gestational diabetes Flashcards
RFs for gestational diabetes
- BMI of > 30 kg/m²
- increased maternal age
- previous macrosomic baby weighing 4.5 kg or above
- previous gestational diabetes
- first-degree relative with diabetes
- family origin with a high prevalence of diabetes (South Asian, black Caribbean and Middle Eastern)
when do we screen for gestational diabetes
women who’ve previously had gestational diabetes:
women with any of the other risk factors
when should women w other risk factors be tested (weeks)
booking offered an OGTT at 24-28 weeks
when should women who previously had gestational diabetes be tested
ral glucose tolerance test (OGTT) should be performed as soon as possible after booking/ 16-18 weeks and at 24-28 weeks if the first test is normal.
alternative - early self-monitoring of blood glucose is an alternative to the OGTTs
diagnostic threshold for gestational diabetes
Blood glucose targets
fasting glucose is >= 5.6 mmol/l
2-hour glucose is >= 7.8 mmol/l
Pre-meal < 5.3 mmols 1hr post < 7.8mmols 2hr post < 6.4mmols
risks to foetus as a result of GDM
macrosomia shoulder dystocia respiratory distress syndrome neonatal jaundice polycythaemia hypoglycaemia obstructed labour
pre-eclampsia miscarriages congenital anomalies preterm birth c section perinatal death
pathophysiology of glucose in pregnancy
increase in insulin resistance
due to placental producing human placental lactogen (HPL)
pancreas increase insulin production
HPL increase breakdown of lipids
oestrogen increases maternal hepatic gluconeogenesis
if pre pregnant your reisistant to insulin then youll be more resisitnat during pregnancy therefore mroe glucose in body more passing via placenta to baby
risk of congential abnormalities in preexisting DM
embryo w hyperglycaemia increases oxidative stress leads to dysregulation of gene expression and excess apoptosis of organs - CNS, CVS
VSD
transposition of great vessels
tetralogy of fallot
persistent fetal circulation
truncus arteriosus
CNS defects
- encephaly
- spina bifida
- hydrocephaly
- minomenigocele
NT defect char collect in vertebral colum failure closure of spinal NT malformation of vertrabeal column and spinal cord
meninges and spinal cord visible
caudal regression/sacral agenesis
- abormal fetal development of lower spine
- linked w insufficient folic acid
medical MX summary of pre-exisitng diabetes
blood glucose targets
US scans
- weight loss for women with BMI of > 27 kg/m^2
- stop oral hypoglycaemic agents, apart from metformin, and commence insulin
- folic acid 5 mg/day from pre-conception to 12 weeks gestation
- aspirin 75mg/day from 12 weeks until the birth of the baby, to reduce the risk of pre-eclampsia
- detailed anomaly scan at 20 weeks including four-chamber view of the heart and outflow tracts
tight glycaemic control reduces complication rates
treat retinopathy as can worsen during pregnancy
Blood glucose targets :
Pre-meal < 5.3 mmols
1hr post < 7.8mmols
2hr post < 6.4mmols
Ultrasound Scans
- Dating by 12 weeks
- Detailed / Cardiac 18-22 weeks
- Growth & Liquor Volume 28/32/36 weeks
ANC 1-2 weekly (based upon control/risk factors)
Repeat retinal assessment at 28 weeks (if normal in first trimester)
planning delivery in pre-existing DM
planning delivery in GDM
Deliver 37-38+6 weeks
IOL : 37-38+6 weeks
Elective CS : 38-39 weeks
Deliver 39-40+6 weeks : NICE (2015)
IOL : 39-40 weeks
Elective CS : >39-40+6 weeks
how are women w GDM risk factors are screened
75g load rapilose gel
Timing?
16-18 weeks (prev GDM / high risk)
26-28 weeks (other risk factors e.g FH/Ethnicity)
Diagnosis ‘STEPS’
Fasting > 5.6mmols (NICE 2015)
2hr BG > 7.8mmols
postnatal GDM Mx
STOP all TREATMENT & BG MONITORING at delivery
FBG at 6-13 weeks
HBA1c at 13 weeks & yearly thereafter (Risk T2DM)
Lifestyle advice
Contraception and need for pre-conception care in future
Mx of GDM
1) newly diagnosed women should be seen in a joint diabetes and antenatal clinic within a week
2) women should be taught about self-monitoring of blood glucose
-> advice about diet (including eating foods with a low glycaemic index) and exercise should be given
-> explained the problems to the continuation of the pregnancy if BMs are not well controlled
3) fasting plasma glucose level is < 7 mmol/l
- diet and exercise should be offered
if glucose targets are not met within 1-2 weeks GO TO METFORMIN
4) if glucose targets are still not met insulin should be added to diet/exercise/metformin
gestational diabetes is treated with short-acting, not long-acting, insulin
5) if at the time of diagnosis the fasting glucose level is >= 7 mmol/l insulin should be started
6) if the plasma glucose level is between 6-6.9 mmol/l, and there is evidence of complications such as macrosomia or hydramnios, insulin should be offered
7) glibenclamide should only be offered for women who cannot tolerate metformin or those who fail to meet the glucose targets with metformin but decline insulin treatment
Ultrasound Scans
- Dating by 12 weeks
- Detailed 20+ weeks
- Growth & LV: 3-weekly >26 weeks (GROW)
ANC 1-4 weekly (based upon control/risk factors)
arrange a date for elective C section to avoid an obstructed labour
fetal complications of GDM
- intrauterine death
- miscarriage
- hypoxia
- congenital abnormality especially cardiac
organomegaly - macrosomia, hypoglycaemia
- risk of baby developing obesity later
