Research, Society and Development, v. 11, n. 6, e58311629468, 2022 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v11i6.29468 1 Extreme prematurity in a public reference unit: morbidity, viability and mortality Prematuridade extrema em uma unidade pública de referência: morbidade, viabilidade e mortalidade Prematuridad extrema en una unidad pública de referencia: morbilidad, viabilidad y mortalidad Received: 04/21/2022 | Reviewed: 04/29/2022 | Accept: 05/07/2022 | Published: 05/12/2022 Patricia Fabiane Monteiro Laranjeira ORCID: https://orcid.org/0000-0001-9604-0573 Centro Universitário Cesmac, Brazil E-mail: pfmlaranjeira@hotmail.com Vanessa de Carla Batista dos Santos ORCID: https://orcid.org/0000-0002-3990-327X Centro Universitário Cesmac, Brazil E-mail: nessadecarlla@yahoo.com.br Janaína da Silva Nogueira ORCID: https://orcid.org/0000-0001-5125-982X Centro Universitário Cesmac, Brazil E-mail: jana-nog@hotmail.com Ana Clara Monteiro Laranjeira ORCID: https://orcid.org/0000-0001-5306-3804 Universidade Estadual de Ciências da Saúde de Alagoas, Brazil E-mail: clarinha_ana_@hotmail.com Gabriel Monteiro Amorim ORCID: https://orcid.org/0000-0002-8282-4526 Universidade Federal de Alagoas, Brazil E-mail: gabriel.amorim@famed.ufal.br Rafael Monteiro Laranjeira ORCID: https://orcid.org/0000-0002-7609-6868 Universidade Federal de Alagoas, Brazil E-mail: rafael.gpcr@hotmail.com Kevan Guilherme Nóbrega Barbosa ORCID: https://orcid.org/0000-0002-9410-7356 Centro Universitário Cesmac, Brazil E-mail: kevanguilherme@gmail.com Abstract Premature birth is a public health problem due to the high mortality rate associated and risk of severe disabilities throughout life. The objective was to evaluate the morbidity and mortality in a high-risk maternity hospital and knowing the threshold of viability. The sample was selected in four stages: identification, selection, stratification of preterm infants by gestational age and birth weight, and structured data collection. Neonates up to 31 weeks of gestational age who had a death outcome were evaluated from August 2015 to August 2020 through a retrospective survey based on the descriptive analysis of variables related to pregnancy, childbirth, and the newborn. Absolute and relative percentages were described for the categorical variables and calculated mean, median and standard deviation, minimum and maximum value for continuous quantitative variables. Most newborns had a small gestational age (56.3%), extremely low birth weight (39.8%), and presented with asphyxia (38.7%). The main morbidities were respiratory distress syndrome (100%) and sepsis (40.6%). The overall mortality rate was 55.9% from 26% at 31 weeks to 100% at 22 weeks; most deaths (56.3%) occurred between 22 and 27 weeks. Of the 266 deaths, 25 (9.3%) still occurred in the delivery room and 237 (89%) in the neonatal unit. The early mortality rate was 0.77 deaths per 1,000 live births, and the late mortality rate was 0.22 deaths per 1,000 live births. Viability’s limit found was 28 weeks. Death, in addition to fetal characteristics, was influenced by a series of modifiable risk factors. Keywords: Premature; Morbidity; Mortality; Fetal viability. Resumo O nascimento prematuro é um problema de saúde pública, pela elevada mortalidade e pelo risco de deficiências graves ao longo da vida. O objetivo foi avaliar a morbidade e a mortalidade numa maternidade de alto risco e conhecer o limiar de viabilidade. A amostra foi selecionada em quatro estágios: identificação, seleção, estratificação dos prematuros por idade gestacional e peso de nascimento e preenchimento de formulário estruturado. Foram avaliados neonatos até 31 semanas que tiveram desfecho óbito, no período de agosto de 2015 a agosto de 2020, através de levantamento retrospectivo, baseado na análise descritiva de variáveis relacionadas à gestação, ao parto e