Diseases in pregnancy

Define gestational diabetes?

The onset of diabetes or abnormal glucose tolerance for the first time during pregnancy.

What are the main effects of gestational diabetes on the foetus?

-Polyhydramnos.

-Macrosomia.

-Increased incidence of preterm labour.

How can gestational diabetes be screened for?

1) Oral glucose tolerance test (OGTT) for high risk women.

2) Oral glucose load and single blood sugar estimation 2 hours later.

3) Random blood sugar at 28 weeks gestation 2 hours after last meal. Women who have high sugar values then go on to have a OGTT.

What high risk features may result in abnormal glucose tolerance test and indicate screening with OGTT?

Name 4.

1) High maternal weight (>90th centile or BMI > 30).

2) Previous large baby (>4.5kg).

3) First degree relative with diabetes.

4) Glycosuria:

-Once before 20 weeks.

-Twice after 20 weeks.

5) Polyhydramnos.

6) Previous unexplained stillbirth or neonatal death.

7)Fetal macrosomia on ultrasound.

What is the OGTT and what values warrent further investigation?

50g glucose load in flavoured water.

Fasting values of >5.8mmol/l or 2-hour values of >7.8mmol/l require further testing.

When should oral hypoglycaemics be used to treat gestational diabetes?

Never!

in gestational diabetes, how should home monitoring take place, what levels spur one to action, and what action should that be?

-Home monitoring with electronic blood glucose kits.

-Fasting and 1hr post-meal levels should be monitored at least twice a week.

-Fasting levels <5.5mmol/l and 1hr levels <9mmol/l are fine - no treatment.

-However, if values top these cut-offs, diet should be modified - low carbohydrate diet. Ketone leves in urine should now also be monitored.

When should insulin be used in gestational diabetes? How should the foetus be monitored?

Insulin should be started when:

-Blood sugar levels are >5.5mmol/l fasting or >9mmol/l 1hr after a meal, and when carbohydrate-restricted diet has failed to control this, or

-When ketosis occurs, in which case dietry restrictions should be relaxed.

-Twice-daily short and long-acting insulins should be used.

-Monthly ultrasounds scans should be performed to check foetal growth and amniotic fluid levels.

How does gestational diabetes affect timing of delivery?

-If there is no evidence of excessive foetal growth, no polyhydramnos, no maternal ketosis, and gluocse levels are not >9mmol/l 1hr after eating or >5.5mmol/l fasting, then the pregnancy can be allowed to continue up to 42 weeks.

-Women with abnormal ultrasound scans should be induced at term (though some obstetricians induce at 38-39 weeks).

When should insulin requirements dissapear in gestational diabetes?

With the delivery of the placenta!

Are women with gestational diabetes more likely to go on to develope diabetes?

-40% of women with gestational diabetes go on to develop diabetes in the next 10-20 years. This risk doubles if they are obese.

-Gestational diabetes usually recurrs in future pregnancies, though this is not inevitable.

How should gestational diabetes be controlled in labour?

Those on insulin antenatally should have the same IV insulin and glucose regime as type I diabetics