Summary of Infants Weighing 500 Grams or Less

Microcephaly At Birth As a Potential Predictor of Poor Prognosis in Infants Weighing 500 Grams or Less: a Retrospective Cohort Study

This is a retrospective single-center cohort study. The comparison in short- and long-term outcomes will be made between those with and without primary microcephaly in infants weighing ≤ 500 g.

Study Overview

• Status: Completed
• Conditions: Microcephaly; Infant, Extremely Low Birth Weight
• Intervention / Treatment: Diagnostic test: Microcephaly

Detailed Description

This is a retrospective single-center cohort study. The study setting is a level IV neonatal intensive care unit (NICU) at Nagano Children's Hospital in Nagano, Japan. We will retrospectively collect the data of those who were admitted to Nagano Children's Hospital NICU between January 1, 2015, and December 31, 2019. Eligible infants will be identified using our neonatal database and clinical records. The extracted data includes maternal background information and clinical course, infant's status at birth, the clinical course in NICU, and the follow-up data at 6 and 18 months of corrected age.

Among the eligible infants, those with a z score of birth head circumference < -2 will be classified into the Microcephaly group and others into the Control group. The z score is calculated using the Japanese growth standard.

• Study Type: Observational
• Enrollment (Actual): 22

Contacts and Locations

Study Locations

• Japan
  • Nagano
    • Azumino, Nagano, Japan, 399-8288
      • Nagano Children's Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Those who were admitted to Nagano Children's Hospital NICU between January 1, 2010, and December 31, 2019.

Description

Inclusion Criteria:

• Live-born infants weighing ≤ 500 g at birth
• Infants whose clinical course is available in the electronic medical record

Exclusion Criteria:

• Stillbirths
• Infants who received only palliative care at birth
• Outborn infants
• Infants whose assessment at 3 years of age not completed at data analysis

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Microcephaly; Infants with primary microcephaly.	Diagnostic test: Microcephaly; Those with a z score of birth head circumference < -2 (primary microcephaly) are classified into the Microcephaly group.
Control; Infants without primary microcephaly.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Rate of neurodevelopmental impairment	Having at least one of the following conditions: cognitive impairment, cerebral palsy, visual impairment, or hearing impairment. Cognitive impairment was defined as a modified DQ score of ≤ 70 using the Kyoto Scale of Psychological Development. CP was defined as (1) a non-progressive disorder of the central nervous system appearing in the early years of life and clinically characterized by a persistent but not unchanging impairment of movement and posture and/or (2) the Gross Motor Function Classification System level ≥ II. Visual impairment was defined as unilateral or bilateral blindness, or any other condition requiring corrective lenses, which were diagnosed or determined by ophthalmologists. Hearing impairment was defined as unilateral or bilateral hearing loss that requires a hearing aid. The diagnosis of hearing loss was made by otolaryngologists using auditory steady-state response.	3 years of age

