Pregnancy and lactation have no long-term deleterious effect on measures of bone mineral in healthy women: a twin study.

Background: The long-term effects of pregnancy and lactation on measures of bone mineral in women remain unclear.

Objective: We studied whether pregnancy or lactation has deleterious long-term effects on bone mineral in healthy women.

Design: We measured bone mineral density (BMD; g/cm(2)) in women aged > or = 18 y.