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The ability of new fetal monitoring techniques to reduce complications and intervention rates was the focus of the recent 6th Internal Symposium on Intrapartum Surveillance (ISIS). The current state of fetal pulse oximetry and new electronic fetal monitoring (EFM) techniques formed a large part of the 2-day, biannual meeting held this July in Birmingham.

Objective The purpose of this study was to assess maternal and perinatal outcomes as a function of second-stage labor duration. Study Design We assessed outcomes in nulliparous laboring women who were enrolled in a trial of fetal pulse oximetry. Results Of 5341 participants, 4126 women reached the second stage of labor. As the duration of the second stage increased, spontaneous vaginal delivery rates declined, from 85% when the duration was Conclusion The second stage of labor does not need to be terminated for duration alone.

ObjectiveTo report an economic analysis of the Australian intrapartum fetal pulse oximetry (FPO) multicentre randomized controlled trial (the FOREMOST trial), which examined whether adding FPO to conventional cardiotocographic (CTG) fetal monitoring (intervention group) was a cost-effective intervention in reducing the operative delivery rate for non-reassuring fetal status, compared to CTG alone (control group).Study designCost-effectiveness analysis of the FOREMOST trial. Costs were for treatment related expenses, incorporating direct costs (including fetal monitoring) and Diagnosis Related Grouping costs. An incremental cost-effectiveness ratio (ICER) and cost effectiveness plane were calculated and sensitivity analysis conducted. The primary outcome (effect) was operative delivery for non-reassuring fetal status avoided in the intervention group, relative to the control group.ResultsThe ICER demonstrated a saving of $A813 for each operative birth for non-reassuring fetal status averted by the addition of FPO to CTG monitoring, compared to CTG monitoring alone. The majority (85.5%) of points within the cost-effectiveness plane fell to the right of the ICER line, suggesting that the intervention was deemed cost-effective.ConclusionThe addition of FPO to CTG monitoring represented a less costly and more effective use of resources to reduce operative delivery rates for non-reassuring fetal status, than conventional CTG monitoring alone.

ObjectiveFetal pulse oximetry improves the assessment of fetal well being during labor. We evaluated women´s satisfaction with their experience with this additional technology.Study designWe surveyed women participating in the FOREMOST trial, a randomized controlled trial comparing the addition of fetal pulse oximetry (FPO) to conventional cardiotocograph (CTG) monitoring (intervention group), versus CTG-only (control group), in the presence of non-reassuring fetal status during labor. Our survey evaluated three aspects of women´s experience: fetal-monitoring, labor and participation in the research. The survey was administered within a few days of giving birth and repeated three months later.ResultsThere were no differences between the intervention and control groups for women´s evaluations of their labor, fetal monitoring, research or overall experiences, when surveyed on the two occasions. Within each study group, there was a small but statistically significant decline in women´s scores for their experience of labor and overall experience from the initial survey close to the time of giving birth, to three months later. The magnitude of differences in responses over time was similar for the two groups. Women were more satisfied following a spontaneous or assisted vaginal birth than following cesarean section (Survey 1 p < 0.001, Survey 2 p < 0.001). Length of time the research midwife was present had a significant positive effect on women´s ratings of their experience several days after giving birth (p=0.006) but no effect at three months.ConclusionThe addition of fetal pulse oximetry for the assessment of fetal well-being during labor did not affect childbearing women´s perceptions of fetal monitoring or their labor. Women evaluated their experience in the research process positively overall. There were small changes in women´s perception of their satisfaction over time.

Advances in oximetry have allowed the obstetrician to measure oxygen saturation in the fetus with non-invasive transcutaneous techniques. The influence of caput succedaneum formation on the oxygen saturation results obtained with a pulse oximeter was studied in 30 newborn infants. Caput was associated with a reduced oxygen saturation reading (mean reduction of 15%; P less than 0.001). This effect is partly due to a true drop in local tissue oxygenation but is exacerbated by a systematic error intrinsic to the physics of spectrophotometry. If continuous intrapartum oximetry is ever to become a part of routine obstetric monitoring then probes that pass through the cervix beyond the caput of the presenting part will be required if erroneously low readings are to be avoided.