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Survival rate	Survival rate is the proportion of those have survived.	At discharge from neonatal intensive care unit, an average at 40 weeks' postmenstrual age.
Rate of severe bronchopulmonary dysplasia	The definition of bronchopulmonary dysplasia proposed by the National Institute of Child Health and Human Development is used to classify the severity of bronchopulmonary dysplasia. Those who need ≥ 30% of oxygen or any mechanical respiratory support at 36 weeks of gestation are classified as having severe bronchopulmonary dysplasia.	At 36 weeks' postmenstrual age
Rate of need for surgery for patent ductus arteriosus	Patent ductus arteriosus is diagnosed by neonatologists using echocardiography and clinical signs.	In neonatal intensive care unit, an average of up to 4 weeks of life
Rate of severe intraventricular hemorrhage	Intraventricular hemorrhage is diagnosed by neonatologists using head ultrasound. Severe IVH was defined as grade III or IV by the classification of Papile.	In neonatal intensive care unit, an average of up to 2 weeks of life
Rate of periventricular leukomalacia	Periventricular leukomalacia is diagnosed using head ultrasound or magnetic resonance imaging, typically cysts formation in the periventricular white matter.	In neonatal intensive care unit, an average of up to 40 weeks' postmenstrual age
Rate of necrotizing enterocolitis	The diagnosis with necrotizing enterocolitis.	In neonatal intensive care unit, an average of up to 2 weeks of life
Rate of sepsis	Sepsis is defined as septicemia or bacteremia with a positive culture result of the blood and/or cerebrospinal fluid.	In neonatal intensive care unit, an average of up to 4 weeks of life
Rate of need for treatment for retinopathy of prematurity	The diagnosis of retinopathy of prematurity and the decision on the need for treatment were made by ophthalmologic examination.	In neonatal intensive care unit, an average of up to 40 weeks' postmenstrual age
Weight	Physical measurement.	At 40 weeks' postmenstrual age or at discharge (approximately 40 weeks' postmenstrual age)
Length	Physical measurement.	At 40 weeks' postmenstrual age or at discharge (approximately 40 weeks' postmenstrual age)
Head circumference	Physical measurement.	At 40 weeks' postmenstrual age or at discharge (approximately 40 weeks' postmenstrual age)
Postmenstrual age	Postmenstrual age is calculated based on their gestational age and date at birth.	At discharge, an average at 40 weeks' postmenstrual age
Need for home oxygen therapy	Need for home oxygen therapy.	At discharge, an average at 40 weeks' postmenstrual age
Tracheostomy	Need for tracheostomy.	In neonatal intensive care unit, an average at 40 weeks' postmenstrual age
Length of hospital stay	The initial hospitalization.	In neonatal intensive care unit, an average at 40 weeks' postmenstrual age
Survival rate	Survival rate is the proportion of those have survived.	At 3 years of age
Modified developmental quotient	Modified developmental quotient is calculated by dividing developmental age (measured by the Kyoto Scale of Psychological Development) by the corrected age.	At 3 years of age
Rate of cerebral palsy	Cerebral palsy is defined as (1) a non-progressive disorder of the central nervous system appearing in early years of life and clinically characterized by a persistent but not unchanging impairment of movement and posture and/or (2) the Gross Motor Function Classification System level ≥ II.	At 3 years of age
Rate of visual impairment	Visual impairment is defined as unilateral or bilateral blindness, or any other condition requiring corrective lenses, which were diagnosed or determined by ophthalmologists.	At 3 years of age
Rate of hearing impairment	Hearing impairment is defined as unilateral or bilateral hearing loss that requires a hearing aid. The diagnosis of hearing loss was made by otolaryngologists using auditory steady-state response.	At 3 years of age
Rate of those who need home oxygen therapy	Need for home oxygen therapy.	At 3 years of age
Rate of those who need tracheostomy	Need for tracheostomy.	At 3 years of age
Rate of those who need tube feeding or gastrostomy	Need for tube feeding or gastrostomy.	At 3 years of age
Rate of those who need rehospitalization	Need for rehospitalization.	After 18 months of corrected age unit until 3 years of age
Weight	Physical measurement.	At 3 years of age
Height	Physical measurement.	At 3 years of age
Head circumference	Physical measurement.	At 3 years of age

Collaborators and Investigators

• Sponsor: Nagano Children's Hospital
• Investigators: Principal Investigator: Ryo Itoshima, MD, Nagano Children's Hospital

Study record dates

Study Major Dates

• Study Start (Actual): April 5, 2022
• Primary Completion (Actual): December 31, 2022
• Study Completion (Actual): December 31, 2022

Study Registration Dates

• First Submitted: March 4, 2022
• First Submitted That Met QC Criteria: April 4, 2022
• First Posted (Actual): April 12, 2022

Study Record Updates

• Last Update Posted (Estimated): November 20, 2024
• Last Update Submitted That Met QC Criteria: November 18, 2024
• Last Verified: November 1, 2024

More Information

Terms related to this study

• Keywords: prognosis; 500 grams or less
• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Nervous System Diseases; Body Weight; Craniofacial Abnormalities; Musculoskeletal Abnormalities; Congenital Abnormalities; Malformations of Cortical Development, Group I; Malformations of Cortical Development; Nervous System Malformations; Birth Weight; Microcephaly
• Other Study ID Numbers: summary-500g

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No