XML Template (2014) [3.12.2014–10:44am] //blrnas3.glyph.com/cenpro/ApplicationFiles/Journals/SAGE/3B2/SCMJ/Vol00000/140076/APPFile/SG-SCMJ140076.3d

(SCM)

[1–7] [INVALID Stage]

Scott Med J OnlineFirst, published on December 4, 2014 as doi:10.1177/0036933014563458

Original Article

Screening and management of gestational diabetes mellitus in Scottish obstetric units: a national survey

Scottish Medical Journal 0(0) 1–7 ! The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0036933014563458 scm.sagepub.com

Laura I Stirrat1, Fiona C Denison2, Corinne DB Love3, Robert S Lindsay4 and Rebecca M Reynolds5

Abstract Background and aims: The last study of screening practices for gestational diabetes (GDM) in the UK concluded that a lack of consensus about screening was due to a lack of clinical guidelines. We aimed to determine current practices in Scotland since new guidelines recommended that diagnosis should be made at a lower level of hyperglycaemia. Method and results: An online questionnaire designed to investigate the screening and management of GDM was distributed to all maternity units in Scotland managing women with GDM (n ¼ 15) for completion by relevant clinical team members. The response rate was 100%. Considerable variation in clinical practice existed between units. Thirteen units (86.7%) had adopted the lower glucose tolerance values for diagnosis of GDM (fasting 5.1 mmol/L; 2-h 8.5 mmol/L) recommended by the Scottish Intercollegiate Guidelines Network in 2010. Available data from units using this guideline (n ¼ 3) revealed a significant increase in the percentage of women diagnosed with GDM between 2010 and 2012 (2010: 1.28%, 2012: 2.54%; p < 0.0001). Conclusion: Despite provision of clinical guidelines, there are still inconsistencies in screening and management of GDM in Scotland. If a similar increase in the prevalence of GDM is experienced across Scotland, there will be major implications for health care provision and resource allocation.

Keywords Gestational diabetes, pregnancy, screening, management

Introduction Maternal hyperglycaemia is associated with adverse pregnancy outcomes,1 and diagnosis and treatment of gestational diabetes (GDM) improve outcomes.2 Obesity is as an independent risk factor for GDM,3 and its prevalence in Scotland has increased significantly during the last two decades (17% of adults aged 16–64 in 1995 to 27% in 2010).4 It is estimated that 30% of the antenatal population in the United Kingdom are obese5 and this is likely to have a significant impact on the prevalence of GDM. Screening and management of GDM are long-standing subjects of controversy.6–8 The last national survey of screening practices for GDM in the United Kingdom9 published in 1999, showed there was little consensus about appropriate screening, and concluded that national guidelines would probably be welcomed. Since then several major studies have clarified some of the main issues1,2,10 and have informed national clinical guidelines.6–8

1 Clinical Research Fellow, Medical Research Council Centre for Reproductive Health, Queens Medical Research Institute, University of Edinburgh, UK; Simpsons Centre for Reproductive Health, Royal Infirmary of Edinburgh, UK 2 Reader/Honorary Consultant in Maternal and Fetal Health, Medical Research Council Centre for Reproductive Health, Queens Medical Research Institute, University of Edinburgh; Simpsons Centre for Reproductive Health, Royal Infirmary of Edinburgh, UK 3 Consultant Obstetrician, Simpsons Centre for Reproductive Health, Royal Infirmary of Edinburgh, UK 4 Reader, Institute of Cardiovascular Sciences and Medical Sciences, University of Glasgow, UK 5 Professor of Metabolic Medicine and Honorary Consultant Physician, Endocrinology Unit, University/British Heart Foundation Centre for Cardiovascular Science, Queens Medical Research Institute, University of Edinburgh, UK

Corresponding author: Rebecca M Reynolds, Endocrinology Unit, University/BHF Centre for Cardiovascular Science, Queen’s Medical Research Institute, 47 Little France Crescent, Edinburgh EH16 4TJ, UK. Email: [email protected]

XML Template (2014) [3.12.2014–10:44am] //blrnas3.glyph.com/cenpro/ApplicationFiles/Journals/SAGE/3B2/SCMJ/Vol00000/140076/APPFile/SG-SCMJ140076.3d

(SCM)

[1–7] [INVALID Stage]

