How Often is a Low Apgar Score the Result

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How often is a low Apgar score the resultof substandard care during labour?S Berglund,a H Pettersson,a S Cnattingius,b C Grunewalda

a Department of Clinical Science and Education, Karolinska Institutet Sodersjukhuset and b Clinical Epidemiology Unit, Department of

Medicine, Karolinska Institutet, Stockholm, Sweden

Correspondence:Dr S Berglund, Department of Obstetrics and Gynaecology, Sodersjukhuset, S-118 83, Stockholm, Sweden.

Email [email protected]

Accepted 10 March 2010. Published Online 21 April 2010.

Objective To increase our knowledge of the occurrence of

substandard care during labour.

DesignA population-based casecontrol study.

SettingStockholm County.

PopulationInfants born in the period 20042006 in Stockholm

County.

MethodsCases and controls were identified from the Swedish

Medical Birth Register, had a gestational age of33 complete

weeks, had planned for a vaginal delivery, and had a normal

cardiotocographic (CTG) recording on admission. We compared

313 infants with an Apgar score of


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1 Neglecting to supervise fetal wellbeing.

2 Improper use of oxytocin.

3 Neglecting signs of fetal asphyxia.

4 Substandard care during delivery.

Methods

We designed a population-based case-control study

including the seven delivery units of Stockholm County,

encompassing around 24% (n = 74 539) of all births in

Sweden (n = 309 140) during the years 20042006. Prema-

turity is one of the most important risk factors for develop-

ing cerebral palsy.5 We chose to include only infants with a

gestational age of at least 33 completed weeks, which is the

time point when immaturity of the lungs is no longer

treated with betamethasone. The gestational age was

defined by a second-trimester ultrasound, and the infants

were identified by the Swedish Medical Birth Register. As

low Apgar score correlates well with asphyxia, and is, as

opposed to acidbase balance, nearly always registered,cases were defined as infants born with an Apgar score of


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Care during labour was considered substandard when

supervision of fetal wellbeing was neglected. This included

when there were no CTG recordings for more than

2.5 hours after the admission test or in between CTG

recordings, and when CTG recordings were not interpret-

able because they were of poor quality. In cases of continu-

ous abnormal CTG but normal FBS, a follow-up of FBS

should have been carried out every 2030 minutes, depen-

dent on the stage of delivery.6 Moreover, we considered

that there had been substandard care during labour when

signs of fetal asphyxia were neglected, and when there was

untimely action on abnormal CTG (i.e. action was taken

more than 45 minutes from the onset of an abnormal CTG

to birth), uterine hyperstimulation, or if the oxytocin infu-

sion was increased despite an abnormal CTG (Box 1).

We defined imminent asphyxia as an FBS with a pH of

4.8 mmol/l, a terminal CTG, or

abnormal CTG tracings with prolonged bradycardia, tachy-

cardia, a complicated variable, or late decelerations. We

considered that care was substandard during delivery in thecases of imminent asphyxia if the time from the decision

to deliver to birth exceeded 30 minutes, if there was a

spontaneous vaginal delivery despite longstanding (at least

45 minutes) abnormal or uninterpretable CTG recordings,

or if there was a complex instrumental delivery. Complex

instrumental delivery was defined as an inappropriate trial

of labour in a singleton delivery with a vacuum extractor

or forceps in the following circumstances: incomplete

cervical dilatation, non-cephalic presentation or cephalic

malpresentation, non-engaged fetal head, or a clear indi-

cation of cephalopelvic disproportion. The definition of a

complex instrumental delivery also included a delivery by

vacuum extraction exceeding more than 20 minutes or

following more than two cup detachments (Box 2).1317

Statistics

Sample sizeWe designed the study as a case-control study, frequency

matched for year of delivery. A power analysis was com-

pleted before implementation. A sample size estimate of

319 patients in each group (638 in total) would provide an

80% power to detect a two-fold increase in the odds of

substandard care between infants with low (cases) and full

(controls) Apgar scores, with a two-sided alpha = 0.05.

This calculation is based on the assumption that 10% of

the controls were subjected to substandard care, and was

calculated in Sample Power 2.0. Among infants born in

Stockholm County in 20042006, there were 415 infants

with a gestational age of33 completed weeks that had Ap-

gar scores of


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Table 1. Descriptive data and risk for an Apgar score of


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analyses, we adjusted for maternal care and infant charac-

teristics that were significantly (P< 0.05) associated with

an Apgar score of 0.05

indicates an acceptable fit.

