Diseases of the Mother in Pregnancy

Core

Gestational Diabetes

Gestational diabetes is a condition characterised by episodes of hyperglycaemia during pregnancy due to insulin resistance. However, gestational diabetes often resolves following birth. It is important to have a baseline for insulin resistance before pregnancy, because some women may be very likely to develop gestational diabetes if they are already resistant to insulin, or unable to produce adequate insulin.

Clinical implications of gestational diabetes can be serious and include:

• Increased incidence of miscarriage.
• Increased risk of congenital malformation, particularly when hyperglycaemia is present early in pregnancy. This risk is reduced with good glycaemic control.
• Increased incidence of macrosomia (a larger than normal baby). Macrosomia increases risk of shoulder dystocia which is an obstetric emergency. Shoulder dystocia is when the shoulders of the baby get stuck in the birth canal. This can lead to significant fetal morbidity and mortality. There can also be a risk to the mother of post partum haemorrhage and perineal tears. Brachial plexus injury to the baby is also possible.
• Increased risk of gestational hypertension and pre-eclampsia.
• Increased risk of developing Type 2 Diabetes Mellitus (T2DM) after delivery.

Diagnosis is achieved through a 75 g oral glucose tolerance test (2 hour glucose >7.8 mmol/L) or a fasting glucose of 5.6 mmol/L or more. Mothers at risk of gestational diabetes are screened with an oral glucose tolerance test.

Management

• Dietary modification, similar to initial management of T2DM, focusing on balanced meals and controlled carbohydrate intake.
• Dietician input
• Medication - metformin and insulin can be considered if target blood sugar is not achieved.
• Regular fetal monitoring, particularly of growth, to prepare for macrosomia.

Risk Factors

• Maternal BMI over 30
• Family history of diabetes of any sort
• Family history of macrosomia (as these might have been cases of undiagnosed gestational diabetes) 
• Previous baby above 4.5 kg or previous history of gestational diabetes
• Ethnicity with high diabetes prevalence - South Asian, Afro-Caribbean, Middle Eastern

Pre-Eclampsia

Pre-eclampsia is a potentially serious disease in the mother during pregnancy. It is defined as hypertension of 140/90 or more and proteinuria after 20 weeks gestation in a previously normotensive woman.

The cause of pre-eclampsia is caused unclear but is associated with inadequate trophoblastic invasion of the placental arterioles. As a result there is associated fetal growth restriction and placental failure so the body attempts to increase blood flow to the placenta. This is done by raising the maternal blood pressure, which causes kidney damage, resulting in proteinuria.

Symptoms and Signs

• Headache
• Visual disturbances
• Hyperreflexia
• Oedema
• Seizures
• Right upper quadrant pain (liver related pain)

Risk Factors

• Maternal age over 40
• Maternal obesity
• Personal or family history of pre-eclampsia.

Treatment 

• Delivery of the fetus. This is the most effective treatment, because it removes the need for the increased blood pressure.
• Antihypertensives

Edited by: Dr. Ben Appleby

Reviewed by: Dr. Thomas Burnell

Quiz

Preview the Diseases of the Mother in Pregnancy quiz