Results
The incidence of preterm birth at <37 weeks was 10/12 (83%) in the VP group and 11/19 (58%) in the control group, and the incidence of preterm birth at <34 weeks was 6/12 (50%) in the VP group and 9/19 (47%) in the control group. The incidence of preterm birth in the two groups was similar, and the difference between the two groups was not statistically significant.