Follow-up examination at the age of 15 months of extremely preterm infantsafter postnatal estradiol and progesterone replacement

A randomized controlled pilot study was performed with a sample of extremel y preterm infants to evaluate the impact of postnatal estradiol and progest erone replacement on postnatal bone mineral accretion. Twenty-five of 30 in fants in the pilot study survived, and of these, 24 infants were available for the follow-up examination at a median chronological age of 18.1 months (minimum-maximum, 17.0-20.6) corresponding to a corrected age of 14.8 month s (minimum-maximum, 12.9-17.4). Somatic growth data and bone mineralization showed no differences between the hormone-treated and control group infant s. The deviation of the skeletal age from the corrected age was 0.0 months (minimum-maximum, -7.7 to 7.4) for hormone-treated infants compared with -1 .7 months (minimum-maximum, -7.5 to 5.9) for the control group. The Bayley scales mental and psychomotor developmental indexes were 89 (minimum-maximu m, 71-107) and 101 (minimum-maximum, 49-121) for the hormone-treated infant s and 93 (minimum-maximum, 49-111) and 71 (minimum-maximum, 49-121) for the control group infants, respectively (mental developmental index, P = 1.0; psychomotor developmental index, P = 0.14). The normal psychomotor developm ent in the hormone-treated infants compared with the below average developm ent in the control group infants is encouraging and indicates the potential ly important integrative role of sex steroids for the developing brain. Lar ger studies on the effects of the postnatal replacement of estradiol and pr ogesterone in extremely preterm infants are warranted.