Summary of key associations in mother and infant groups according to maternal single dose nevirapine.

aS: significant association (PPbSA: Same association i.e. the trend or significant association is going in the same direction as non-stratified group comparison.-: Not applicable (i.e. not significant or no trend in stratified groups).aS：显著关联；PPbSA：相同关联，即分层组的趋势或显著关联与非分层组比较的方向一致；-：无适用情形，即分层组中不存在显著关联或无相关趋势。