We chose to divide the year into three seasons spring,

summer and autumn to investigate if there were differ-

ences in the risks of being born in the spring season, which

is the busiest time period of the year, or in the summer,

when there could be a shortage of skilled obstetricians and

midwives because of holidays, compared with being bornin the autumn (Table 1).

As all CTG tracings were scrutinised by only one of the

authors (S.B.), we independently investigated the interob-

server agreement between S.B. and an expert within the

field (Professor Ingemar Ingemarsson, I.I., a senior consul-

tant). One hundred randomly selected intrapartal CTG

tracings from the cases and controls were assessed by S.B.

and I.I., and were classified as normal, intermediary or

Table 2. Substandard care during labour and risk of an Apgar score of


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abnormal, and if the pattern changed, the time point was

noted accordingly. The interobserver agreement in the

assessment of CTG tracings between two senior consultants

(S.B. and I.I.) was 86%, which was considered to be satis-

factory.19,20

Finally, we estimated the (unadjusted) attributable risk

related to any substandard care (according to Boxes 1 and

2 and Tables 2 and 3), and a corresponding 95% confi-

dence interval, by applying the delta method. The attribut-

able risk assumes a causeeffect relationship between

exposure (substandard care) and disease (low Apgar score

at 5 minutes), and provides an estimate of the proportion

of cases that are possibly related to substandard care.21,22

Analyses were performed in spss 17.0 (SPSS Inc., Chi-

cago, IL, USA). The study was approved by the Research

Ethics Committee at the Karolinska Institutet, Stockholm

(no. 2008/1375).

Results

Of 313 infants with Apgar scores of


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1 year of stated infertility appeared to have a reduced risk.

There were no differences between cases and controls in

smoking habits, family situation, mothers country of birth,

maternal height, body mass index (BMI), hypertension, or

pregestational or gestational diabetes (data not shown).

Characteristics related to care significantly associated

with increased risk of a low Apgar score were induction of

labour and use of epidural (Table 1). The risk of a low

Apgar score was not influenced by season of birth, hour of

birth, location of maternity hospital, or day of delivery

(weekdays versus weekends).

Compared with term (3741 weeks of gestation) infants,

both preterm (3336 weeks of gestation) and post-term

(42 weeks of gestation) infants had a more than doubled

risk of low Apgar score. Very small for gestational age

infants faced a five-fold increase in risk, and moderately

large for gestational age infants had a doubled risk of a low

Apgar score, compared with normal weight infants. Boys

had a 50% increase in risk compared with girls, and infants

in other than occiput anterior presentation had a morethan doubled increase in risk compared with infants pre-

sented in occiput anterior position (Table 1).

Forty percent (n = 124) of infants with an Apgar score

of


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Discussion

In this population-based case-control study from Stock-

holm County, Sweden, we found substandard care not only

in 62% of infants who had an Apgar score of


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Our study shows that necessary efforts to make delivery

safer include infrastructural changes and institutional

incentives. Aviation used to be a high-risk industry, but

has been transformed by the widespread utilisation of

information technology, in particular autopilots, and sev-

eral mistakes must therefore be made before an accident

can take place. In addition to aviation, oil and nuclear

industries, the formal investigation of incidents, consisting

of a series of routinely followed steps, is well established.

Studies in these areas have led to a broader understanding

of the causes of accidents, with less focus on the individ-

uals mistake and more on pre-existing organisational fac-

tors. Such studies have also illustrated the complexity of

the chain of events that may lead to an adverse out-

come.3942

Every case of asphyxia can be used as a learning exam-

ple. Perinatal audits consisting of professionals within peri-

natal care are useful when investigating shortcomings in

conjunction with childbirth. The aim of an audit is hence

to initiate adjustments, optimise the quality of care andimprove interprofessional collaboration. Perinatal audits

have been shown to be efficient in the Netherlands, where

perinatal mortality in 1999 was ranked the highest (11.4/

1000) among the 25 countries of the European Union.43,44

The use of clinical dashboards for monitoring and present-

ing regular healthcare performance is gaining popularity.