2 In 2010, the International Association of Diabetes and Pregnancy Study Groups (IADPSG) reviewed the results of the hyperglycaemia and adverse pregnancy outcomes study1 and conceded that oral glucose tolerance test (OGTT) values for diagnosis of GDM should be lower (fasting 5.1 mmol/L; 2 h 8.5 mmol/L) than previously recommended by the World Health Organisation (WHO) (fasting 5.5 mmol/L; 2 h 9.1 mmol/L).11 The Scottish Intercollegiate Guidelines Network (SIGN) incorporated this recommendation into guideline no. 1168 in 2010. Recommendations for management of GDM have also changed in parallel with new evidence from clinical trials. Insulin was recommended as first-line therapy after diet in 2008.7 There is still no evidence or guidance about the best strategy for antenatal care and fetal surveillance.8 We hypothesised that the increasing prevalence of maternal obesity and lowering of diagnostic values for OGTT would have contributed to an increased prevalence of GDM in Scotland since 2010. To our knowledge, this is the first study to evaluate this. We aimed to determine the current practices for screening and management of GDM in Scotland.

Method An eight-page structured online survey was designed to investigate screening, diagnosis and management practices for GDM in Scottish maternity units. Questions were asked about the size of individual maternity units, number of GDM diagnoses per year, screening policies and diagnostic criteria for GDM, multidisciplinary input, targets for glycaemic control and medication used, frequency of routine antenatal visits and fetal monitoring, policies for intrapartum care and postnatal follow-up. Following review by consultant obstetricians and diabetologists in Scotland, the questionnaire was distributed to the obstetric lead for diabetes in each maternity unit where women with GDM deliver to either complete or to give to appropriate person to complete. Surveys were not sent to units in the Outer Hebrides, Shetland or Orkney, as although women with GDM receive some antenatal care in their local unit, they usually deliver in a mainland hospital. Descriptive statistics was used to describe the frequency of common elements of clinical practice and they were compared using chi-squared. Data were analysed using Statistical Package for the Social Sciences version 20. A p value of < 0.05 was considered significant.

Results Fifteen consultant-led units were invited to take part and submitted a survey (response rate 100%). Surveys

Scottish Medical Journal 0(0)

Figure 1. Increasing number of GDM diagnoses in three maternity units in Scotland. During 2010, 2011 and 2012, there was an increase in the number of GDM diagnoses, but this was not statistically significant as a proportion of the total number of deliveries. Displayed are number of GDM diagnoses for three maternity units who provided data for 2010, 2011 and 2012. For each maternity unit (year [n ¼ number of GDM diagnoses, % of total deliveries]. P value from chi-square test of diagnosis and delivery numbers for the three maternity units combined, testing between 2010 and 2012: p < 0.0001. Maternity unit 1 (black bars): 2010 [n ¼ 7, 0.64% of 1096 deliveries], 2011 [n ¼ 9, 0.75% of 1199 total deliveries] and 2012 [n ¼ 24, 1.99% of 1208 deliveries]. Maternity unit 2 (white bars): 2010 [n ¼ 54, 1.42% of 3790 deliveries), 2011 [n ¼ 55, 1.45% of 3791 deliveries] and 2012 [n ¼ 94, 2.57% of 3652 deliveries]. Maternity unit 3 (grey bars): 2010 [n ¼ 62, 1.3% of 4653 deliveries], 2011 [n ¼ 98, 2.05% of 4761 deliveries] and 2012 [n ¼ 120, 2.66% of 4513 deliveries].

were completed by combinations of consultant obstetricians (n ¼ 13), diabetologists (n ¼ 3), diabetes specialist nurses (DSN) (n ¼ 1) and midwives (n ¼ 1). Three units (20%) reported the number of GDM diagnoses in 2010, 2011 and 2012, which revealed a significant increase in number of diagnoses during this time (p < 0.0001) (Figure 1).

Screening All units screened women for GDM, but there was considerable variation in screening practices. The most common screening policies were selective biochemical screening based on clinical risk factors alone (6/15; 40%), and a combination of universal biochemical plus clinical risk-factor screening (6/15; 40%). Three units (20%) practiced a universal biochemical screening policy. The specific clinical risk factors used were inconsistent (Table 1) and four units specified that they would screen women with a body mass index (BMI) of 35 kg/m2 (n ¼ 2), or BMI of 40 kg/m2 (n ¼ 2); higher than the recommended BMI >30 kg/m2. The maternity units using an increased maternal BMI for screening did not comment about whether this was pragmatic based on resource or on other grounds.

