Pulmonary diffusing capacity in pregnancy at sea level and at high altitude

Area of Science:

• Physiology
• Environmental Health
• Obstetrics

Background:

• Optimizing respiratory management for pregnant women, especially those with pulmonary disease, requires understanding pregnancy's impact on lung function.
• Living conditions, specifically altitude, may influence these respiratory adaptations during pregnancy.

Purpose of the Study:

• To determine how pregnancy affects pulmonary diffusing capacity (DL(COc)).
• To investigate whether altitude of residence modifies the impact of pregnancy on DL(COc).

Main Methods:

• Pulmonary diffusing capacity corrected for hemoglobin (DL(COc)) was measured in 112 pregnant and 19 non-pregnant women at sea level.
• DL(COc) was also measured in 192 pregnant and 19 non-pregnant women residing at 4300 m altitude.
• Data were analyzed comparing DL(COc) between pregnant and non-pregnant women at different altitudes and trimesters.

Main Results:

• At sea level, mean DL(COc) was similar between pregnant and non-pregnant women.
• At high altitude, mean DL(COc) was higher in pregnant women compared to sea-level counterparts.
• In high-altitude pregnancies, third-trimester DL(COc) was lower than in non-pregnant women.

Conclusions:

• Pregnancy's effect on pulmonary diffusing capacity is significantly influenced by the altitude of residence.
• High altitude may exacerbate the changes in pulmonary diffusing capacity observed during late pregnancy.