Pre-Existing & Gestational Diabetes

Transcription

1 Pre-Existing & Gestational Diabetes Part A Management of Antenatal Care Policy To ensure that all women presenting with pre-existing and gestational diabetes are appropriately monitored, managed and treated during their pregnancy, labour and postpartum period. Scope All midwifery and Obstetric medical staff All Hutt Valley District Health Board access holders Endocrinologists and Medical Registrars Diabetes Nurse Clinicians Dietician Definitions GDM- Gestational Diabetes is defined as any degree of glucose intolerance first recognised during pregnancy. This definition applies equally to those women who require insulin or metformin therapy and those who simply require dietary modification. Some of these women will be diagnosed post delivery to have Type 2 diabetes, impaired glucose tolerance (IGT), impaired fasting glucose (IFG) and occasionally Type 1 diabetes. Type 2 Diabetes the most common form of diabetes, it occurs when either the pancreas stops producing enough insulin, or the body becomes resistant to the insulin produced. It has been called Non Insulin Dependent Diabetes Mellitis or NIDDM in the past. It is a chronic disease developing over several years which may be treated using diet and exercise, oral medications such as metformin or glibenclamide, or may require insulin treatment. Type 1 Diabetes an autoimmune disease in which the pancreas s production of insulin decreases to very little or zero. It more commonly begins in childhood but can develop at any age. It used to be referred to as Insulin Dependent Diabetes Mellitis or IDDM. IGT Impaired Glucose Tolerance IFG Impaired Fasting Glucose Approved by Maternity Quality Committee Next due date: April 2015 Page 1 of 13

2 Risks and precautions Fetal/neonatal Risks: Maternal Risks: Macrosomia, shoulder dystocia & Miscarriage birth injuries eg nerve palsies, fractures Hypoglycaemia UTI, candida infections Respiratory distress Raised risk of PET Hyperbilirubinaemia Increased risk of IOL and of C/S Congenital anomalies Birth trauma IUGR esp. with hypertensive or Type 2 Diabetes in later life vascular disorders Unexplained intrauterine death Future risk of obesity and diabetes Screening and Referral Women with pre-existing Type 1 and Type 2 Diabetes These women will be referred in the first trimester to the Secondary Care/AND clinic, usually by their GP, to enable early blood glucose control, early treatment with insulin or metformin as necessary, and timely screening as per normal A/N care. Women with known impaired glucose tolerance (IGT or impaired fasting glucose (IFG) prior to pregnancy should be referred to the AND clinic in the first trimester. Gestational Diabetes At booking: All women are screened at booking for Type 2 diabetes by taking a full medical, family & obstetric history. Type 2 diabetes can go unrecognised for many years before symptoms appear. The risks associated with diabetes in pregnancy are known to be at least as high for Type 2 as for Type 1 diabetes. Cundy et al (2000) showed perinatal mortality with Type 2 significantly increased even over Type 1, mainly due to a greater level of late fetal death. Obesity may contribute to this. Early recognition of undiagnosed diabetes is important so treatment can be initiated to reduce its impact on pregnancy outcomes. Risk Factors for Type 2 Diabetes: Previous GDM PCOS Morbid obesity (Ethnic specific: Indian/Asian BMI 32, Polynesian BMI 37, everyone else BMI 35) Previous macrosomia: customised birthweight > 97 th centile Approved by Maternity Quality Committee Next due date: April 2015 Page 2 of 13

3 If no access to customised chart, 4700g Polynesian, 4400g European, 4000g Asian. Age over 40 years Two 1 st degree relatives with diabetes Previous unexplained stillbirth Persistant glycosuria Previous shoulder dystocia Women with the above risk factors can be offered an HbA1c at booking (even if the previous postnatal GTT was normal) and the reasons for this explained to the woman. If elevated> 50 she should be referred to the Secondary Care/AND clinic as most likely has undiagnosed pre-existing diabetes or IGT. If HbA1c is 41-49, discuss with the diabetes team. They may suggest referral or may request an OGTT at 14 weeks. If the HbA1c is normal, an OGTT is offered at weeks. If this GTT is normal repeat the GTT at weeks (or earlier if clinical suspicion occurs) weeks: Women with no risk factors for diabetes should be offered a screening test, the nonfasting 50g Glucose Challenge, or Polycose test. If the GCT result is 7.8mmol/l a fasting OGTT is required. The sensitivity of the Glucose Challenge has been reported as 80%, which means that 20% of women with GDM will have a GCT result <7.8mmol/l. Half of these women with a false negative result will have a result between mmol/l. It is recommended that if these women have a risk factor for GDM (as listed above, or macrosomia /polyhydramnios / increased wt gain) they should have a GTT. GDM is diagnosed with one or both of the following: - Fasting glucose 5.5mmol/l - Two hour glucose 9.0mmol/l If the two hour test result is >8.0mmol/l in a woman with a macrosomic baby or polyhydramnios, it would be appropriate to discuss with the Obstetrician in the AND regarding her management. A GCT result of >11 can be referred directly to the Secondary Care/AND clinic (GTT not required prior to referral). A diagnosis of GDM is an indication for written obstetric referral to Secondary Care to attend the Combined Obstetric/ Antenatal Diabetes clinic. See Appendix 1 - Screening for Diabetes in Pregnancy flowchart Approved by Maternity Quality Committee Next due date: April 2015 Page 3 of 13

