Since the 1960s, pediatrics has relied on growth statistics derived by Dr. Lula Lubchenco, known familiarly as the “Lula Gram” or the “Lubchenco Curves.”  But Irene Olsen, Adjunct Assistant Professor in the School of Nursing, whose specialty is the growth assessment of premature infants, decided there needed to be a more up-to-date method of determining where especially premature infants should be in terms of growth.

“You measure and weigh these infants each day and measure their intakes and outputs.  What they receive for nutrition is primarily through tubes,” said Olsen.  Thus, she said, knowing what is “normal” size for a premature baby at each age is vital to knowing how to guide its nutrition and support healthy growth and development.

Olsen’s research has expanded far beyond the 5,000 nearly all-white babies Lubchenco measured in Denver at mid-Century to records of more than 400,000 babies from 1998-2006 that reflect the diversity of American children.  If taken as the standard, they may well become the “Olsen Curves.”

What Olsen has found is that overall the younger premature babies today are smaller and the older term or near-term babies tend to be bigger than in the past.  She has theorized that in part since more sick premature babies survive these days, their birth weights tend to be smaller, but that since mothers now are bigger and gain more weight during pregnancy, those babies who go to term may tend to be larger.  Further, she said, that the Lubchenco study was done solely in Denver, the effect of that city’s high altitude may have shown in the data – although this point remains controversial in the literature.

Olsen said the new set of growth curves created and validated in her study will make it easier for those in neonatology to assess the growth and nutritional needs of, most vitally, premature infants and that nurses, who are on the front lines in this regard, will be more equipped to handle even the most delicate cases.