title: Why do women experience untimed pregnancies? A review of contraceptive failure rates.
authors.affiliation: Department of Obstetrics and Gynaecology, University of Sydney, NSW, Australia. k.black@usyd.edu.au
authors.forename: Kirsten I
authors.initials: KI
authors.lastname: Black
authors.forename: Sunanda
authors.initials: S
authors.lastname: Gupta
authors.forename: Angela
authors.initials: A
authors.lastname: Rassi
authors.forename: Ali
authors.initials: A
authors.lastname: Kubba