Birthweight and gestational age in the Faroe Islands: A comparison between birthweight and gestational age in the Faroe Islands and other Nordic countries.

INTRODUCTION

This study aimed to examine Faroese infants' birthweight and gestational age in 2010-2019 and compare these findings with other Nordic countries. Risk factors for high birthweight among Faroese infants were also investigated in this study.

MATERIAL AND

METHODS

All singleton liveborn infants registered in the Faroese Birth Registry in 2010-2019 were included in the study (n = 6121). A comparison was made with data on birthweight and gestational age from Denmark, Iceland, Norway, and Sweden.

RESULTS

The mean birthweight increased significantly from 3652 g (95% confidence interval [CI]: 3505-3699 g) in 2010 to 3745 g (95% CI: 3700-3790 g) in 2019, a mean increase in birthweight of 93 g (95% CI: 28-158 g) (p < 0.05). The birthweight increased 186 g (95% CI: 179-193 g) for each gestational week and 11 g (95% CI: 7-15 g) for each year. Changes in gestational age explained 31% of the change in birthweight. The proportion of infants weighing 4500 g or more increased significantly from 6.1% in 2010 to 9.6% in 2019 (p < 0.05). The risk of giving birth to an infant weighing 4000 g or more was consistently associated with previously giving birth (OR 1.98 (95% CI: 1.71-2.30)) and gestational age (OR 1.28 (95% CI: 1.23-1.33) per week increase in gestational age). Infants born in gestational weeks 40 and 42 in 2019 had a higher birthweight z-score than infants born in gestational weeks 40 and 42 in 2010. Compared to other Nordic countries, Faroese infants' mean birthweight was high, the Faroe Islands had a higher number of infants born with a weight of 4000 g or more and a higher proportion of infants born in gestational week 41 or later (31.5%).

CONCLUSIONS

Our results showed that the mean birthweight and the proportion of infants with high birthweight significantly increased during 2010-2019 in the Faroe Islands. The mean birthweight, the proportion of infants with high birthweight and the gestational age at birth for Faroese infants was higher than all other Nordic countries. The reasons for this require further investigation.