Gestational age at term delivery and children's neurocognitive development

Area of Science:

• Neuroscience
• Developmental Pediatrics
• Public Health

Background:

• Preterm birth is known to impact neurocognitive performance.
• The neurodevelopmental benefits of extending gestation within the full-term range (37-41 weeks) remain unclear.
• Understanding these differences is crucial given high rates of obstetric intervention in the USA.

Purpose of the Study:

• To investigate the association between gestational age at term (37-41 weeks) and neurocognitive development.
• To determine if neurodevelopmental outcomes improve with each additional week of gestation within the full-term range.

Main Methods:

• Secondary analysis of 39,199 singleton births from the US Collaborative Perinatal Project (1959-1976).
• Neurodevelopmental assessments at 8 months (Bayley Scales), 4 years (Stanford-Binet IQ), and 7 years (WISC, WRAT).
• Evaluated outcomes across each week of term gestation (37-41 weeks).

Main Results:

• Neurocognitive performance improved progressively with each week of gestation from 37 to 40-41 weeks.
• Children born at 37 and 38 weeks showed lower scores across most assessments compared to those born at 40 weeks.
• Birth at 39 weeks was associated with lower Bayley Mental and Psychomotor scores, and in sibling analyses, lower Wide-Range Achievement Test scores.

Conclusions:

• Each week of gestation up to 40-41 weeks is vital for optimal short- and long-term cognitive development.
• The 40-41 week gestational window appears to be ideal for maximizing neurodevelopmental outcomes.
• Findings support optimizing delivery timing for improved child neurodevelopment.