New research has found that women are on average no more likely to have multiple sexual partners in a single month after they are provided no-cost access to birth control methods than they were before. And while women reported a slight uptick in their reported monthly sexual encounters a year after getting free contraceptives, the new study says the resulting frequency of sexual activity fell within expected boundaries for women of childbearing age.

In a prospective cohort study called the Contraceptive Choice Project, 9,256 women and teenage girls in and around St. Louis were provided reversible birth control methods free of charge for a year. The subjects, ages 14 to 45, were asked to complete a survey upon recruitment, before they were prescribed and dispensed the birth control method of their choice, and at six and 12 months after their first visit.

The survey primarily aimed to measure two factors most closely tied to unintended pregnancies and sexually transmitted diseases: having multiple sexual partners and frequency of sex. Among the 7,751 participants who completed the surveys, researchers from Washington University in fact observed a statistically significant decrease in the number of sexual partners participants reported having had in the 30 days preceding. […]