There was a significant increase in the number of physician interventions (additional testing of mother or baby; extra office, emergency, or labor and delivery unit visits; and especially extra hospitalizations) but no significant difference in perinatal outcome (illness in mother or baby) when women at high-risk for preterm labor on home uterine activity monitoring services had scheduled twice-a-day review (BID review) of the home uterine activity monitoring data they had collected versus once-a-day review (OD review).