Cranial shapes of Japanese preterm infants at one month of age using a three-dimensional scanner

Abstract

Background: Recently, cranial shape measurements of preterm infants have been performed using handheld three-dimensional (3D) scanners and can now be objectively quantified.

Aims: To measure the cranial shapes of Japanese preterm infants at one month of age using a 3D scanner, compare these values with those of healthy term infants, and examine the risk factors for dolichocephaly.

Study design: A multicenter, retrospective cohort study.

Subjects: Preterm infants born at <37 weeks of gestation and staying in the neonatal intensive care unit or visiting an outpatient clinic for a one-month checkup between April 2020 and March 2022.

Outcome measures: A 3D scanner was used to quantify cranial shape. Comparison was made with full-term, one-month-old infants.

Results: Ninety-four preterm infants (42 boys) and 165 full-term infants were enrolled. Preterm infants had a significantly lower cephalic index (77.9% and 85.0%, p < 0.01) and a higher incidence of dolichocephaly (54.3% and 13.3%, p < 0.01) compared to term infants. No significant difference in incidence of deformational plagiocephaly was found between the groups (41.5% vs. 47.3%, p = 0.44). The risk of dolichocephaly was significantly higher for female sex (odds ratio [OR], 3.32; 95% confidence interval, 1.30-8.50), cesarean section (OR, 4.07; 95% confidence interval, 1.23-13.5), and use of mechanical ventilation (OR, 4.66; 95% confidence interval, 1.09-20.0).

Conclusions: Japanese preterm infants at the first month of life had longer heads than full-term infants; the risk factors identified were female sex, cesarean section, and use of mechanical ventilation.

Keywords: Cephalic index; Cranial shape; Dolichocephaly; Infant; Three-dimensional scanner.