Clinical dashboards may be useful in predicting trends in

various clinical governance parameters, enabling immediate

action to be taken to rectify patient safety issues. When a

maternity dashboard was introduced at St Georges Hospi-

tal, London, in 2007, there was an amberred trend of

increasing emergency caesarean section after failed instru-

mental deliveries. Immediate action was taken, with educa-

tional efforts focussed on hands-on ventouse training and a

daily review on emergency caesarean sections, after which

there was a decrease in the caesarean section rate from

26% to 20%.4547

Draycott et al.,48 in Bristol, UK, have demonstrated that

mandatory skills training in obstetric emergencies

improves neonatal outcome. Besides, educational efforts

among physicians and midwives may improve CTG inter-

pretation and fetal surveillance.49 Recently, the Swedish

Society of Obstetrics and Gynaecology has, in collabora-

tion with the Swedish Association of Midwives, developed

an internet-based interactive and freely available CTG edu-cational and training programme, providing a certificate

after having passed the final examination.50 Additionally,

standardised stickers for the interpretation of CTG have

been developed, and are now available on a national level.

However, although there are examples of successful out-

comes, such as the introduction of training and stickers,

it is uncertain to what extent improvements can be

achieved. In an online educational setting in CTG and

acidbase interpretation in the UK, the mean score in

written tests after education were around 63 and 83% for

midwives and obstetricians, respectively, which indicates

that additional educational efforts are needed.49 Questions

on whether there are a certain number of people who

suffer from cognitive dysfunction, resulting in pattern

dyslexia, have been raised.49 If so, besides training and

education, maybe CTG interpretation should be assessed

by at least two people, or by additional computerised

interpretation functions.23,51

Conclusion

Some form of substandard care during labour was present

in two-thirds of deliveries of infants with a low Apgar score

at 5 minutes, and in one-third of the controls. The main

reasons for substandard care were related to the misinter-

pretation of CTGs, not acting in a timely fashion on abnor-

mal CTGs, and the incautious use of oxytocin. Assuming

that substandard care is a risk factor for a low Apgar score,we estimate that the number of infants with an Apgar score

of


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AcknowledgementWe thank Professor Ingemar Ingemarsson for his kind par-

ticipation in the interobserver agreement investigation of

CTG interpretation.j

References

1 Berglund S, Grunewald C, Pettersson H, Cnattingius S. Severe

asphyxia due to delivery-related malpractice in Sweden 1990-2005.

BJOG 2008;115:31623.

2 Jonsson M, Norden SL, Hanson U. Analysis of malpractice claims

with a focus on oxytocin use in labour. Acta Obstet Gynecol Scand

2007;86:3159.

3 Hogan L, Ingemarsson I, Thorngren-Jerneck K, Herbst A. How often

is a low 5-min Apgar score in term newborns due to asphyxia?Eur J

Obstet Gynecol Reprod Biol 2007;130:16975.

4 Marsal K, Persson PH, Larsen T, Lilja H, Selbing A, Sultan B. Intra-

uterine growth curves based on ultrasonically estimated foetal

weights.Acta Paediatr 1996;85:8438.

5 Hagberg B, Hagberg G, Beckung E, Uvebrant P. Changing panorama

of cerebral palsy in Sweden. VIII. Prevalence and origin in the birth

year period 1991-94. Acta Paediatr 2001;90:2717.

6 Amer-Wohlin I, Herbst A. Eds: Hagberg H, Marcal K, Westgren M.

Fetal serveillance during labour; Textbook in Swedish:(Fosterovervak-

ning under forlossningen). Obstetrik 2008; Edition 1, pp. 25368.

7 Nordstrom L, Walldenstrom U. State of the Art: handling of the

normal labour. In Swedish (Handlaggning av normalforlossning).

Socialstyrelsen 2001 (www.socialstyrelsen.se/publikationer2001/2001-

123-1). Accessed 2 April 2010.

8 ACOG PRACTICE BULLETIN. Clinical management guidelines for

obstetricians - gynecologists Intra Partum Fetal Heart Monitoring:

nomenclature, Interpretation, and General Management Principles

2009;114:192202.

9 Badawi N, Kurinczuk JJ, Keogh JM, Alessandri LM, OSullivan F,

Burton PR, et al. Antepartum risk factors for newborn encephalop-

athy: the Western Australian case-control study. BMJ 1998;317:

154953.

10 Nordstrom L, Wiklund I. Eds: Hagberg H, Marcal K, Westgren M

The physiology and handling of labour. Textbook in Swedish

(Forlossningens fysiologi och handlaggning). Obstetrik 2008; Edition 1,

pp. 11329.

