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The management of pregnant women with diabetes

All women with pre-existing diabetes

  • Pre-pregnancy counselling should be offered to all women with diabetes at all possible times
  • Women on oral hypoglycaemic agents (apart from metformin) or whose HbA1c is above normal should be started on insulin before conception or in unplanned pregnancy as soon as pregnancy is confirmed
    – women with HbA1c>10% (86 mmol/mol) should be advised to avoid getting pregnant
  • A 5 mg dose of folic acid should be started (ideally 3 months) pre-conception and continued to 12 weeks gestation
  • Women should be given healthy eating advice that is in line with that given to all women with diabetes
  • As early as possible the woman with diabetes should be seen in a combined clinic by a team including an obstetrician with a special interest in diabetes and pregnancy, a physician, a specialist diabetes dietitian, a specialist diabetes nurse and a specialist midwife
    • the woman (and her partner) should be included as members of the team and given sufficient appropriate information to make choices about her care
  • Blood glucose levels should be monitored frequently and insulin adjusted accordingly:
    • goals for self-monitored blood glucose levels should be set jointly with the woman
    • levels of HbA1c should be below 6.1% (43mmol/mol), but for women at risk of hypoglycaemia 7.5% (56mmol/mol)
      • capillary whole blood glucose:
        before meals <5.9 mmol/l
        1 hour after meals <7.8 mmol/l
      • capillary plasma glucose:
        before meals 4.4–6.1 mmol/l
        1 hour after meals <8.6 mmol/l
    • all women diagnosed with pre-existing diabetes, or with gestational diabetes, should test glucose levels before breakfast and 1 hour after every meal during pregnancy
  • A woman on an established insulin regimen should be able to continue. Some medication should not be taken during pregnancy, so it may be necessary to change to an alternative
  • The risk of hypoglycaemia is increased, so those close to the woman with diabetes should be instructed in its recognition, management and treatment; partners should be supplied with and taught to use glucagon
  • Diabetic ketoacidosis (DKA) is particularly dangerous in pregnancy, so the woman should be prescribed and instructed in the use of ketone testing strips; the emphasis should be on prevention
  • If DKA is suspected the woman must be admitted to level 2 critical care
  • A detailed retinal examination should be performed on all patients during the first trimester and each trimester for those with retinopathy to detect and treat any accelerated retinopathy
  • An ultrasound measurement of the foetal crown-rump length should be made in the first trimester to confirm the duration of pregnancy
  • A detailed 'anomaly' ultrasound should be performed between 18 and 22 weeks and analysed by an experienced doctor
  • Foetal growth and amniotic fluid volume should be assessed every 4 weeks from 28 to 36 weeks
  • Foetal well-being should not be assessed before 38 weeks
  • If delivery is indicated at <36 weeks, corticosteroids should be administered to prevent neonatal respiratory distress syndome and additional insulin given to prevent severe maternal hyperglycaemia and ketoacidosis
  • If pregnancy continues beyond 38 weeks, the woman should be offered induction of labour or C-section if the healthcare team think it is the best option (this is to prevent stillbirth)
  • With good diabetes control, it may be possible to prolong pregnancy to 39 or 40 weeks to achieve a vaginal delivery
  • Postpartum:
    • most mothers will need advice about their pre-pregnancy dose of insulin
    • breastfeeding should be encouraged
      • women should be warned they are more susceptible to hypoglycaemia if breastfeeding; extra monitoring should be performed and extra carbohydrate taken to prevent this
  • Metformin and glibenclamide can be given while breastfeeding:
    • neonatal blood glucose should be measured 2–4 hours after birth (not immediately)
    • if the baby’s blood glucose level, stays below 2?mmol/l for two consecutive tests of if s/he is not feeding properly, the baby may be fed through a tube, syringe, or drip
    • mothers should be seen 6 weeks postpartum by their GP or at a combined diabetes clinic
    • mothers should have the opportunity to be seen by a multidiciplinary team, and be offered contraceptive advice

Gestational diabetes

  • At the booking appointment screening for gestational diabetes will be made using risk factors
    • body mass index >30 kg/m2
    • previous macrosomic baby weighing 4.5 kg or more
    • previous gestational diabetes
    • first degree relative with diabetes
    • family origin with high prevalence of diabetes—South Asian, Black Caribbean, Middle Eastern
  • If any one factor is present, a 2 hour 75 g oral glucose tolerance test should be performed (OGTT)
  • Diagnosis should be made if fasting venous plasma glucose is >7.0 mmol/l or fasting venous plasma glucose is <7.0 mmol/l but venous plasma glucose is >7.8 mmol/l 2 hours after a 75 g glucose load
  • Glucose tolerance changes during pregnancy, so the gestation at which the diagnosis was made should be recorded; if made in the third trimester the clinician should be cautious about the clinical implications of impaired glucose tolerance
  • Obstetric management should be individualised; induction or C-section should be offered at 38 weeks gestation
  • Dietary and lifestyle advice should be provided for all women with GDM by a registered dietitian
    • the woman should be advised to choose, where possible, carbohydrate from low glycaemic index (GI) sources, lean proteins including oily fish, and a balance of poly- and monounsaturated fats
    • the diet should give adequate calories and nutrients to meet the needs of pregnancy and be consistent with the maternal blood glucose goals that have been established
    • appropriate exercise should be encouraged
  • Blood glucose should be self-monitored daily with frequency depending on treatment
  • Hypoglycaemic agents may include insulin or oral hypoglycaemic agents (metformin and glibenclamide)
  • If fasting glucose levels exceed 5.9 mmol/l or pregnancy progresses past term there should be increased obstetric surveillance because of the risk of stillbirth
  • Blood pressure and urine protein monitoring are needed to detect hypertensive disorders
  • If fasting glucose levels exceed 5.9?mmol/l or pregnancy progresses past term there should be increased obstetric surveillance because of the risk of stillbirth
  • Blood pressure and urine protein monitoring are needed to detect hypertensive disorders
  • Assessment of foetal growth by ultrasonography may help identify a foetus that can benefit from maternal insulin therapy; this is particularly useful in the early third trimester
  • If foetal macrosomia is present, delivery during the 38th week is recommended unless there are other obstetric considerations
  • Postpartum:
    • hypoglycaemic agents can usually be stopped immediately
    • women should be referred to the specialist diabetes team
    • they should be advised of the increased risk of type 2 diabetes, and how it can be reduced, and the increased risk of GDM in subsequent pregnancies
    • they should be advised to make appropriate dietary changes early in any subsequent pregnancy, preferably before conception
    • they should be encouraged to take advantage of well woman clinics and attend for regular health checks
    • women with GDM
      • should have their blood glucose level checked before being discharged into community care to ensure that she is normoglycaemic
      • should have a fasting glucose test at their 6 weeks post natal check and annually from then on
      • who are planning another pregnancy, should be offered early self-monitoring of blood glucose levels, with an OGTT at 16–18 weeks, repeated at 28?weeks if the first test was normal

full guidelines available from…
Diabetes UK, 10 Parkway, London NW1 7AA (Tel –020 7424 1000)
http://www.diabetes.org.uk

Diabetes UK. Recommendations for the management of pregnant women with diabetes (including gestational diabetes). 2003, updated June 2010
First included: February 2002, Updated: February 2004, June 2004, Februay 2007, October 2007, June 2010.