Is the fetal lung developed and mature at 35 weeks of pregnancy?

Generally, at 35 weeks of gestation, a fetus's lungs are mostly approaching maturity but have not yet fully reached the maturity level of a full-term infant. If the fetus has growth restrictions, preterm birth risks, or lung development-related conditions, lung maturity may be insufficient. In case of concerns, it is recommended to seek medical advice in advance. Detailed analysis is as follows:

If the fetus is developing normally at 35 weeks' gestation with no significant complications, assessments via ultrasound or other relevant tests may show gradually sufficient production of pulmonary surfactant and basic respiratory function. In such cases, the lungs are considered nearly mature. If born at this stage, most infants can breathe normally with medical support, although close monitoring of respiratory status is still required.

If fetal growth restriction is present at 35 weeks, or if the mother has complications such as gestational diabetes or hypertension that affect fetal lung development, or if the fetus itself has structural lung abnormalities, surfactant production may be inadequate, resulting in lower lung maturity compared to normally developing fetuses. In such cases, premature delivery may lead to respiratory distress and require more comprehensive medical intervention.

At 35 weeks’ gestation, regular prenatal checkups should be conducted as prescribed, allowing assessment of fetal lung development. Pregnant women should ensure adequate rest, avoid strenuous activities, and minimize the risk of preterm labor.