The objective of this study was to determine whether pregnancies with false positive MMST are associated with increased pregnancy complications. The pregnancy outcomes of 211 pregnancies with false positive MMST were compared to a control group of 300 patients with low-risk MMST results. Both groups were from a low-risk population, matched for age and parity and gestation confirmed with ultrasonography. Adverse outcomes (preterm delivery < 37 weeks gestation, low-birth weight (LBW) < 2500 gm, fetal loss > 20 weeks gestation, congenital infections and abnormalities, APGAR scores < 7 at 5 minutes and operative deliveries). Chi-square analysis and Fisher's tests were used for comparison as appropriate. Preterm delivery 12 of 211 (5.6%) versus 14 of 300 (4.6%), odds ratio 1.2 CI (0.56-2.7); LBW 5 of 211 (2.3%) versus 5 of 300 (1.6%) OR 1.5 CI (0.43-5.3); Instrumental delivery 20 of 211 (9.4%) versus 22 of 300 (7.3%) OR 0.85 CI (0.46-1.6); and caesarean section 45 of 211 (21.3%) versus 51 of 300 (17%) OR 1.3 CI (0.84-2.1); APGAR scores < 7 at 5 minutes 12 of 211 (5.6%) versus 17 of 300 (5.6%) OR 0.88 CI (0.39-2.0). No fetal loss or congenital infections occurred. There was 1 case of rudimentary extra-digit in the false positive group.