XML Template (2014) [3.12.2014–10:44am] //blrnas3.glyph.com/cenpro/ApplicationFiles/Journals/SAGE/3B2/SCMJ/Vol00000/140076/APPFile/SG-SCMJ140076.3d

(SCM)

[1–7] [INVALID Stage]

Stirrat et al.

3 Table 1. Screening based on risk factors. Clinical risk factor

Number (%) of maternity units

BMI >30 kg/m2 Previous macrosomic baby (4.5 kg) Family history (first degree relative with diabetes) Family origin with a high prevalence of diabetes Presence of glycosuria Presence of polyhydramnios Large for gestational age

9 11 11 11 5 9 8

(53.3) (73.3) (73.3) (73.3) (33.3) (64.2) (53.3)

Note: BMI, body mass index.

Table 2. Antenatal home blood glucose measurements: timings and targets. Blood glucose measurement

Number (%) of maternity units

Number of readings per day (range)

Upper limit of targets (mmol/L) Range (median)

Fasting Preprandial 1 h postprandial 2 h postprandial

12/15 11/15 3/15 10/15

0–4 0–3 0–3 1–4

5.3–8 5–6 8 6–8

(80) (73.3) (20) (66.7)

Early screening (‘up to 20 weeks’) was performed using combinations of fasting blood glucose (FBG) (4/15; 26.7%), HbA1c (5/15; 33.3%), random blood glucose (RBG) (5/15; 33.3%) and 75 g OGTT (9/15; 60%). Early screening was performed by eight units; five units (33.3%) performed early screening only for women who have had previous GDM, and a further three units (20%) performed early screening for any women with clinical risk factors for GDM (20%). The actual timing and use of these screening methods varied. Some maternity units specified that they would use OGTT for women with a previous history of GDM at a variety of gestations including at booking, 14 weeks, 16 weeks and 24 weeks. Screening between 20 and 28 weeks was performed with OGTT (11/15; 73.3%), RBG (11/15; 73.3%), FBG (2/15; 13.3%) and HbA1c (1/15; 6.6%).

Diagnosis All units used a 75 g OGTT to diagnose GDM. The latest gestation at which GDM was formally diagnosed and managed ranged from 34 to 42 weeks of gestation (median 38 weeks). Units did not comment how they would approach women with raised blood glucose after their maximal gestation for formal diagnosis and management. Thirteen units (86.7%) had adopted the OGTT values as recommended in SIGN no. 116 (fasting 5.1 mmol/L; 2-h 8.5 mmol/L). Two units that used higher old values recommended by the WHO (fasting

(5.5) (5) (8) (7)

5.5 mmol/L, 2-h 9.1 mmol/L) explained that this was due to cost and logistical reasons.

Diabetes management All units reported that women who required glucoselowering medication received joint care from a consultant obstetrician and diabetologist. Four units (26.7%) reported diet-controlled women received midwifery-led antenatal care with DSN input. In three units (20%), women were only reviewed by a consultant diabetologist if they were receiving oral glucose-lowering agents, or insulin therapy (3/15; 20%), or if blood sugars were not well controlled (2/15; 13.3%). All units reported that all women had input from a dietician, either in person (14/15; 93.3) or by telephone consultation (1/15; 6.6%). Home blood glucose monitoring (HBGM) was taught individually in 11 units (73.3%) and in groups in 4 units (28.6%). Teaching was delivered by combinations of DSNs (11/15; 73.3%), midwives (4/15; 26.6%), dieticians (2/15; 13.3%) and clinical support workers (1/15; 6.7%). There was evidence of variation in the type, frequency and targets of blood glucose measurements (Table 2). The most commonly used measurements were FBG (upper limit median 5.5 mmol/L), preprandial (upper limit median 5 mmol/L) and 2-h postprandial (upper limit median 7 mmol/L). Only three units asked women to measure 1-h postprandial values.

XML Template (2014) [3.12.2014–10:44am] //blrnas3.glyph.com/cenpro/ApplicationFiles/Journals/SAGE/3B2/SCMJ/Vol00000/140076/APPFile/SG-SCMJ140076.3d

(SCM)

[1–7] [INVALID Stage]

4

Scottish Medical Journal 0(0)

Metformin was used as the first-line glucose-lowering agent by 13 units (86.7%). A wide range of combinations of insulin regimens and preparations were used (Table 3). Ten units (66.7%) never used fixed mixture insulin preparations.

formal antenatal clinic review increased with advancing gestation, and differed according to treatment type (diet 10/15; oral 10/15; insulin 12/15).

