in 1996 demonstrated that periodontitis among pregnant women is significantly associated with preterm birth and low birth weight. Pakistan has a high prevalence of these adverse birth outcomes therefore; identifying an intervention is of prime importance and may have social and economic benefits. Methods: One hundred and forty two women were recruited from two private obstetric clinics in Karachi. They were randomized to receive dental scaling and oral hygiene instructions by 28 weeks of gestation (intervention) and oral hygiene instructions only (control). All the controls received scaling after cessation of pregnancy. A qualified and trained dentist conducted the oral examination for the plaque index, gingival bleeding index and the periodontal pocketing. A blinded observer recorded the measures at the time of birth for a composite outcome comprising of either preterm birth (<37weeks of gestation), low birth weight (<2500g birth weight) or still birth. Results: During the interim analysis there were a total of 8 (22.22%) adverse outcomes recorded in the intervention group and 10 (24.39%) adverse outcomes recorded in the control group. The mean gestational age in intervention group was 37.68 (SD 2.23) weeks and in the control group was 37.19 (SD 2.38) weeks. The mean birth weight in the intervention arm was 2893.61 (556.71) grams and the control arm was 2712.5 (487.89) grams. The difference between the two groups was statistically insignificant at p=0.823. Conclusion: There was a reduction in the number of adverse birth events in the intervention group receiving dental scaling and oral hygiene instructions by 28 weeks of gestation as compared to the group which received oral hygiene instructions only. The results were similar to what have been observed in similar trials in developing countries.

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