4 Antenatal Care As a general rule, the secondary care obstetric team will have clinical responsibility for all women who require insulin/metformin treatment whereas women with well controlled diet controlled GDM can remain under the care of their LMC midwife. If a transfer of clinical responsibility occurs, then a three way conversation needs to occur between the obstetrician, the LMC and the woman. Midwifery care will be negotiable. Those women booking under a private obstetrician will continue to have their obstetric care with their obstetrician but will see the endocrinologist at the AND clinic 2-4 weekly or more frequently as their diabetes control warrants. The multidisciplinary team emphasises the importance of regular antenatal visits and strict adherence to dietary and medication regimes. Information on diet and exercise is provided. A letter stating the identity of the LMC, and a management plan, will be dictated at the first or second clinic visit by the obstetric team to the referring health care provider and LMC. In all cases a copy is forwarded to the woman s general practitioner, the LMC and the woman herself. To enable women to self monitor their blood glucose, a blood glucose monitor is provided. There is a clear expectation that this will be returned at the end of the pregnancy. Management in Early Pregnancy: Type 1, Type 2 and some GDM (possible undiagnosed Type 2) Women diagnosed with GDM before 20/40 are at higher risk and should be managed as for a woman with Type 2 diabetes. This care will include: - Accurate assessment of gestation using LMP and early USS. - Usual MSS1 or 2 screening offered. - Anatomy USS at weeks. - Consider detailed cardiac USS at 24 weeks. - Consider aspirin (& calcium) as there is a raised risk of preeclampsia. - Careful control of glucose levels with regular phone contact with diabetes nurse educators between clinic visits every 2-4 weeks. - Blood tests: HbA1c if not yet done, booking bloods, creatinine, LFTs, TFTs - MSU and check need for HVS/chlamydia screen Approved by Maternity Quality Committee Next due date: April 2015 Page 4 of 13

5 Management in later pregnancy: diet controlled GDM Following referral to the AND clinic with a diagnosis of GDM, women will be seen by the endocrinologist and diabetes nurse specialist and taught how to monitor their own blood glucose levels. They will also be seen by the secondary care obstetrician, who will review for potential complications such as macrosomia, polyhydramnios, IUGR and hypertensive disease. If dietary modifications and exercise are felt to be adequate in maintaining euglycaemia the woman will be referred back to her LMC midwife who will manage the rest of the pregnancy, referring back to secondary care if there are any concerns about fetal growth, diabetes control or other obstetric concerns as per the MoH Obstetric Referral Guidelines If the woman has not birthed by 40 weeks gestation, she is to be reviewed with an USS. If the woman has well controlled blood glucose levels with no obstetric concerns and wishes to await the spontaneous onset of labour, electronic foetal monitoring is performed twice weekly and labour is induced prior to 41 weeks. This plan will be clearly outlined in a letter to the LMC. - From 28/40 women will be seen 2-3 weekly or more frequently if there are concerns ie fetal growth (particularly growth restriction), hypertension, poor glucose control. - From 36/40 weekly clinic visits - It is recommended that women have a growth USS at 28/40 (or when referred if GDM) and again at 36/40 - Women to be advised to monitor fetal movements from 28/40 and to report concerns to their LMC without delay. Management in Later pregnancy: Type 1, Type 2 and GDM on insulin or metformin Timing of clinic visits: - From 28/40 women will be seen 2-3 weekly or more frequently if there are concerns ie fetal growth (particularly growth restriction), hypertension, poor glucose control. - From 36/40 weekly clinic visits - Should have a growth USS at 28/40 (or when referred if GDM) and again at 36/40. More frequent scanning considered if concerns about growth restriction or preeclampsia. - Consider HbA1c at referral around 28/40 for women with GDM then again at 36/40 to help assess the level of glucose control and to help decide whether early delivery is appropriate. - Women to be advised to monitor fetal movements from 28/40 and to report concerns to their LMC without delay. Approved by Maternity Quality Committee Next due date: April 2015 Page 5 of 13

