The physical development of the quintuplets in their first year of age is described, including anthropological measurements, psychological, hematological, immunological, and other examinations.

Piotr appeared to show the highest rate of height and weight growth; Ewa, the lowest one. In the 7th month of age, head and chest circumference values achieved the standards of singletons born at term. Psychomotor development of the quintuplets was not only proper but even exceeding. Teething occurred in the 8th-10th month. Hematological examinations in the first 6 months showed some anemia, which disappeared in the 7th month. Other laboratory examinations did not show any deviations, except for slightly lowered serum level of gamma-globulins. In their first year of age the children suffered from nearly any diseases. The infections of the upper respiratory tract showed a mild course.