Our results showed that after controlling for the child’s age, sex, and maternal educational levels, the risk of poor handwriting for late preterm born children was approximately fourfold as high as their full-term peers in the second grade. To our knowledge, this was the first study to investigate the handwriting performance of children born late preterm. The present findings on handwriting performance of late preterm born children were consistent with the previous findings, which indicated that this population were still at a higher risk for poor developmental outcomes than children born at term even though their gestational weeks were near term [4, 5]. However, our findings were slightly different from Feder et al.’s findings on handwriting performance of children born below 34 weeks of gestation, who demonstrated both problems of poor legibility and slow speed . Our late preterm participants had handwriting difficulty particularly in the dimension of Chinese character construction, one component of legibility. This inconsistency may be attributed to the difference of gestational weeks at birth. As expected, earlier preterm births generally lead to greater adverse impacts on brain development  and developmental outcomes .
Our results demonstrated that even in the absence of history related to developmental delays after birth, close to 20% of late preterm children performed the worst in handwriting. This finding implies some mild deficits in late preterm children may be not discovered until they are required to complete complicated tasks (e.g., handwriting) when they are older. Future studies are required to further investigate the relationship between early medical factors and poor handwriting to define the high-risk subgroup born late preterm. A long-term, comprehensive developmental follow-up program may be provided to them to prevent later difficulties in school function.
As mentioned before, the late preterm children particularly had difficulty with spatial construction of Chinese characters and components, including spacing, size, alignment, and slant, which may lead to handwriting illegibility. Previous studies have demonstrated that visual perception , tactile and kinesthetic perceptions , visuomotor integration [22, 23], in-hand manipulation (i.e., translation and rotation of a small peg within one hand), and motor coordination (i.e., tracing the forms by connecting dots within provided paths)  are significant factors related to handwriting legibility. Future research can examine the relationships among these potentially underlying factors and the poor character construction in late preterm children to provide a guide for supportive intervention for their handwriting problems.
Regarding developmental outcomes of children born early term, previous studies have indicated that they have a slightly increased risk of developmental (e.g., language and cognitive problems) and school functional problems (e.g., lower academic achievement) than their peers born at full term [5, 7, 8]. However, we did not find such a difference between early term and full term children in terms of their handwriting performance. The absence of a significant difference between these two gestational age groups in our study may partially be a result of a higher ratio of 38 weeks to 37 weeks gestation in our early term group (4.6:1). The ratio of 38 weeks to 37 weeks gestation shown in the population cohorts is approximately 3:1 in the literature [9, 24]. Recent studies have reported that compared to children born at full term, a significantly poorer cognitive development  and school achievement (grammar and numeracy)  is mainly found in those born at 37 weeks but not at 38 weeks of gestation. Whether there is a similar difference in handwriting between children born 37 and 38 weeks of gestation requires further investigation with larger sample.
Our results demonstrated an independent contribution of some demographic factors to poor handwriting in grade two, including being younger, being male, and having mothers with below collage/university education. The later-born effect on school performance was consistently found in other studies, which revealed the associations between older age at the entrance of elementary school and lower risk of poor handwriting  and higher academic achievements in the first grade . In addition, consistent with Feder et al.’s findings on English legibility , we also found that boys had a greater risk of having difficulties in Chinese handwriting legibility as compared to girls. Furthermore, there was a significant association between maternal education levels and the risk of poor performance in the accuracy dimension. These results suggest that these demographic risk factors are important to be considered in investigating the handwriting performance of students in the lower elementary school grades.
There were a few limitations in the present study, such as a small convenience sample and subjective ratings of class teachers on the children’s handwriting performance. A larger sample size and direct handwriting assessment tools would be needed to confirm our findings. In addition, future studies examining the handwriting performance of late preterm children using different languages are also necessary.