Abstract :
Keywords Monochorionic twins; Selective fetal growth restriction; Attachment; Behavior; Psychosocial development; School functioning Highlights * Birth weight discordant monochorionic twins present with high attachment insecurity. * Smaller twins have a tendency towards negative emotions and behaviors. * Smaller twins attend a lower secondary school level than larger co-twins. * We recommend parent-child guidance throughout pregnancy and the first year. Abstract Background Psychosocial development in monochorionic (MC) twins born after selective fetal growth restriction (sFGR) has been unreported to date, despite its importance for daily functioning and future relationships. Aims To investigate psychosocial development, attachment and school functioning in MC twins with sFGR and compare outcomes with the general population and between smaller and larger twins. Study design Observational cohort study. Subjects MC twins with sFGR (defined as a birth weight discordance [greater than or equal to]20 %) born between 2002 and 2017 and aged 3--17 years. Outcome measures Multiple parent report questionnaires: the Child Behavior Checklist (social-emotional development and behavior), the (Early) Childhood Behavior Questionnaire Very Short Form (temperament), the Attachment Insecurity Screening Inventory (attachment) and a school functioning questionnaire. Results Median age for the 48 twin pairs was 11 (interquartile range (IQR) 8--13) years. Attachment insecurity for both twins was higher than in the general population for ambivalence/resistance (34 % (21/62) vs. 16 %, p = 0.024) and total attachment insecurity (35 % (22/62) vs. 16 %, p = 0.016). Smaller twins had more internalizing behavioral problems, i.e. negative emotions and behaviors turned inwards (22 % (10/46) vs. 11 % (5/46), p = 0.021) and a higher negative affect, i.e. more likely to experience negative emotions (3.2 (2.9--3.7) vs. 2.9 (2.2--3.2), p = 0.009) than larger twins, as well as a lower secondary school level (p = 0.031). Conclusion MC twins with sFGR have more ambivalent/resistant attachment insecurity following the complicated pregnancy course. Smaller twins have a tendency towards negative emotions and internalizing behaviors compared to larger twins, indicating an increased sensitivity for depression and anxiety. Abbreviations MC, monochorionic; sFGR, selective fetal growth restriction Author Affiliation: (a) Neonatology, Willem-Alexander Children's Hospital, Dept. of Pediatrics, Leiden University Medical Center, Leiden, the Netherlands (b) Molecular Epidemiology, Dept. of Biomedical Data Sciences, Leiden University Medical Center, Leiden, the Netherlands (c) Dept. of Medical Psychology, Leiden University Medical Center, Leiden, the Netherlands (d) Fetal Therapy, Dept. of Obstetrics, Leiden University Medical Center, Leiden, the Netherlands (e) Pediatric Cardiology, Willem-Alexander Children's Hospital, Dept. of Pediatrics, Leiden University Medical Center, Leiden, the Netherlands * Corresponding author at: Department of Pediatrics, Leiden University Medical Center, J6-S, Albinusdreef 2, 2333 ZA Leiden, the Netherlands. Article History: Received 17 August 2022; Revised 20 September 2022; Accepted 20 September 2022 Byline: Sophie G. Groene [S.G.Groene@lumc.nl] (a,b,*), Lisette Jansen (c), Ratna N.G.B. Tan (a), Sylke J. Steggerda (a), Monique C. Haak (d), Arno A.W. Roest (e), Enrico Lopriore (a), Jeanine M.M. van Klink (a)