6 Fetal Surveillance: Women with well-controlled GDM and no other pregnancy complication are not at increased risk of an intrauterine fetal death. Women with suboptimal glycaemic control and / or requiring treatment to maintain glycaemic control: Elevated fetal glucose results in increased fetal insulin production. This increases fetal growth, fat deposition and oxygen consumption. These factors put the fetus at risk of hypoxia. This is especially concerning at term and with maternal vascular disease or preeclampsia. Poor metabolic control increases the risk of neonatal morbidity and mortality but may be minimised by fetal surveillance during the third trimester. Assessment of regular fetal movements is a simple way of assessing fetal wellbeing. Any decrease or changes to the normal pattern of fetal movement will require increased monitoring. Weekly electronic foetal monitoring and two weekly USS are considered from 34 weeks onwards in women: Whose GDM is not well-controlled Fetal growth problems (significant macrosomia, growth restriction, reduced liquor) Who have other significant pregnancy complications With a history of intrauterine foetal death. NB: In specially selected cases fetal surveillance may commence at an earlier gestation and / or electronic fetal monitoring may be performed more frequently. Diet: The dietician will see the newly diagnosed woman to assess diet and provide education. Exercise: Exercise for example swimming, yoga and walking are ideal, allowing the workload to be increased safely without distress to the foetus. They should aim for about 30 minutes daily possibly split into 10 minute blocks. This is particularly effective after main meals. Women should avoid exercise in the supine position because it is associated with decreased cardiac output from pressure of the gravid uterus on the vena cava. Contraindications to exercise in pregnancy include: Pregnancy-induced hypertension or pre-eclampsia Preterm rupture of membranes Threatened preterm labour Cervical incompetence Persistent second / third trimester vaginal bleeding Intrauterine growth restriction Approved by Maternity Quality Committee Next due date: April 2015 Page 6 of 13

7 Monitoring the blood sugar levels: A BSL should be measured on waking and two hours after each meal in women with GDM or Type 2 diabetes. Diabetes nurses may contact the woman prior to her first clinic appointment to educate and start testing of BSL. Women with Type 1 will test before every meal as well as 2 hours after, plus during the night and before exercise as instructed. Two criteria should be met to assure that the degree of glycaemic control is adequate to prevent complications such as macrosomia and fetal hypoxia: The fasting BSL should be mmol/l The two hour post prandial BSL should be 4-6.5mmol/L. Initiation of medical therapy: Treatment should be initiated when the fasting BSLs are >5.5 mmol/l and the two hour post prandial BSLs are >6.5 mmol/l on at least 10% of the recordings despite dietary change. The choice of therapy is made by the physician in conjunction with the Obstetrician (considering factors such as fetal growth). Insulin: The type of insulin and dose are individualised to each woman. Adjustments in the doses are based upon the results of BSL monitoring which is documented in the record book by the woman and down-loaded from their glucose meter. Insulin resistance increases as the pregnancy proceeds therefore requiring an increase in insulin dose. Metformin: If the fasting BSL is >6 it is unlikely that metformin alone will be adequate to manage blood sugars. Women need to be aware of gastrointestinal symptoms. Metformin should not be used if there are concerns of inadequate fetal growth or placental insufficiency as it may prevent adaptive responses to placental insufficiency. Metformin acts by improving the body s sensitivity to the insulin produced by the pancreas and also injected insulin. Metformin doesn t cause hypoglycaemia Approved by Maternity Quality Committee Next due date: April 2015 Page 7 of 13

