Ultra Low Birth Weight Infants (ULBWI, Birth Weight < 500 g), a New Challenge

Recently, as the survival rate of ELBW infants with a birth weight of less than 1000 g has rapidly increased worldwide, interest in some of them, infants with a birth weight of less than 500 g, is increasing. According to some reports, the survival rate of infants weighing less than 500 g is also known to increase over time. However, various information is still lacking. These tiny infants present new challenges for neonatologists caring for premature babies. As this new group of infants has not been officially named by the World Health Organization, we would like to refer to them as ultra low birth weight (ULBW) infants through this topic.

An epidemiological study on the survival rate and long-term prognosis of ULBW infants was recently published. However, epidemiological data are still insufficient, except for some reported countries and regions. Depending on the country, region, and institution, ULBW infants have different survival rates and morbidity rates.

The primary goal of this Research Topic is to establish that infants weighing less than 500 g are distinctly different in terms of survival, morbidity, and long-term prognosis from VLBW and ELBW infants. For example, there would be differences in the process of treatment. We also wish to address the ethical aspects in relation to caring for ULBW infants and the importance of parental counseling.

We welcome manuscripts on the following themes:
• Epidemiological statistics that have not yet been reported by country or region for ULBW infants (compared to ELBW infants)
• Factors related to survival in ULBW infants
• Factors associated with morbidities in ULBW infants
• Ethical issues in the treatment of ULBW infants
• Counseling for parents of ULBW infants