What are the most often cited reasons for women's disproportionate participation in part-time work?

Child-rearing and other family responsibilities are often cited.Generally,women leave work for at least short periods of time to bear children,and often for longer periods to rear their children full-time.This discontinuity in employment is one of the greatest barriers faced by professional and non-professional women alike.Impressions about one's commitment to work,current earnings,lifetime earnings,opportunities for advancement,and future employability are all greatly influenced by interruptions in one's career.