11 Cunningham G, Gant N, Leveno K, Gistrap L III, Hauth J, Wenstrom

K, et al. Induction and augmentation of labour. Williams Obstetrics

New York, USA: McGraw Hill Companies. 2001; Edition 21, pp.

46979.

12 Drennan K, Gouyert G, et al. Intrapartum Fetal Monitoring. Glob libr

womens med, (ISSN: 1756-2228) 2008: DOI 10.3843/GLOWM.

10202.

13 Miksovsky P, Watson WJ. Obstetric vacuum extraction: state of the

art in the new millennium. Obstet Gynecol Surv 2001;56:73651.

14 Sadan O, Ginath S, Gomel A, Abramov D, Rotmensch S, Boaz M,

et al. What to do after a failed attempt of vacuum delivery? Eur J

Obstet Gynecol Reprod Biol 2003;107:1515.

15 Martel MJ, MacKinnon CJ. Guidelines for vaginal birth after previous

Caesarean birth. J Obstet Gynaecol Can 2005;27:16488.

16 Teng FY, Sayre JW. Vacuum extraction: does duration predict scalp

injury? Obstet Gynecol 1997;89:2815.

17 Turner MJ, Agnew G, Langan H. Uterine rupture and labour after a

previous low transverse caesarean section. BJOG 2006;113:72932.

18 Berglund S, Grunewald C, Pettersson H, Cnattingius S. Risk factors

for asphyxia associated with substandard care during labor. Acta

Obstet Gynecol Scand 2010;89:3948.

19 Ojala K, Makikallio K, Haapsamo M, Ijas H, Tekay A. Interobserver

agreement in the assessment of intrapartum automated fetal elec-

trocardiography in singleton pregnancies. Acta Obstet Gynecol

Scand 2008;87:53640.

20 Westerhuis M, van Horen E, Kwee A, van der Tweel I, Visser GH,

Moons K. Inter- and intra-observer agreement of intrapartum ST

analysis of the fetal electrocardiogram in women monitored by

STAN.BJOG 2009;116:54551.

21 Coughlin SS, Benichou J, Weed DL. Attributable risk estimation incase-control studies. Epidemiol Rev 1994;16:5164.

22 Woodward M Study design and data analysis. Epidemiology, 2nd

edn. Florida, USA: Chapman & Hall: 1999, 283.

23 Ennis M, Vincent CA. Obstetric accidents: a review of 64 cases. BMJ

1990;300:13657.

24 Odd DE, Lewis G, Whitelaw A, Gunnell D. Resuscitation at birth and

cognition at 8 years of age: a cohort study. Lancet 2009;373:1615

22.

25 Lindstrom K, Hallberg B, Blennow M, Wolff K, Fernell E, Westgren

M. Moderate neonatal encephalopathy: pre- and perinatal risk fac-

tors and long-term outcome. Acta Obstet Gynecol Scand

2008;87:5039.

26 Steer PJ. Surveillance during labour. J Perinat Med 2009;37:4516.

27 Badawi N, Kurinczuk JJ, Keogh JM, Alessandri LM, OSullivan F, Bur-

ton PR, et al. Intrapartum risk factors for newborn encephalopathy:the Western Australian case-control study. BMJ 1998;317:15548.

28 Milsom I, Ladfors L, Thiringer K, Niklasson A, Odeback A, Thornberg

E. Influence of maternal, obstetric and fetal risk factors on the prev-

alence of birth asphyxia at term in a Swedish urban population. Acta

Obstet Gynecol Scand 2002;81:90917.

29 Nordstrom L, Ingemarsson I, Kublickas M, Persson B, Shimojo N,

Westgren M. Scalp blood lactate: a new test strip method for moni-

toring fetal wellbeing in labour. Br J Obstet Gynaecol

1995;102:8949.

30 ACOG. American College of Obstetricians and Gynecologists Task

Force on Neonatal Encephalopathy and Cerebral Palsy. Neonatal

Encephalopathy and Cerebral Palsy: Defining the pathogenesis and

pathophysiology. Washington DC: American college of Obstetricians

and Gynecologists, 2003.

31 Annappa R, Campbell DJ, Simpson NA. Fetal blood sampling inlabour and the decision to delivery interval. Eur J Obstet Gynecol

Reprod Biol 2008;141:102.

