Lec19 Maternal hyperglycaemia during pregnancy Flashcards
What effect does maternal hyperglycaemia have on the foetus?
Very bad for the foetus and significant morbidity affecting the baby all its life
What can you do to improve the outcome for the foetus?
Improve the maternal blood glucose
Why does diagnosing maternal hyperglycaemia matter?
It is an opportunity to prevent:
Significant morbidity to the foetus
Consequences of the maternal hyperglycaemia will affect the foetus “from the uterus to the grave”
Exacerbation of the type 2 DM and obesity epidemic
Future type 2 DM in the mother - through educating her
In the antenatal clinic there are two groups of women, what are they?
Women with normal glucose tolerance
Women with abnormal glucose tolerance
Out of the women in the ANC with abnormal glucose tolerance, what are the two groups within them
Women with known diabetes or IGT
Women with unknown diabetes/ IGT
In pregnancy, IGT is the same as:
diabetes
What happens to women with known Type 1 DM when they get pregnant?
They go to specific clinics
When is gestational diabetes diagnosed?
Following a newly found abnormal GTT after the 1st trimester of pregnancy
What happens to insulin sensitivity during the 1st trimester?
The mother is slightly more sensitive to insulin so her glucose will go down but then up after the 1st trimester
What is the WHO criteria definition of gestational diabetes?
Fasting glucose >/= 5.6mmol/l
2 hour GTT >/= 7.8mmol/l
What is the main problem of maternal hyperglycaemia during pregnancy?
It can cause serious problems for the foetus
Describe the key events in the 1st trimester:
Organogenesis - carefully design essential components
avoid mistakes - teratogenesis
Placenta - construct and programme the placenta
key organ in pregnancy
if the placenta is incorrectly formed –> more likely to get pre-eclampsia and delivers excess glucose
Describe what happens in the 2nd trimester:
Further complex development and linkage
Describe what happens in the 3rd trimester
Accelerated growth - more glucose is delivered to the baby to facilitate the accelerated growth but with a malformed placenta - excess glucose will be delivered to the placenta
Excess fat is deposited around the organs in the abdomen - visceral fat
What is the maternal metabolism as pregnancy progresses?
Early pregnancy = facilitated anabolism
Later pregnancy = facilitated catabolism
What does facilitated anabolism mean?
Increased insulin sensitivity
Glucose concentration slightly lower
Increased maternal energy stores for accelerated growth periods
What does facilitated catabolism mean?
Increased insulin resistance
Increased transplacental passage of nutrients
Which leads to rapid foetal growth
What consequences are there for the foetus from 1st trimester maternal hyperglycaemia?
Foetal malformation
Fuel mediated teratogenesis
Give examples of foetal malformation:
Hydrocephalus
Meningomyelocoele - neural tube defects more common in hyperglycaemic mothers than in the general population
Central cyanosis in congenital heart disease
Single ventricle and sacral dysgenesis
Renal agenesis
Even in a woman with normal HbA1c the risk of malformations is increased above what percentage of the background population?
2%
How do you prevent foetal malformation in hyperglycaemia of pregnancy?
Pre pregnancy counselling for known diabetes
Lifestyle modification
Good diabetes control in 1st trimester
Intensive glucose monitoring
Folic acid 5mg/day preconception - higher dose than normal
Get rid of oral hypoglycaemic agents and put mother on insulin
Why do you put the mother on a higher dose of folic acid?
Because higher dose shown to reduce chances of congenital defects
What is the ideal HbA1c before conception, but certainly once she knows she’s pregnant?
Down to 6%
How do you identify unknown cases of diabetes/ IGT?
By checking women with risk factors
What are the risk factors?
Previous gestational diabetes Obesity Polycystic Ovarian Syndrome FHx T2DM High risk racial groups e.g. African, South east asian
What are problems that may arise in the third trimester?
Macrosomia & associated problems
Pre-eclampsia
Foetal or neonatal death
What are the associated problems of macrosomia?
Shoulder dystocia Difficult birth Breathing problems Jaundice Hypoglycaemia
What is the risk of shoulder dystocia?
The baby’s shoulder gets stuck during labour and freeing it can cause axillary nerve damage to the baby
These babies also get hypoglycaemia frequently
Compared to normoglycaemic women, babies born to hyperglycaemia women have higher incidence of:
Obesity Insulin resistance Type 2 diabetes Dyslipidaemia Hypertension Vascular disease
When do NICE guidelines say you should screen mothers with risk factors?
At 26 weeks
What is the vicious cycle of hyperglycaemia?
If the grandmother was hyperglycaemic, she was probe hyperglycaemic during pregnancy with the mother, the mother probably suffered with obesity and hyperglycaemia all her life and therefore when she has a baby, that baby also likely to be obese and hyperglycaemic
Treatment of any pregnancy hyperglycaemia?
Good maternal glucose control through intensive blood glucose monitoring
Fasting & 1 hour post prandial minimum
Appropriate nutrition
Reasonable exercise
Ultrasound monitoring of foetal abdominal girth - weekly from 28 weeks
Maternal observation of foetal movements
What would be the drug treatment pre-pregnancy/ 1st trimester?
Basal bolus insulin regimen
What would be the drug treatment in “gestational diabetes”
Metformin Basal insulin Basal bolus insulin Glibenclamide Sulfonylureas are used when women don't want to take insulin
What is advised postpartum?
Breastfeed for as long as possible - breast feeding reduces risks for mother an child & allows mother to reduce weight
Women who lactated from 6-12 months or 12 months or longer had:
half the risk for diabetes
Specific GDM management postpartum:
Screen for diabetes 12 weeks pp HbA1c +/- fasting glucose or GTT Lifestyle advice Advice re next pregnancy Annual glucose screening Combined OCP after 6 weeks/ Mirena intrauterine system
The progesterone pill is more likely to cause what in GDM mothers?
Insulin resistance
