RT Journal Article SR Electronic T1 Increased body mass index and reduced efficacy of oral emergency contraception: how many women might be affected? JF Journal of Family Planning and Reproductive Health Care JO J Fam Plann Reprod Health Care FD British Medical Journal Publishing Group SP 234 OP 235 DO 10.1136/jfprhc-2016-101464 VO 42 IS 3 A1 Sarah C Woodhall A1 Catherine M Lowndes A1 Rachel Craig A1 Jennifer S Mindell A1 Dame Jane Anderson A1 Kate A Guthrie A1 Dame Anne M Johnson A1 Anthony Nardone YR 2016 UL http://jfprhc.bmj.com/content/42/3/234.abstract AB