Background Pregnant women demonstrate increases in gingivitis despite similar plaque levels to non-pregnant counterparts. Aim To evaluate an intensive protocol aimed at reducing gingivitis in pregnant women and provide pilot data for large-scale randomized controlled trials investigating oral hygiene measures to reduce pregnancy gingivitis and alter maternity outcomes. Materials and Methods One hundred and twenty participants between 16 and 24 weeks gestation with Gingival Index (GI) scores ≥2 at ≥50% of tooth sites were enrolled. Plaque index (PI), gingival inflammation (GI), probing depth (PD), and clinical attachment levels (CAL) were recorded at baseline and 8 weeks. Dental prophylaxis was performed at baseline and oral hygiene instructions at baseline, 4 and 8 weeks. Pregnancy outcomes were recorded at parturition. Mixed-model analysis of variance was used to compare clinical measurements at baseline and 8 weeks. Results Statistically significant reductions in PI, GI, PD, and CAL occurred over the study period. Mean whole mouth PI and GI scores decreased approximately 50% and the percentage of sites with PI and GI ≥2 decreased from 40% to 17% and 53% to 21.8%, respectively. Mean decreases in whole mouth PD and CAL of 0.45 and 0.24 mm, respectively, were seen. Conclusions Intensive oral hygiene regimen decreased gingivitis in pregnant patients. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.