LEARNING THAT SHE is pregnant is a powerful and disconcerting experience for a teen. Because the truth can be so frightening, a girl who notices that her menstrual period is late may for a time fail to acknowledge the significance of this symptom. But pregnancy will not go away with wishful thinking. Pregnant teens must eventually grapple with what is happening to them, but medical and social experts suggest that early acceptance of the new reality is preferable to prolonged denial. They reason that if a girl does not confront the reality of her pregnancy in its earliest months, she could, by inaction, be constrained to carry an unwanted pregnancy to term.

Early acknowledgment of pregnancy is considered equally important for a girl who intends to give birth because she can then begin the medical care and healthy...