The investigators will follow the Consolidated Standards of Reporting Trials (CONSORT) guidelines wherever appropriate in the conduct and reporting of this trial. They will use computer-generated random sequences, stratified by study site, to assign participants to the two interventions. Labor management will be similar in the two groups except for the timing of maternal pushing effort. Analysis will follow the intention-to-treat principle. The use of broad inclusion criteria and intention-to-treat analysis will allow a more conservative estimate of differences in outcomes between the two strategies and allow a better estimate of effectiveness and public health implications of practice change than would pure estimate of efficacy alone.