Dexamethasone (Antenatal / OHSS / CAH)

How it works

Dexamethasone is a potent long-acting glucocorticoid that, given antenatally, accelerates fetal surfactant production and lung maturation; it crosses the placenta readily, unlike some other steroids.

Prescribing in practice

• Antenatal corticosteroids should be given for anticipated preterm birth within the recognised gestational window to reduce neonatal respiratory distress, intraventricular haemorrhage and mortality.
• Prenatal dexamethasone for suspected congenital adrenal hyperplasia is experimental and should only be undertaken within specialist services and ideally a research framework.
• Monitor maternal blood glucose, as antenatal steroids can cause hyperglycaemia, particularly in diabetes.

Monitoring

Monitor maternal blood glucose after administration and, where relevant, fetal wellbeing, and limit repeated antenatal courses to defined indications.

Counselling the patient

• Antenatal steroids help your baby's lungs mature before an early birth.
• You may need closer blood sugar monitoring for a few days.
• Prenatal use for adrenal conditions is specialist and individualised.

Evidence & guidelines

Antenatal corticosteroids for fetal lung maturation are supported by long-standing trial evidence and recommended by RCOG and NICE for anticipated preterm birth.