To assess the effectiveness of intrapartum resuscitation treatments and the improvement of category II foetal heart rate (FHR) tracings was the purpose of this study. All patients with category II FHR tracings receiving intrauterine resuscitation: maternal oxygen, intravenous fluid bolus, amnioinfusion, or tocolytic administration were included in this secondary analysis of a randomised study of intrapartum foetal electrocardiographic ST-segment analysis. The primary goal was to improve to category I in 60 minutes. FHR trace improvement to category I 30–60 minutes after intervention and composite neonatal outcome were secondary objectives. Of the 11,108 randomised patients, 2,251 received at least one qualifying intervention for category II FHR tracings: 63.7 percent improved to category I within 60 minutes, and 50.5 percent improved between 30 and 60 minutes. Only 3.4 percent had a caesarean delivery and 4.1 percent had an operational vaginal delivery within 60 minutes of the intervention due to unsatisfactory foetal condition. The most prevalent intervention was the delivery of oxygen. Among the oxygen-treated subgroups defined by the American College of Obstetricians and Gynecologists, the absent FHR accelerations and absent–minimal FHR variability subgroup was more likely to convert to category I within 60 minutes than the FHR accelerations or “moderate FHR variability” subgroup. The total incidence of composite neonatal adverse outcome for category II tracings was 2.9 percent, with 2.8 percent improving to category I within 60 minutes and 3.2 percent not improving within 60 minutes. However, the group that improved had a 29% reduced chance of receiving higher quality newborn care.

Within 60 minutes of care, over two-thirds of category II FHR tracings improved to category I, with a reasonably low overall rate of the composite neonatal adverse outcome.