Caffeine, theophylline and theobromine in pregnancy.

Abstract

Dietary surveys estimated the caffeine intake of pregnant women in London to average 1.4 mmol (270 mg) with a range of 0 to 6.0 mmol (0-1160 mg)/day. The average plasma caffeine was 6.5 (SD 2.8-14.8), plasma theophylline 2.9 (SD 1.3-6.7), plasma theobromine 2.1 (SD 0.9-4.9) mumol/l. The results of the dietary surveys showed a fair correlation (r = 0.59; p less than 0.01) with plasma caffeine levels, but the surveys are best regarded as a basis for counseling rather than an accurate estimate of intake.