“…Earlier first sexual intercourse (FSI) is associated with unprotected intercourse, 1 inconsistent contraceptive use, 2 and multiple partners and with negative social and health outcomes, including partner violence, 3 lower educational attainment, 4,5 unintended pregnancy, teenage parenting, 6 and sexually transmitted infection. 7,8 Definitions of "early" FSI have varied, and include age 15 years and younger 2,4,9 or 16 years and younger, 7,10 or quartiles or tertiles of age at FSI in a study population. 11,12 Previous prospective studies have demonstrated that a range of biological, social, and psychological precursors such as early puberty, childhood adversity, low socioeconomic status, dysfunctional family relationships, absence of a biological father at home, poor school adjustment, adolescent depression, and low self-esteem are associated with earlier age at FSI.…”