DIABETES IN PREGNANCY
DR HUMERA NAEEM
Learning Objectives
At the end of session students should be able to:
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Define diabetes in pregnancy and its classification.
Recognize the magnitude of the problem and it’s
clinical significance
Describe risk factors in history and examination
Enlist investigations for making diagnosis.
Outline screening protocol for high risk and low risk
pregnancy
Recognize the effects of diabetes on pregnancy and
its outcome
Enlist feto-maternal complications associated with
diabetes in pregnancy.
DIABETES
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Diabetes is a disease in which the body’s
ability to produce or respond to the
hormone insulin is impaired, resulting in
abnormal metabolism of carbohydrates and
elevated levels of glucose in the blood.
Diabetes may complicate a pregnancy either
because a woman has type 1 or type 2
diabetes mellitus before pregnancy or
because impaired glucose tolerance develops
during the course of her pregnancy (GDM)
Gestational Diabetes
Gestational diabetes mellitus (GDM) is
defined as any degree of glucose intolerance
with onset or first recognition during
pregnancy.
Background
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Approximately 5% of the women have either
pre-existing diabetes or gestational diabetes.
Of women who have diabetes during
pregnancy, it is estimated that approximately
◦ 87.5% have gestational diabetes (which may or
may not resolve after pregnancy)
◦ 7.5% have type 1 diabetes
◦ the remaining 5% have type 2 diabetes.
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GDM complicates 10–15% of pregnancies
depending on the diagnostic criteria used
High-Risk Groups
Women from an ethnic group with high
rates of type 2 diabetes.
 Family history of type 2 diabetes.
 Maternal obesity.
 Previous history of GDM, large for
gestational age infant, unexplained still
birth.
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SCREENING
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Use the 2-hour 75 g oral glucose tolerance test
(OGTT) to test for gestational diabetes in
women with risk factors.
Offer women who have had gestational diabetes
in a previous pregnancy: early self-monitoring of
blood glucose or a 75 g 2-hour OGTT as soon as
possible after booking (whether in the first or
second trimester), and a further 75 g 2-hour
OGTT at 24–28 weeks if the results of the first
OGTT are normal.
Offer women with any of the other risk factors
for gestational diabetes a 75 g 2-hour OGTT at
24–28 weeks.
GLUCOSE TOLERANCE TEST
The values for diagnosis of GDM are
 Fasting glucose of 5.1 mmol/l (92 mg/dL)
and/or
 1 hour (post 75 g glucose load) of 10.0
mmol/l (180 mg/dL) or
 2 hour of 8.5 mmol/l (153 mg/dL).
RISKS/COMPLICATIONS
(more common in women with pre-existing diabetes)
MATERNAL COMPLICATIONS
 End organ damages such as
retinopathy, neuropathy, nephropathy
(in pre-excisting diabetes)
 Increased hospital visits/increased risk
of hospital admissions
 Hyper/Hypoglycemia/DKA
 Increased incidence of urinary/vaginal
infections
 Polyhydramnios/Preterm labour
 Pre-eclampsia
 Labour dystocia, difficult delivery,
perineal injuries, PPH
 Increased risk of operative delivery
 Puerperal sepsis
 Risk of developing type 2 diabetes (in
GDM)
FETAL COMPLICATIONS
 Miscarriage
 Congenital malformations (cardiac
and neural tube defects)
 Macrosomia
 The risks associated with fetal
macrosomia (increased operative
delivery, shoulder dystocia, birth
injuries, neonatal unit admission,
polycythemia, hypocalcemia,
hypomagnesemia)
 Stillbirth
 Preterm delivery
 Perinatal mortality and postnatal
adaptation problems (such as
hypoglycaemia)
INVESTIGATIONS
Other than routine antenatal investigations
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HbA1C at booking (or at diagnosis if GDM)
Daily blood glucose monitoring
Renal and retinal screening should be offered in pre
existing diabetes.
Retinal screening at booking, 16–20 weeks (if
abnormal at booking) and 28 weeks of gestation
Women with diabetes should be offered a fetal
anomaly scan at 19–20 weeks with an assessment of
the cardiac outflow tracts (fetal echocardiography at
22-24 weeks)
Serial growth scans are also recommended to assess
fetal growth and diagnose macrosomia and
polyhydramnios.
Urine dipstick to screen for UTI, proteinuria and
ketones.
Target blood glucose levels
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Advise pregnant women with any form of
diabetes to maintain their capillary plasma
glucose below the following target levels,
if these are achievable without causing
problematic hypoglycemia:
◦ Fasting: 5.3 mmol/litre (95 mg/dl) and
◦ 1 hour after meals: 7.8 mmol/litre (140 mg/dl)
or
◦ 2 hours after meals: 6.4 mmol/litre (115
mg/dl).