8 Timing and Mode of Delivery Timing of delivery is discussed with consideration of diabetes control, macrosomia and other obstetric factors ie PET. Accuracy of EDD also needs to be taken into consideration especially for those women booking late in pregnancy. There is no evidence supporting induced delivery before 40 weeks in women with GDM who are well controlled with diet and with a normally grown baby and no other complications ie hypertension, PET, macrosomia >90 th centile, maternal age >40 yrs. Consideration is given to an anaesthetic consultation if this has not previously been organised. Decisions regarding the timing and mode of birth are made on a case by case basis after consultation with the obstetric consultant. This decision will balance the foetal risks including macrosomia, shoulder dystocia, birth trauma, IUGR, IUD and prematurity, as well as the maternal factors such as hypertension, birth trauma and caesarean section. Indications for delivery before 39 weeks gestation include poor glycaemic control and some foetal abnormalities, include macrosomia. Women with good glycaemic control and no other pregnancy complication should ideally give birth between weeks gestation. LMC s should be informed of planned delivery time (even if under secondary care) as midwifery care can be negotiated between LMC and DHB midwives Steroids: Consideration as to whether steroids are given prior to elective caesarean section will be dependent on gestation. This will need to be planned in conjunction with the endocrine team and delivery suite as steroids will raise blood sugars usually increasing about 8 hours after the dose and may require insulin infusions or alterations in insulin doses. References: ADHB guideline Diabetes In Pregnancy 2012 American Diabetes Association. (2002). Preconception care of women with diabetes. Diabetes Care, 25 (s). pp Capital and Coast District Health Board. (2010). Gestational diabetes: Antenatal fetal surveillance, delivery and postnatal care. Policy No. W + CHD OB AL-04 Carr, C. A. (2001). Evidence based diabetes screening during pregnancy. Journal of Midwifery and Women s Health. 46, pp Approved by Maternity Quality Committee Next due date: April 2015 Page 8 of 13

9 Crowther, C. A., Hiller, J. E., Moss, J. R., McPhee, A. J., Jeffries, W. S., Robinson, J. S. (2005). Australian carbohydrate intolerance study in pregnant women (ACHOIS) trial group. Effect of treatment of gestational diabetes mellitus on pregnancy outcomes. New England Journal of Medicine. 352: Cundy T, Gamble G, Townend K, Henley PG, Macpherson P, Roberts AB. Perinatal mortality in type 2 diabetes mellitus (2000). Diabet Med. 17: 33-9 Gestational Diabetes Mellitus in New Zealand Technical Report March 2007 from the Gestational Diabetes Mellitus Technical working Party. Facillitators: David Simmons, Australian Diabetes in Pregnancy Society and Norma Campbell, New Zealand College of Midwives. Hutt Valley District Health Board (2010). Antenatal Diabetes Protocol. McAra-Couper, J., & Hunter, M. (2010). Is LSCS a normal delivery in the 21 st century? O&G Magazine. Birth, 12 (4) Nicholson, W., Fox, H., Fleisher, L., Powe, N. (2005). Screening for gestational diabetes mellitus: A decision and cost-effectiveness analysis of four screening strategies. Diabetic Care. 28 (6) Poyhonen, M., Teramo, K., Kaaja, R., Hiilesmaa, V. (2005). 50g oral glucose challenge test combined with risk factor-based screening for gestational diabetes. European Journal of ObstetGynaecol Reproductive Biology. 121 pp Rowan, J., Hague, W., Gao, W., Battin, M., and Moore, P., for the MiG Trial Investigators (2008). Metformin versus Insulin for the Treatment of Gestational Diabetes. N Engl J Med, 358: Screening, diagnosis and management of Gestational Diabetes in New Zealand: A clinical practice guideline draft version. University of Auckland 2013 Appendices Appendix 1: Flowchart Screening for Diabetes in Pregnancy Appendix 2: Management of hypoglycaemia BSL of less than 4 mmol/l Appendix 3: Blood glucose & insulin chart for ante and postnatal monitoring Approved by Maternity Quality Committee Next due date: April 2015 Page 9 of 13

10 Appendix 1: Screening for Diabetes in pregnancy Flowchart At booking does your woman have any of the following? Previous GDM Previous macrosomia Age over 40 yrs Morbid obesity (Indian/Asian BMI 32, Polynesian BMI 37, everyone else BMI 35) PCOS Two 1 st degree relatives with diabetes Glycosuria On antipsychotic medication or prednisone NO YES High risk of undiagnosed diabetes Obesity? Indian/Asian BMI Polynesian BMI Everyone else BMI Do HbA1c at 1 st visit if <12/ refer discuss with team NO YES 41 GDM GTT at wks Fasting glucose 5.5 or 2hr 9 Some will Have Pre-existing Diabetes 50g Glucose Challenge at wks Fasting glucose < 5.5 and 2 hr < 9.0 GTT at wks Fasting glucose 5.5 or 2hr 9 Refer to HVDHB Secondary Care/AND clinic Approved by Maternity Quality Committee Next due date: April 2015 Page 10 of 13