Antenatal clinical reviews

Fetal growth and liquor volume ultrasound were most commonly used for routine antenatal fetal monitoring, commencing at 26 weeks and 24 weeks of gestation, respectively (Table 4). Umbilical Doppler ultrasound was commenced as early as 26 weeks of gestation. Cardiotograph (CTG) fetal heart monitoring was used least commonly, in only six maternity units.

The frequency of routine antenatal review varied according to treatment type (Figure 2). Most women were reviewed on a fortnightly basis, and most dietcontrolled women were formally reviewed on a monthly basis (10/15; 66.7%). In many units, the frequency of

Antenatal fetal monitoring

Labour and delivery Table 3. Insulin regimens and preparations. Insulin type Insulin regime Quick acting Long acting Basal bolus Fixed mixture Insulin preparations Actrapid Apidra Humalog Novorapid Novomix 30 Humalog mix 25 Humulin M3 Humulin I Insulatard Lantus Levemir

Number (%) of maternity units 11 10 10 5

(73.3) (66.7) (66.7) (33.3)

2 1 7 10 4 3 3 9 7 7 3

(13.3) (6.6) (46.6) (66.7) (26.7) (20) (20) (60) (46.7) (46.7) (20)

All units recommended delivery in a consultant-led unit, and induction of labour (IOL) by 40 weeks of gestation if glucose-lowering medication is taken. Diet-controlled women underwent IOL between 38 and 42 weeks of gestation (median between 40–40 + 6 weeks). Frequency of intrapartum blood glucose monitoring ranged from hourly (8/15; 53.3%), 2-hourly (1/15; 6.6%) and at normal ‘meal-times’ (1/15; 6.6%). In two units, blood glucose monitoring was not routinely performed during labour. Targets for blood glucose in labour ranged from 4 to 30 kg/m2) may be underdiagnosing GDM. An important consideration for units using an increased BMI cutoff would be the financial implications of carrying out more diagnostic testing in a population with increasing prevalence of obesity. Routine antenatal fetal monitoring practices in our survey varied between commencing relatively regular monitoring in the second trimester, to commencing in the late third trimester. SIGN states that ‘although regular fetal monitoring is common practice, no evidence has been justified on the effectiveness of any single or multiple techniques and therefore the clinical judgment of an obstetrician experienced in diabetic pregnancy is essential’.3 Robust outcome data are needed to inform best practice for routine fetal monitoring. Postnatal follow-up testing is recommended at least six weeks following delivery, to identify women who have developed type-2 diabetes. SIGN reports that there is no robust evidence to determine when followup testing should be carried out.8 Our survey suggests that not all women with GDM in Scotland are invited for postnatal testing, thus some cases of type-2 diabetes may be missed at this stage. Specific areas highlighted in the most recent SIGN guidelines8 as lacking robust evidence are the most appropriate screening and diagnosis strategy, targets and HBGM monitoring, antenatal fetal monitoring, timing of delivery and timing of postnatal follow-up. We observed a variation in practice for each of these. Our study also highlighted that one of the key reasons for variation in practice was differences in ability to implement the recommended guidelines. Other studies have shown that developed guidelines are often not

Scottish Medical Journal 0(0) implemented into clinical practice for reasons such as financial disincentives, difficulty relating to the guidelines, the target group of professionals, the culture and social setting.14 Indeed, when we explored reasons for two maternity units in our survey not adopting the new diagnostic criteria as recommended in SIGN no. 116, both units reported that this was for cost and logistical reasons. This view reflects the consensus of the National Institutes for Health (NIH), who in 2013 concluded that they would not adopt the lower diagnostic values as recommended by the IADPSG. The NIH panel were concerned that adoption of this criteria would increase the prevalence of GDM, and the corresponding costs and interventions; without clear demonstration of improvements in the most clinically important health and patient-centered outcomes.15

Conclusion The number of women diagnosed with GDM in Scotland appears to have increased in recent years and could have major implications for health care provision and resource allocation. There is a dearth of evidence about the best screening and management strategies and ongoing controversy is evident in current practice. It is likely that maternity units take a pragmatic approach to managing women with GDM within the confines of their resources. On the contrary, resources may be better allocated if a less intensive strategy for antenatal care was found to be sufficient to optimise pregnancy outcome. In order to determine the most economical use of resources for the increasing number of women being diagnosed with GDM, and also to optimise the health of women who are at increased risk of developing type-2 diabetes; more robust outcome data are needed to define best practice. Contribution to authorship L.I.S. designed and distributed the questionnaire, analysed the data and wrote the manuscript. F.C.D. designed the study and questionnaire, and edited the manuscript. C.D.B.L. contributed to the design of the study and the questionnaire, and approved the final manuscript. R.S.L. contributed to design of the study and the questionnaire, and edited the manuscript. R.M.R. designed the study and questionnaire and wrote the manuscript.

