Objective: The objective of this study is to determine a healthy fetal growth pattern of twins from a Polish population based on an outcome-dependent growth curve.
Methods: The fetal growth data of live-born twin pregnancies between 25th and 40th week gestation in the period of 1 January 2005 to 31 March 2018 from the database of a tertiary care women's hospital in Western Poland was used to calculate birth weight percentiles. The growth curves of singletons from the same database were used as comparison. Because this study aimed for an outcome-dependent approach for the calculation of fetal growth curves, all babies born that may have high risk of unfavorable outcome were excluded. After application of all exclusion criteria, 1317 records referring to 2634 children were included in our analysis. Growth curves of singletons from the same database were used as reference for this study.
Results: A linear relationship between 10th, 50th, and 90th percentiles and gestational age were found for twins but not for singletons suggesting the different mechanisms of intrauterine growth between singleton and twin pregnancies. Week-to-week weight gain equal to or higher than 150 g in twins also predict a favorable outcome in absence of other pathologies.
Conclusion: The calculated outcome-dependent fetal growth curves for twins in this study may help in the accurate diagnosis of small or large twin fetuses for their gestational age in this Western Poland population.
Keywords: Growth curves; birth weight percentiles; twin pregnancies.