11 Appendix 2: Management of hypoglycaemia - BSL of less than 4 mmol/l: Hypoglycaemia is a BSL outside the lower limit of the woman s target range, typically less than 4.0mmol/L that may or may not be associated with symptoms such as paleness, sweating, hunger or nausea, trembling and palpitations, irritability, a personality change, drowsiness, fitting or coma. Pre-packaged hypoglycaemia treatment kit Pre-packaged hypoglycaemic treatment kits for oral treatment of the conscious patient are available in all wards. Each kit consists of a white plastic container containing La Vita tablets, hypofit sachets and jellybeans. Written instructions for using the hypoglycaemic treatment kit are enclosed in the kit. If the woman is conscious and not nil by mouth Hypoglycaemia is defined as a blood sugar level below 4 mmol/l. It should be treated immediately at the onset of symptoms or if the BSL is less than 4 mmol/l without symptoms. (NB: women with longstanding diabetes may have no symptoms despite being hypoglycaemic). Check the BSL first. If it is less than 4 mmol/l or the woman is symptomatic follow the three-step treatment: 1. Give a simple carbohydrate: 3-4 Vita tabs or 2 3 teaspoons sugar in water or 100ml sweet drink / fruit juice 2. Recheck BSL after 5 10 minutes and repeat the above prn. 3. Once the BSL is greater than 4 mmol/l give complex carbohydrate: 1 sandwich or 3 crackers and cheese or 3 plain biscuits with a glass of milk Recheck the BSL after 20 minutes. The diabetic team should be informed the next working day so that appropriate alterations to the woman s diabetes therapy can be made. Do not withhold subsequent diabetes tablets or insulin but consider reducing the dose (if insulin is withheld, hyperglycaemia will inevitably ensue and in particular, women with Type 1 diabetes can rapidly develop a potentially life threatening diabetic ketoacidosis within a few hours). The BSL should ideally be greater than 4 mmol/l during the daytime and greater than 6-7 mmol/l overnight. If the BSL is still below 4 mmol/l after giving the glucose Approved by Maternity Quality Committee Next due date: April 2015 Page 11 of 13

12 solution 3 times, summon the Obstetric SHO / Registrar for medical assistance. The Diabetes team should also be informed the next working day so that appropriate alterations to the woman s diabetes therapy can be made. Ascertain cause of hypoglycaemia if possible Adjust diabetes tablet or insulin dose, diet, activity as appropriate Test the woman s BSL according to the advice of the specialist, registrar or diabetes nurse clinician. Ensure that the woman can manage her usual diet. Note: Review current knowledge, provide further management and education as necessary or refer to inpatient diabetes nurse. If the woman is unconscious or nil by mouth Do not attempt to administer food or liquids due to risk of aspiration to the lung. Place the woman in the recovery position. Summon the Obstetric SHO or Registrar for immediate assistance. An intravenous cannula must be inserted immediately (if not already present). 1. Give a simple carbohydrate IV Dextrose 100mls of 10% dextrose intravenously as a slow push or 50mls of 20% dextrose intravenously. If no intravenous cannula, give IM glucagon 1mg NGT 100ml sweet fluid 2. Recheck BSL after 5 10 minutes and repeat the above prn 3. Once >4.0mmol/L give complex carbohydrate IV fluid with 6 10gm dextrose per hour Enteral feed containing carbohydrates Approved by Maternity Quality Committee Next due date: April 2015 Page 12 of 13

13 Appendix 3: Blood glucose & insulin chart for ante and postnatal monitoring Time Type Of Medication Date BSL Oral Hypoglycaemia Ketones Medication Dose Insulin Time Type Of Medication Date BSL Oral Hypoglycaemia Ketones Medication Dose Insulin Time Type Of Medication Date BSL Oral Hypoglycaemia Ketones Medication Dose Insulin Time Type Of Medication Date BSL Oral Hypoglycaemia Ketones Medication Dose Insulin Time Type Of Medication Date BSL Oral Hypoglycaemia Ketones Medication Dose Insulin Approved by Maternity Quality Committee Next due date: April 2015 Page 13 of 13