RT Journal Article SR Electronic T1 Contraceptive practices and menstrual patterns in women aged 18–50 years awaiting bariatric surgery JF BMJ Sexual & Reproductive Health JO BMJ Sex Reprod Health FD British Medical Journal Publishing Group SP 228 OP 230 DO 10.1136/bmjsrh-2018-200091 VO 44 IS 3 A1 Yitka N H Graham A1 Diana J Mansour A1 Peter K Small A1 Ian S Fraser YR 2018 UL http://jfprhc.bmj.com/content/44/3/228.abstract AB