DIABETES IN PREGNANCY

1. DIABETES IN PREGNANCY Matthew

2. Definition-1 • Diabetes may be characterized by peripheral insulin resistance, relative insulin deficiency, obesity and the development of vascular, renal and neuropathic complications • Gestational diabetes is characterized by carbohydrate intolerance that is seen or first recognized in the current pregnancy. But 15% of women may persist with diabetes long after delivery.

3. Types • TYPE I : insulin dependent, juvenile onset, insulin dependent; prone to ketoacidosis if insulin is withheld. • Multifactorial ,genetic predisposition with associated viral infections and autoimmune responses of the islet cells • TYPE 2 : non-insulin dependent. disorder has strong hereditary association, insulin resistance , decreased affinity of insulin receptors.

4. Pathogenesis • Effects of deficiency of insulin secretion after carbohydrate diet are: under-utilisation of glucose by skeletal muscle, adipose tissue and the liver resulting in postprandial hyperglycemia • Low insulin predisposes to glycogenolysis and gluconeogenesis. • Renal threshold is exceeded and there is glycosuria , osmotic diuresis and total body water and electrolyte depletion

5. Derangement of lipid metabolism • Excessive lipolysis and enhanced ketogenesis. • Increased mobilization of free fatty acids from adipose tissue leads to increased plasma levels of free fatty acids • These are oxidised to ketoacids ; beta-hydroxybutyrate, acetoacetate. Metabolic acidosis occurs. • Increased hepatic production and reduced peripheral clearance of VLDL

6. EFFECT ON AMINO ACIDS • Decreased uptake of amino acids by skeletal muscles, decreased protein synthesis and proteolysis. • Increased urinary excretion of nitrogen • Blood levels of branched-chain amino acids leucine, isoleucine, and valine increase. • Alanine and glycine are released by muscle to contribute to gluconeogenesis

7. MATERNAL COMPLICATIONS • Recurrent infections • PET • Polyhydramnios • Diabetic ketoacidosis • Preterm labour

8. FETAL COMPLICATIONS • Recurrent pregnancy losses • Congenital abnormalities • Macrosomia • Hypoglycaemia • Respiratory distress syndrome • Hypocalcaemia • Polycythaemia

9. Women at risk • History of diabetes • Recurrent pregnancy losses • History of congenital abnormalities • Macrosomia • Stillbirth • Obese • Recurrent candidiasis

10. Screening tests • FBS • 2 hr postprandial (OGTT) using 75g glucose • Random blood sugar • 1 hr after 50g of glucose ingestion

11. INDICATIONS FOR OGTT • Family history • Obesity • Stillbirths and/fetal congenital abnormalities • Macrosomia • Persistent glycosuria • Previous history of gestational diabetes • Polyhydramnios • Maternal age of 35yrs and above

12. CRITERIA FOR DIAGNOSING DIABETES • 75g glucose for oral ingestion • Venous blood taken • Normal value: FBS < 6mmol/l , impaired glucose tolerance 6-8 mmol/l, diabetes > 7 mmol/l • 2 hr postprandial: normal < 8 mmol/l, impaired glucose tolerance 8-11 mmol/l, diabetes >11mmol/l

13. OGTT • Patients with impaired glucose tolerance may be retested later in pregnancy • If the FBS is very high, then the glucose load can precipitate ketoacidosis

14. Management • Pre-pregnancy counselling • Early booking • Multidisciplinary approach to management • Prenatal diagnosis necessary • Control of blood glucose • Frequent visits • Rule out infections • Rule out other complications in mother and fetus

15. Lab investigations • Blood glucose profile • Glycosylated HB • Ultrasound for fetal growth and well being • FBC • Urine M/C/S • BUE and Creatinine.

16. Diet • First line of management for gestational diabetes. Oral hypoglycaemic drug such as Metformin and/or Insulin added when this fails. • 30 kcal/kg/day • Usually 1800 kcal/day and 1600kcal for the obese • About 50-60% carbohydrates (only high fibre types), 30% fats, and 20% proteins. • Aim at FBS 5.8 mmol/l and 2hr postprandial 6.7 mmol/l

17. Insulin administration • A mixture of soluble and intermediate insulin required • Start with 0.7miu/kg • 2/3 given in the morning and 1/3 in the evening • 1/3 morning dose as soluble, 2/3 as intermediate in the morning • Same fraction in the evening. • Six point sugar profile advocated during stabilization

18. Oral hypoglycaemics • Glyburide (Metformin) is used for gestational diabetes and non insulin dependent in pregnancy. • Other hypoglycemic agents (diaonil) may cause congenital abnormality thus should be avoided

19. Delivery • Delivery usually by 38 to 40 weeks if there are no complications. Do not exceed 40 weeks. • Aim at vaginal delivery unless there are contraindications • If elective delivery is necessary confirm pulmonary maturity. Steroids may be given to mature the lungs

20. Induction of labour • Check the gestational age • Check the indication , blood sugar, BP etc • Check the lie, presentation and fetal weight • Use prostaglandins for ripening the cervix • Avoid prolonged labour

21. Labour and Delivery • Use oxytocin for augmentation • CTG for fetal monitoring very useful • ARM to be done late to prevent infections • Hrly blood glucose check, • Broad spectrum antibiotics,

22. Labour and delivery • GKI may be necessary ; Sliding scale • Regular fetal monitoring with CTG is essential • Paediatric team should be involved in resuscitating the neonate • Obstetric team should be conversant with managing shoulder dystocia

23. Elective c/s • Ensure gestational age is at least 39 weeks • Check the FBS • First delivery in the morning • Glucometer should be available for hourly estimation of blood sugar levels • Anaesthetists and paediatrician should be consulted before.

24. Puerperium • The blood sugar level should be checked before the next insulin dose is given if necessary • Breastfeeding is encouraged • Avoid infections • Avoid DVT • Counsel for family planning • Counsel for Paps smear

25. Interesting questions • Is there a role for oral hypoglycaemic agents in pregnancy? • Is there a role for preconceptional counselling? • Is there a role for continuous subcutaneous insulin infusion during pregnancy? • What fetal assessment is appropriate in women with pregestational diabetes mellitus?

26. Interesting questions • When and how should delivery occur? • How should glucose control be managed during labour? • Are special postpartum considerations necessary?

27. Recommendations-1 • Suspected macrosomia not an indication for induction because induction does not improve maternal or fetal outcomes • Antenatal monitoring should include fetal movements counting, non-stress test, biophysical profile, doppler studies and contraction stress test? • Adequate maternal sugar control to prevent spontaneous abortions, fetal malformations, fetal macrosomia, intrauterine fetal death

28. Recommendations-2 • Patients and families should be taught how to respond to hypoglycaemia • Pre-conceptional counselling for women with pre-gestational diabetes has been reported to be beneficial and cost-effective and should be encouraged • To prevent traumatic delivery, CS should be done for weight more than 4kg