Asthma is a chronic inflammatory disorder of the airways characterized by recurrent episodes of wheezing, breathlessness, chest tightness, and coughing, particularly at night or in the early morning. In the context of Nigerian midwifery practice, caring for pregnant women with asthma requires a solid understanding of how respiratory physiology changes during pregnancy. The growing uterus elevates the diaphragm, which reduces functional residual capacity and increases oxygen consumption. This physiological adaptation means pregnant women have a lower physiological reserve to cope with bronchoconstriction. Midwives must identify pre-existing respiratory conditions during the first antenatal visit so that a proactive management plan can be established before complications arise.
The underlying mechanism of asthma involves three major processes: airway inflammation, bronchospasm, and mucus hypersecretion. When a susceptible person encounters a trigger, mast cells in the airways release inflammatory chemicals that cause the surrounding smooth muscles to constrict. At the same time, the airway lining swells and produces thick mucus, severely narrowing the airway lumen. Common triggers in the Nigerian environment include dust mites, harmattan dust, indoor smoke from biomass fuels used in cooking, pollen, viral respiratory infections, and emotional stress. Identifying and avoiding these specific triggers is a cornerstone of preventing acute attacks.
During an asthma evaluation, midwives look for classic signs and symptoms that point toward airway obstruction. Patients typically report shortness of breath, a dry or productive cough, and a tight feeling in the chest. On auscultation, widespread expiratory wheezing is the hallmark physical finding, though silent chest regions indicate severe, life-threatening air trapping. In moderate to severe cases, accessory muscle use in the neck and chest, tachypnea, and an inability to speak in full sentences become apparent. Monitoring peak expiratory flow rate provides an objective measurement of how well air moves out of the lungs.
Uncontrolled maternal asthma poses serious risks to both the mother and the developing fetus. When maternal oxygen levels drop due to bronchospasm, uteroplacental blood flow decreases, leading to chronic fetal hypoxia. This oxygen deprivation can result in intrauterine growth restriction, low birth weight, preterm birth, and increased perinatal mortality. Conversely, well-controlled asthma generally carries a perinatal outcome similar to that of non-asthmatic pregnancies. Midwives play a vital role in reassuring mothers that keeping their asthma under control with safe medications is far safer for the baby than suffering repeated hypoxic episodes from untreated attacks.
Managing asthma during pregnancy requires a careful balance between controlling symptoms and ensuring fetal safety. Treatment relies on a stepwise approach using two main categories of drugs: controllers and relievers.
An acute asthma exacerbation is a medical emergency that demands swift, calm action from the midwifery and nursing team.
Empowering women with asthma to manage their condition independently reduces emergency hospital visits and improves pregnancy outcomes. Midwives must educate patients on how to correctly use metered-dose inhalers with spacer devices, explaining that medication must reach the small airways rather than coating the back of the throat. Women should learn to recognize their personal early warning signs of worsening asthma, such as a drop in peak flow readings or increased nighttime coughing. Providing a written action plan helps patients know exactly when to increase controller medications and when to seek immediate medical help at the health facility.