Obesity and Gestational Diabetes Mellitus

Question 1

What are the risks to a pregnant woman of obesity?

Answer 1

• Gestational diabetes
• Pre-eclampsia
• Higher mortality
• Lowered fertility/recurrent miscarriage
• Thromboembolism

Question 2

What problems are more likely in a foetus if maternal obesity is present?

Answer 2

• Macrosomia
• Congenital abnormalities (exomphalos, heart defects)
• Neural tube defects (less folate responsive, more likely to be missed in screening)

Question 3

What is the association between gestational weight gain and post-partum weight?

Answer 3

• Some GWG may be retained post-pregnancy if greater than recommendations.
• Less GWG than recommended was associated with a return to baseline

Question 4

What are the effects of pregnancy on diabetes? Of diabetes on pregnancy?

Answer 4

• Effects of pregnancy on diabetes
  
  • Exacerbation of nephropathy (screen with 24 hour urine), retinopathy (consider pre-treatment), macrovascular disease, autonomic neuropathy (gastroparesis, orthostatic hypotension)
  • Increased insulin requirement
  • DKA, hypo likelihood increased
  • May unmask subclinical T2D - 30-50% patients will develop it within 25 years
• Effects of diabetes on pregnancy
  
  • Pre-eclampsia
  • Miscarriage

Question 5

What percentage of people who develop gestational diabetes will go on to develop T2D within the next 25 years?

Answer 5

• 30-50% patients will develop it within 25 years

Question 6

What are the foetal problems associated with gestational diabetes?

Answer 6

• Polyhydramnios
• Congenital abnormalities (cardiac, neural tube, cleft lip, caudal regression)
• Macrosomia
• IUGR (especially if macrovascular disease)
• FDIU
• Prematurity
• Shoulder dystocia

Question 7

What are neonatal and intra-partum problems common to women with gestational diabetes?

Answer 7

• Neonatal problems
  
  • Hypoglycaemia/calcaemia/magnesaemia, polycythaemia, hyperbilirubinaemia, RDS
• Pregnancy/labour problems
  
  • Higher operative delivery rates
  • Increased infection risk
  • Increased PPH risk

Question 8

Which diabetes medications are safe to continue during pregnancy?

Answer 8

• Insulins are safe to continue
• Metformin is probably safe to continue
• Other are not (sulphonylureas, statins, glitazones)

Question 9

What changes need to be made to routine antenatal care for a woman with gestational diabetes?

Answer 9

• Frequent MDM visits (obstetrician, endocrinologist, diabetes educator, dietician)
• Maintain BGLs (4-5.5 fasting, less than 7 at 2 hours)
• Maintain HbA1c
• Avoid DKA/hypo
  
  • Basal-bolus insulin regime
  • Insulin requirements increase up to term
• Monitor complications e.g. protein excretion/ophthalmology review
• T1 screening recommended
• Morphology scan at 20 weeks
• Growth scans at 28 and 34 weeks

Question 10

What intrapartum considerations might you have for a woman with gestational diabetes?

Answer 10

• Aim for term, avoid post-dates
• Vaginal delivery unless macrosomic
• Regular BGL monitoring (keep within 4-7)
• If elective LUSCS, first on list, skip morning insulin
• CTG continuously
• Anticipate shoulder dystocia, watch for PPH

Question 11

In a neonate born to a woman with gestational diabetes, what would cause you to admit them to the special care nursery for further monitoring?

Answer 11

• If maternal HbA1c > 7.5%
• BGL > 8 during labour
• IV glucose during labour
• Infant unwell, preterm, macrosomic