Original Article Characterizing Early State Regulation in Preterm Infants Jonathan S. Litt, MD, MPH, ScD,* Timmy Ho, MD, MPH,* Evelyn Obregon, MD,* Palak Patel, BA,* Tiglath Ziyeh, BA,* Marie C. McCormick, MD, ScD*† ABSTRACT: Objectives: To characterize state regulation and behavior of preterm infants after discharge from the neonatal intensive care unit (NICU). Methods: We recruited singleton infants born at £35 weeks of gestational age (GA) before NICU discharge. Parents completed surveys at discharge and 1, 3, and 6 months after discharge. Infant medical history was gleaned from the medical record. Surveys captured sociodemo- graphic information and measures of infant state regulation (Baby Pediatric Symptom Checklist [BPSC]) and feeding behaviors. We calculated the median BPSC subscale scores at each time point and the proportion of infants with scores in the problem range (‡3/5). We explored longitudinal and cross-sectional correlates of BPSC scores. Results: Fifty families completed the discharge questionnaire, and 42 (84%) completed the 6- month questionnaire. The median GA at birth was 34 weeks (IQR 30.1, 34.4 weeks); the median birth weight was 1930 g (IQR 1460, 2255 g). The median scores were above population norms for irritability and difficulty with routines. Twenty-one infants (40%) had irritability subscale scores in the problem range at 1 month, and 20 (38%) had problem scores on difficulties with routines. Only 9 infants (17%) had problem scores on the inflexibility subscale. Scores in all 3 domains showed different patterns from population norms from 1 to 6 months. BPSC scores were correlated with infant feeding behaviors at 1, 3, and 6 months. Conclusion: Scores for irritability and difficulty with routines among preterm infants were high compared with population norms and differed from normative values through 6 months after discharge. Preterm infants demonstrate problems with state regulation after NICU discharge that may require directed intervention. (J Dev Behav Pediatr 40:293–300, 2019) Index terms: preterm infant, state regulation, infant behavior. State regulation is defined as a newborn’s ability to manage their level of arousal. 1 In response to internal or external stimuli, infants may transition between 1 of 6 behavioral states: quiet sleep, active sleep, drowsy, alert, fussy, and crying. Moving from 1 state to another requires the ability to organize one’s own behavior. 1 This may be manifested outwardly by an infant’s tempera- ment, with the so-called easy babies making smooth transitions and difficult babies exhibiting more abrupt shifts between states. 1,2 It is believed that infant state regulation is the precursor to self-regulation, a related concept concerning a child’s ability to regulate their emotions appropriately to a given situation and pur- posefully attend to people and objects in their environ- ment. 3 This important process underlies social relatedness, attention, and cognition. 4 It has been postulated that state regulation has its origins in fetal life. DiPietro and colleagues studied 52 typically developing fetuses in the third trimester and found that fetuses displayed concordance between heart rate and activity by 36 weeks of gestation, a pattern be- lieved to reflect behavioral organization. They also showed that infants with higher levels of fetal behavioral organization had higher scores on tests of state regula- tion at 41 weeks of postmenstrual age. 5 Patterns of sleep and waking behaviors have been shown to be stable from infancy through toddlerhood among healthy, term- born children. 6 A small case-control study of children with behavior problems at school age found difficulties with state regulation at 9 months to be significant pre- dictors of high problem scores on the Child Behavior Checklist. 7 Another group conducted a prospective co- hort study to explore the relationship between newborn behavior patterns and affect and temperament in later childhood. The study revealed a significant association between state regulation at 3 days of life and negative affect at age 12 months and a significant but negative association between state regulation at 30 days of life and general activity level at age 6 years. 8 Studies of several distinct populations of infants have revealed altered capacity for state regulation. Compared with infants born with appropriate size for gestational age (GA), those born with small size for GA have shown difficulty with state regulation that normalizes by the end of the first month of life. 9 Amini et al. 10 describe a high level of correlation between state regulation behaviors and motor performance in a small cohort of infants born with birth weight ,2500 g. A Japanese group has found that difficulty with state regulation among infants with From the *Department of Neonatology, Beth Israel Deaconess Medical Center, Boston, MA; †Department of Social and Behavioral Sciences, Harvard TH Chan School of Public Health, Boston, MA. Received May 2018; accepted December 2018. Disclosure: The authors declare no conflict of interest. Address for reprints: Jonathan S. Litt, MD, MPH, ScD, Department of Neo- natology, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Rose 3, Boston, MA 02215; e-mail: jlitt@bidmc.harvard.edu. Copyright Ó 2019 Wolters Kluwer Health, Inc. All rights reserved. Vol. 40, No. 4, May 2019 www.jdbp.org | 293 Copyright © 2019 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.