17 beta-estradiol and progesterone supplementation in extremely low-birth-weight infants

During pregnancy, 17 beta-estradiol (E2) and progesterone (P) plasma concen trations increase up to 100-fold. The fetus is exposed to these increasing amounts of E2 and P. Within 1 d after delivery, E2 and P concentrations fal l to nonpregnancy concentrations in the mother and the infant. Extremely pr emature infants are cut off from the placental supply of E2 and P at a very early developmental stage, and therefore they suffer from this deprivation for a longer period than infants born at term. Nothing is known about the consequences of this deprivation, The purpose of this study was to investig ate how intrauterine concentrations of E2 and P could be maintained after b irth. In 13 infants with a median gestational age of 26.4 wk (24.1-28.7), a phospholipid-stabilized soybean oil emulsion available for parenteral nutr ition that contains different amounts of E2 and P was continuously administ ered, starting within the first postnatal hours. The supplementation was co ntinued as long as venous access was indicated but not longer than 6 wk (me dian 20 d, 12-44). To maintain intrauterine plasma concentrations of 2000-6 000 pg/mL E2 and 300-600 ng/mL P, 2.30 mg.kg(-1).d(-1) E2 (1.13-3.42 mg.kg( -1).d(-1)) and 21.20 mg.kg(-1).d(-1) P (11.23-27.36 mg.kg(-1).d(-1)) were n eeded, We conclude that supplementation of E2 and P to maintain intrauterin e concentrations in extremely premature infants is possible intravenously. The infants in this study are enrolled in a randomized, controlled pilot st udy to evaluate the potential benefits of E2 and P supplementation.