Mrs. Henry was appointed Midwife-in-Chief at the Port Royal Maternity (Paris, France) in 1881 with the mission to experiment and develop the care of premature infants in incubators. Six incubators were set in use, attended by 5 wet nurses. Due to its success, the service was soon overloaded. Mrs. Henry raised money through the “oeuvre des couveuses”. With the help of public and private funding, the pavilion for nurslings was opened in 1893 and accommodated 14 incubators. Mrs. Henry directed this service for 18 months until 1895. She gave her resignation when Dr. Budin succeeded Dr. Tarnier. During this period, 721 infants were treated (90% of infants were breastfed); 664 were discharged in good condition and 357 died. In this group 24 were not viable, 15 had grave malformations, 68 were moribond on arrival. The smallest infant was 780 gm at 5.5 months gestation. He survived 113 days and died of a cyanotic spell. Among 74 infants fed artificially, 41% died of enteritis. Various experiments were conducted using diluted sterilized cow's milk, prepared in “an American cooker”, recording intake and outputs. Breast milk produced the best results. Mrs. Henry indicates that artificial feeding was particularly dangerous during the two months following birth. She worked closely with the hospital pharmacist and gave an accurate composition of the artificial formulas.

Among the complications observed were infection of the nasal fossa(vomiting through the nose could not be cleaned easily), bronchopneumonia (15 cases) and ophtalmia (45 cases). Apneic spells and their treatment are very well described. Abdominal distension and milk aspiration was a recognized cause of apneic spells. The reasons for the resignation of Mrs. Henry are not clear, but Dr. Budin found the service poorly kept and facilitated her resignation.

We consider that Mrs. Henry was the first director of a special care unit for sick newborns. When Dr. Budin became the Obstetrician-in-Chief, he introduced more scientific rigor and methodology in the treatment of the weaklings. Prospective data were recorded and reproduced in the first neonatology book: The Nursling, published in 1900 with English translation in 1907.