CaffeineNutrition library
Caffeine
Crosses the placenta freely and is metabolised slowly by the fetus, so pregnancy guidance caps total intake at under 200 mg/day.
Trimester focus
| Stage | For the mother | For the baby |
|---|---|---|
| First trimester | Caffeine clearance slows as pregnancy progresses, raising effective exposure for a given dose. | The fetus cannot metabolise caffeine — even modest maternal intake reaches it fully. |
| Second trimester | The 200 mg/day cap continues to apply. | Continues to be exposed to whatever the mother consumes, unmetabolised. |
| Third trimester | Clearance is at its slowest, so the same dose has the largest effect. | Same full exposure; no fetal metabolism develops during pregnancy. |
Target note
Keep total < 200 mg/day in pregnancy.