32 Blix E, Oian P. Interobserver agreements in assessing 549 labor

admission tests after a standardized training program. Acta Obstet

Gynecol Scand 2005;84:108792.

33 Blix E, Sviggum O, Koss KS, Oian P. Inter-observer variation in

assessment of 845 labour admission tests: comparison between mid-

wives and obstetricians in the clinical setting and two experts. BJOG

2003;110:15.

34 Berglund S, Nordstrom L. National survey (Sweden) of routines for

intrapartum fetal surveillance. Acta Obstet Gynecol Scand

2001;80:5523.

35 Murphy DJ, Koh DK. Cohort study of the decision to delivery interval

and neonatal outcome for emergency operative vaginal delivery. Am

J Obstet Gynecol2007;196:145. e17.36 Thomas J, Paranjothy S, James D. National cross sectional survey to

determine whether the decision to delivery interval is critical in

emergency caesarean section. BMJ 2004;328:665.

37 Kolas T, Hofoss D, Oian P. Predictions for the decision-to-delivery

interval for emergency cesarean sections in Norway. Acta Obstet

Gynecol Scand 2006;85:5616.

38 Butler J, Abrams B, Parker J, Roberts JM, Laros RK Jr. Supportive

nurse-midwife care is associated with a reduced incidence of cesar-

ean section. Am J Obstet Gynecol 1993;168:140713.

Substandard care resulting in low Apgar score

2010 The Authors Journal compilation RCOG 2010 BJOG An International Journal of Obstetrics and Gynaecology

977


11/11

39 Hamilton E, Wright E. Labor pains: unraveling the complexity of OB

decision making. Crit Care Nurs Q 2006;29:34253.

40 Burke CS, Salas E, Wilson-Donnelly K, Priest H. How to turn a team

of experts into an expert medical team: guidance from the aviation

and military communities. Qual Saf Health Care 2004;13(Suppl

1):i96104.

41 Thomas EJ, Sexton JB, Helmreich RL. Translating teamwork behav-

iours from aviation to healthcare: development of behavioural mark-

ers for neonatal resuscitation.Qual Saf Health Care 2004;13(Suppl1):i5764.

42 Vincent C, Taylor-Adams S, Chapman EJ, Hewett D, Prior S, Strange

P, et al. How to investigate and analyse clinical incidents: clinical risk

unit and association of litigation and risk management protocol.

BMJ 2000;320:77781.

43 Merkus JM. Perinatal mortality in The Netherlands: an audit is now

more necessary than ever. Ned Tijdschr Geneeskd 2008;152:6035.

44 de Reu P, Van Diem M, Eskes M, Oosterbaan H, Smits L, Merkus H,

et al. The Dutch Perinatal Audit Project: a feasibility study for nation-

wide perinatal audit in the Netherlands. Acta Obstet Gynecol Scand

2009;88:12018.

45 Chandraharan E The role of Maternity Dashboard in improving

patient care: 2 year experience in a tertiary centre. Oral presentation

at the FIGO konference in Capetown 2009. 2009.

46 Arulkumaran S, Wells M, Boddington R. Lessons learnt from the

reorganization of maternity services. Br J Hosp Med (Lond)

2008;69:747.

47 RCOG. Maternity dashboard, clinical performance and governance

score card. Good Practice no 7 2008.

48 Draycott T, Sibanda T, Owen L, Akande V, Winter C, Reading S,et al. Does training in obstetric emergencies improve neonatal out-

come? BJOG 2006;113:17782.

49 Beckley S, Stenhouse E, Greene K. The development and evaluation

of a computer-assisted teaching programme for intrapartum fetal

monitoring.BJOG 2000;107:113844.

50 www.ctgutbildning.se Anvandarnamn(user name):ctg Losenord

(password):utbildning. Accessed 2 April 2010.

51 Schiermeier S, Pildner von Steinburg S, Thieme A, Reinhard J, Daumer

M, Scholz M,et al.Sensitivity and specificity of intrapartum computer-

ised FIGO criteria for cardiotocography and fetal scalp pH during

labour: multicentre, observational study.BJOG 2008;115:155763.

Berglund et al.

978 2010 The Authors Journal compilationRCOG 2010 BJOG An International Journal of Obstetrics and Gynaecology

How Often is a Low Apgar Score the Result

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