At what gestation should a woman quit smoking for optimal neonatal health outcomes?

Quitting smoking during pregnancy is crucial for optimizing neonatal health outcomes, and the most significant benefits are observed when a woman can stop as early in her gestation as possible. While evidence suggests that quitting smoking at any stage during pregnancy reduces risks associated with low birth weight, preterm birth, and other complications, the body of research points to a key timeframe for maximizing these benefits.

By around 15 weeks of gestation, significant fetal development is occurring, and the placenta is becoming increasingly important in nutrient and oxygen transfer. Quitting at this stage allows for decreased exposure to harmful substances that can disrupt this process, positively influencing fetal development. The earlier a woman quits, particularly before the mid-point of the second trimester, the greater the likelihood of reducing risks associated with smoking during pregnancy.

Later gestational weeks, while still beneficial to quit, may not yield as dramatic improvements in outcomes as seen when cessation occurs earlier. While smoking should ideally be stopped as soon as a pregnancy is confirmed for maximum benefits, the 15-week mark represents a critical juncture where quitting can lead to substantial improvements in neonatal health.