Among women without prior sdNVP exposure , 8 of 39 ( 21 % ) with NVP-resistant variants experienced VF or death vs 31 of 180 ( 17 % ) without such variants ( P = .65 ) ; this compares with 21 of 51 ( 41 % ) vs 9 of 63 ( 14 % ) among women with prior exposure ( P = .001 ) .