Place for Figures 1, 2, 3
A deceleration can only be imprecisely/subjectively suspected on ‘Pinard auscultation’; unless one is estimating FHR using ‘multiple count strategy’. This involves counting heart beats separately for every 10-15 seconds segments during the period of auscultation which is a sound recommendation by the American College of Nurse-midwives (ACNM).4 This ‘multiple count strategy’ is certainly possible (was author’s practice) but difficult; hence rarely practiced if at all. However, this cumbersome practice becomes completely unnecessary where Doppler-devices are easily available which are designed to display temporal variations in FHR. A review article in 2015 highlighted that even with a Doppler-device, special care needs to be taken in detecting late FHR decelerations because the trough of the deceleration may have already passed and the recovering FHR (often in the normal range) immediately after the contraction have been misinterpreted as ‘accelerations’ leading to procrastination until the decelerations become severe.6,18 This may be the likely cause of presumed unexplained birth asphyxia after an apparently normal IA documentation.6 Following these findings, the Royal College of Obstetricians and Gynaecologists (RCOG) and Royal college of Midwives (RCM) are implementing a practice change to commence auscultation towards the end of the contractions (unpublished RCOG and RCM document). Unfortunately, this has been implemented with an erroneous advice that auscultation for 30 seconds after the contraction would suffice with total 1 minute of counting (unpublished document); obviously because of preoccupation with ‘counting’ fetal heart tones. However, extending auscultation to onset of next contraction would be safer, because in the presence of late decelerations or accelerations, the accurate baseline is best ascertained by observing the FHR display on the Doppler-device just before or at the onset next contraction.6 Additional safeguard would be to confirm acceleration only when preceded and followed by a normal baseline. The Doppler-device easily allows extension of the auscultation period very flexibly beyond 1 minute which seems crucial in confirming periodic FHR changes (figures 1-3). In contrast, the act of counting heart beats with Pinard stethoscope reaches its natural but arbitrary end at 1 minute and could unwarily preclude further flexible extension. Thus, the Doppler-device FHR display has a major advantage over ‘Pinard’ in discerning both the meaningful FHR baseline and periodic changes most importantly the late decelerations.