Head-to-body delivery interval and risk of fetal acidosis and hypoxic ischaemic encephalopathy in shoulder dystocia: a retrospective review

Abstract

Objective To examine the association between head-to-body delivery interval (HBDI) and cord arterial pH and base excess (BE), and the risk of development of hypoxic ischaemic encephalopathy (HIE). Design Retrospective review.Setting A university hospital.Population Pregnancies complicated with shoulder dystocia during the period 1995-2009.Methods Cases were identified from a search of the hospital electronic delivery records. Cord arterial pH and BE, and the incidence of HIE and perinatal death, were retrieved from medical records and correlated with HBDI, birth weight, mode of delivery and presence of nonreassuring fetal heart rate pattern and maternal diabetes using univariate analysis, followed by multivariate analysis.Main outcome measures Any association between cord pH and HBDI.Results Of the 200 cases identified, the mean (standard deviation) HBDI was 2.5 minutes (1.5 minutes). Both HBDI and the presence of nonreassuring fetal heart rate pattern were independent factors for pH, and HBDI was the only significant factor for BE. Arterial pH dropped at a rate of 0.011 per minute [95% confidence interval (95% CI), 0.017-0.004; P = 0.002] with HBDI. The mode of delivery, birth weight and maternal diabetes did not affect blood gas levels. The respective risks of severe acidosis (pH < 7) and HIE with HBDI of <5 minutes were 0.5% and 0.5% versus 5.9% and 23.5% with HBDI ‡ 5 minutes.Conclusions Cord arterial pH drops with HBDI during shoulder dystocia, but the risk of acidosis or HIE is very low with HBDI < 5 minutes.Keywords Acidosis, base excess, head-to-body delivery interval, hypoxic ischaemic encephalopathy, shoulder dystocia, umbilical cord pH.

Pregnancy week at delivery and the risk of shoulder dystocia: a population study of 2 014 956 deliveries

“…[1][2][3][4][5] Shoulder dystocia is defined as a failure to spontaneously deliver the fetal shoulders after delivery of the head. 6 High offspring birthweight is the most important risk factor for shoulder dystocia.…”

Predictive factors for the success of McRoberts’ manoeuvre and suprapubic pressure in relieving shoulder dystocia: a cross-sectional study

“…All consecutive cases of shoulder dystocia reported from 1995 to 2009 inclusively were identified from our hospital electronic database. As per our previous studies [2, 3], shoulder dystocia was defined as either a need to perform an additional obstetric manoeuvre in addition to downward traction of the fetal neck or when the head to body delivery interval was longer than 1 min [17]. Cases were only included for analysis if McRoberts’ manoeuvre with or without suprapubic pressure (M+/−S) was the first manoeuvre performed, and documentation was available regarding the management of dystocia.…”

“…In a brief few minutes it can lead to fetal morbidity and mortality [2–4], and in attempt to expedite delivery also maternal morbidity such as postpartum haemorrhage and major perineal tears [5]. An attempt to identify predictors of shoulder dystocia to sanction the option of caesarean section has only returned risk factors with low predictive value [6, 7].…”

“…In order to perform McRoberts’ manoeuvre and suprapubic pressure correctly and effectively, there must be adequate staff available, including two persons to hyper-flex the maternal hips (one on each side), a third one to apply suprapubic pressure, and another one to apply traction on the fetal head. Failure to summon additional staff to assist immediately may delay the use of more effective rotational methods or posterior arm delivery, and increase the risk of fetal hypoxia [2]. Thus it is necessary to review the usefulness of these frequently used first-line manoeuvres, by investigating which factors contributing to their success or failure, and in doing so decide how strongly one must adhere to a fixed protocol in each scenario.…”

“…The root of this current review stems from two previous studies published by our group regarding the head-to-shoulder delivery interval and perinatal outcomes of shoulder dystocia [2, 3]. We subsequently noted that the 25 % success rate of McRoberts’ manoeuvre and suprapubic pressure in our Asian centre was similar to a recently published paper from the Netherlands (23.8 %) [16], but was significantly lower than that reported in other predominantly Caucasian centres such as that of MacKenzie et al and Gherman et al (46 and 42 % respectively) [13, 15].…”