Acknowledgements We thank all Consultant Obstetricians and Diabetologists who reviewed and helped design the survey. We also thank all obstetricians, diabetologists and midwives who took the time to respond to the survey invitation.

Declaration of conflicting interests None declared.

XML Template (2014) [3.12.2014–10:44am] //blrnas3.glyph.com/cenpro/ApplicationFiles/Journals/SAGE/3B2/SCMJ/Vol00000/140076/APPFile/SG-SCMJ140076.3d

(SCM)

[1–7] [INVALID Stage]

Stirrat et al. Funding LIS is funded by Tommys. We also acknowledge the support of the British Heart Foundation.

Guarantor Professor Rebecca Reynolds.

References 1. Group HSCR, Metzger BE, Lowe LP, et al. Hyperglycemia and adverse pregnancy outcomes. N Engl J Med 2008; 358: 1991–2002. PubMed PMID: 18463375. 2. Crowther CA, Hiller JE, Moss JR, et al. Effect of treatment of gestational diabetes mellitus on pregnancy outcomes. N Engl J Med 2005; 352: 2477–2486. PubMed PMID: 15951574. 3. Kim C, Berger DK and Chamany S. Recurrence of gestational diabetes mellitus: a systematic review. Diabet Care 2007; 30: 1314–1319. PubMed PMID: 17290037. 4. Keenan K, Grant I and Ramsay J. Scottish Health Survey: Topic Report – Obesity. Edinburgh, Scottish Government, 2011. Available at http://www.scotland. gov.uk/Publications/2011/10/25091711/0. 5. Fitzsimons KJ, Modder J, Centre for Maternal and Child Enquires, et al. Setting maternity care standards for women with obesity in pregnancy. Semin Fetal Neonatal Med 2010; 15: 100–107. PubMed PMID: 19939755. 6. SIGN. Scottish Intercollegiate Guideline Network. Management of diabetes. SIGN no 55. 2001: 37–38. . 7. NICE. National Institute for Health and Clinical Excellence. Diabetes in Pregnancy. NICE no 63. 2008: 60–78. Available at http://www.nice.org.uk/guidance/ cg063.

7 8. SIGN. Scottish Intercollegiate Guidelines Network. Management of diabetes. A National clinical guideline. SIGN no 116. 2010: 56–70. Available at http://sign.ac.uk/ pdf/sign116.pdf. 9. Mires GJ, Williams FL and Harper V. Screening practices for gestational diabetes mellitus in UK obstetric units. Diabet Med 1999; 16: 138–141. PubMed PMID: 10229307. 10. Rowan JA, Hague WM, Gao W, et al. Metformin versus insulin for the treatment of gestational diabetes. N Engl J Med 2008; 358: 2003–2015. PubMed PMID: 18463376. 11. International Association of D Diabetes and Pregnancy Study Groups Consensus Panel., et al. International association of diabetes and pregnancy study groups recommendations on the diagnosis and classification of hyperglycemia in pregnancy. Diabetes Care 2010; 33: 676–682. PMID: 20190296. 12. Scott DA, Loveman E, McIntyre L, et al. Screening for gestational diabetes: a systematic review and economic evaluation. Health Technol Assess 2002; 6: 1–161. PubMed PMID: 12433317. 13. Chu SY, Callaghan WM, Kim SY, et al. Maternal obesity and risk of gestational diabetes mellitus. Diabet Care 2007; 30: 2070–2076. PubMed PMID: 17416786. 14. Grol R and Grimshaw J. From best evidence to best practice: effective implementation of change in patients’ care. Lancet 2003; 362: 1225–1230. PubMed PMID: 14568747. 15. Vandorsten JP, Dodson WC, Espeland MA, et al. NIH consensus development conference: diagnosing gestational diabetes mellitus. NIH Consensus State-of-the-Sci Statements 2013; 29: 1–31. PubMed PMID: 23748438.

Screening and management of gestational diabetes mellitus in Scottish obstetric units: a national survey.

The last study of screening practices for gestational diabetes (GDM) in the UK concluded that a lack of consensus about screening was due to a lack of...
136KB Sizes 1 Downloads 4 Views