This page details only the elements of asthma management pertinent to pregnancy; see the asthma page from the ICM section for a more thorough overview.
Reduced cortisol sensitivity (as progesterone binds the receptor)
Reluctance to take usual medications
Up to 10% of women will require hospital admission for an acute exacerbation during pregnancy
Asthmatic parturients are more likely to have complications such as pre-term delivery, low birth weight and pre-eclampsia
Ante-natal
Respiratory referral
Continuation of all regular treatment; no evidence of foetal harm from any asthma medications
Regular home assessment of peak flow to detect deteriorations early
Relative contraindication to use of β-blockers in management of pre-eclampsia
Intra-partum
Continue all regular medications, despite the possible uterine effects of β-agonists
May require steroid cover
Epidural analgesia is beneficial to avoid pain-associated hyperventilation, which can precipitate acute attacks in some patients
Prostaglandin analogues are contraindicated in the management of uterine atony
Regional anaesthesia is preferable to GA, as with virtually every parturient
Acute attacks
Acute attacks may cause maternal hypoxia and hypocapnoea
This reduces foetal oxygen delivery via vasoconstriction of the umbilical artery and left-shift of the oxyHb-dissociation curve
Management is the same as for non-pregnanct patients
One difference is a patient should be deemed to be 'tiring' at a PaCO2 of 4.0kPa, rather than a normal PaCO2, owing to the lower levels during pregnancy