IN HEALTHY FULL AND LATE PRE-TERM BABIES, DOES DELAYING THE FIRST BATH UNTIL AT LEAST 24 HOURS OF LIFE EFFECT IN-HOSPITAL BREASTFEEDING RATES, THERMOREGULATION AND GLYCEMIC CONTROL? By © Susan Warren A Thesis submitted to the School of Graduate Studies in partial fulfillment of the requirements for the degree of Master of Science in Medicine (Clinical Epidemiology) Discipline of Clinical Epidemiology, Faculty of Medicine Memorial University of Newfoundland October 2018 St. John’s Newfoundland and Labrador ABSTRACT Objective: To determine if delaying a newborn’s first bath until at least 24 hours of life, as recommended by the World Health Organization, effects in-hospital breastfeeding rates, infant hypothermia rates and/or infant hypoglycemia rates. Methods: Retrospective cohort study comparing 680 infants bathed before 24 hours to 545 infants bathed after 24 hours. The primary outcome was comparison of the rates of in-hospital breastfeeding initiation and exclusive breastfeeding at discharge. Secondary outcomes were a comparison of rates of infant hypothermia and hypoglycemia. Results: Exclusive breastfeeding rates were 33% higher in the delayed bathing cohort compared to the early bathing cohort (AOR 1.334, 95% CI 1.049-1.698, p=0.019). No significant difference in breastfeeding initiation rates were observed in the total population or high-risk subgroup but in the average risk subgroup there was a significant 43% increase in breastfeeding initiation rates when bathing was delayed (AOR 1.433, 95% CI 1.008-2.039, p=0.045). Infants bathed after 24 hours were 2.5 times more likely to experience a hypothermic event than those bathed before 24 hours (AOR 2.524, 95% CI 1.239-5.142, p=0.011). No significant differences in rates of hypoglycemia were observed (AOR 0.916, 95% CI 0.421-1.994, p=0.826). Conclusions: Delaying newborn bathing was associated with increased likelihood of exclusive breastfeeding at discharge and increased rates of hypothermia. Keywords: Delayed newborn bathing, infant bathing, breastfeeding, hypothermia, hypoglycemia. ii ACKNOWLEDGEMENTS I would like to express my genuine appreciation who everyone supported me over the course of my graduate program. I wish to especially thank my supervisor Dr. Laurie Twells and my co-supervisors Dr. Leigh Anne Allwood Newhook and Dr. William Midodzi for their invested support and guidance throughout this process. The combination of encouragement and teaching I received from you have been invaluable to my success. My gratitude also extends to the members of the Breastfeeding Research Working Group. The multidisciplinary expertise of this team combined with their tremendous support and comradery have made my graduate journey a most enjoyable success. A special thanks to team members Dr. Ann Drover, Clare Bessell and Lorraine Burrage whose insight and expertise in neonatal care have guided me throughout this process. I would like to acknowledge the Perinatal Program of Newfoundland and Labrador and in particular, Phil Murphy who assisted in data collection, patient recruitment and random sampling and whose knowledge and guidance in data collection were a gift. I would like to thank the Janeway Pediatric Research Unit. In particular, Sharron Penney for her meticulous work in data collection and Rana Asnalov for her encouragement and guidance. iii I would like to acknowledge the funding from Dr. Laurie Twells, the Faculty of Medicine, the School of Graduate Studies and the Janeway Foundation’s Trainee grant that made is possible for me to pursue studies as a full-time graduate student. I would like to extend my gratitude to my supportive family. My husband Bill who has unwittingly become somewhat of a lactation expert over the past few years. My beautiful children, Avery and Ziva who believe that school is what mommies do. And a very special thank you to my mother-in-law Donna Warren who graciously cared for my two newborn children over the course of my studies. Her loving support of my family and her inherent value for education as a teacher have made it possible for me to be a successful mother and full-time student. iv TABLE OF CONTENTS ABSTRACT........................................................................................................................ ii ACKNOWLEDGEMENTS............................................................................................... iii TABLE OF CONTENTS.....................................................................................................v LIST OF TABLES............................................................................................................viii LIST OF FIGURES..............................................................................................................x LIST OF ABBREVIATIONS.............................................................................................xi Chapter 1: Introduction........................................................................................................1 1.1 Background and Rationale ..........................................................................................1 1.2 Purpose ........................................................................................................................5 1.3 Research Question........................................................................................................6 1.4 Summary......................................................................................................................6 Chapter 2: Literature Review...............................................................................................7 2.1 Recommendations for Infant Bathing .........................................................................7 2.2 Interrelated Effects of Early Newborn Bathing ..........................................................9 2.2.1 Biofluids and Olfactory Cues................................................................................11 2.2.1a Vernix Caseosa..................................................................................................11 2.2.1b Amniotic Fluid..................................................................................................15 2.2.2 Skin-to-Skin Contact and Mother-Infant Bonding Disruption..............................17 2.3 Impact of Delaying Newborn Bathing on Breastfeeding Rates.................................27 2.4 Impact of Delaying Newborn Bathing on Infant Hypothermia..................................31 2.4.1 Prevalence of Thermal Instability in Infants After Early Bathing........................33 v 2.4.2 The Effect of Bath Timing on Thermal Stability of Infants..................................36 2.5 Impact of Delaying Newborn Bathing on Infant Hypoglycemia...............................41 2.6 Summary of Gaps in the Clinical Literature..............................................................43 Chapter 3: Methods............................................................................................................45 3.1 Study Design..............................................................................................................45 3.2 Population and Sample...............................................................................................45 3.2.1 Inclusion Criteria...................................................................................................46 3.2.2 Exclusion Criteria..................................................................................................46 3.3: Statistical Methods and Sample Size Calculations...................................................48 3.4: Procedure and Variable Definitions..........................................................................48 3.4.1: Exposure Variable................................................................................................49 3.4.2: Outcome Variables...............................................................................................51 3.5 Statistical Analysis.....................................................................................................52 3.6 Ethical and Privacy Considerations............................................................................53 Chapter 4: Results .............................................................................................................54 4.1 Descriptive Statistics..................................................................................................54 4.2 Primary Analysis Significance Testing......................................................................56 4.2.1 Total Population…................................................................................................56 4.2.2: High Risk Population...........................................................................................57 4.2.3: Average Risk Population......................................................................................59 4.3: Secondary Analysis...................................................................................................61 4.4: Summary...................................................................................................................63 Chapter 5: Discussion ........................................................................................................66 vi 5.1: Characteristics of Study Population..........................................................................67 5.2: Breastfeeding Initiation (BFI) ..................................................................................67