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

Abstract

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.

Seasonality of Birth Weight in Singleton Full-term Births in Finland

“…This is in line with studies from the United States (Donahue et al, 2010;Morisaki et al, 2013;Oken, 2013) and South Korea (Hur, 2023). However, other countries have found either mixed results (Diouf et al, 2011) or an increase in birth weight across time (Ghosh et al, 2018;Olsen et al, 2023;Schack-Nielsen et al, 2006). A study by Sankilampi and colleagues (2013) shows an increase in mean birth weight in Finland between 1979Finland between -1983Finland between and 1996Finland between -2008 Our study complements this study and we assume that there is a higher mean birth weight between 1987-1996 than both time periods (1979-1983 and 1996-2008) as presented by Sankilampi and colleagues, with a following decline.…”

“…The increase was still present after controlling for the increase in maternal age and decrease in smoking. A recent study from the Faroe Islands showed an increase of 93 grams in birth weight of singleton Faroese infants born between 2010-2019, although the same increase could not be found in other Nordic countries (Olsen et al, 2023). The authors suggest that this could possibly be explained by a larger proportion of infants born in gestational week 41 or later compared to the other Nordic countries, which possibly could relate to differences in the practice of labour induction (42 weeks and 0 days in Faroe Islands and 41weeks and 5 days in other Nordic countries).…”

Birthweight trends and their explanatory factors in Hungary between 1999 and 2018: an analysis of the Hungarian Tauffer registry

“…The increasing birthweight trend observed in the first period (1999-2008) parallels with similar observations from other high income countries [6][7][8][9][10][11][12][13][14]17] including those from Croatia [15], Poland [40] and a regional database analysis from Hungary [33].…”

“…Given the strong association between birthweight and later chronic diseases, even small temporal changes in the distribution of term newborns' birthweights could be of utmost public health importance. Indeed, an upward birthweight trend was observed in several high income countries and regions (such as the United States (US) [6], Canada [6,7], the United Kingdom (UK) [8,9], Norway [10], Sweden [11], Denmark [12], France [13], Australia [14], Croatia [15], Poland [16], and the Faroese Island [17]) at the end of the last century. In contrast, a reverse trend was found in Japan [18,19] and the increase appeared to reverse in the US [20][21][22][23][24][25], China [26,27], Portugal [28], Norway [29,30], and Germany [31] after the 1990s.…”

“…While birthweight changes are well described in the literature, potential explanatory factors are much less known and these factors explain only parts of the slope of the birthweight trajectories. Most studies suggest that the increasing trends are associated with older maternal age [8, 9, 12-14, 19, 33], increasing maternal body mass index (BMI) [11][12][13][14] and height [15,19], longer gestations [10,12,13,17,19], decreases in smoking [11][12][13][14], decreasing parity [13,15,17], changes in ethnicity [9] and socioeconomic factors [9,15], while the decreases could be related to decreases in the length of gestation [18-20, 22, 25, 28], induction of labour [6,20,22,24,25], and early term caesarean sections [6,20,22,24], increases in primiparity [18,19], and decreased foetal growth [22,23].…”