UNIVERSITY OF HONG KONG LI KA SHING FACULTY OF MEDICINE HKU MBBS Year 3 Patient Care Project (Mother-Baby) Presentation Growth Groups 8b – 11 UGLT 2, QMH 8, October, 2011 1
UNIVERSITY OF HONG KONG LI KA SHING FACULTY OF MEDICINE Part 1Overview of Infant Growth Ivan Wong, Philip Lee, Denise So, Jennie Yick, Bernard Shum
Part 1. Overview of Infant Growth Definition of growth Phases of growth Factors affecting growth Allometric growth Measurement of growth Abnormal growth Failure to thrive Overweight 3
Growth Growth: increase in the size of the body Development: increase in function of processes related to body and mind 4
5 Phases of growth
Factors affecting growth Prenatal Maternal factors (e.g. size of mother, maternal weight, BMI, toxic exposure, nutritional state, hemodynamic status and stress) Placental factors (e.g. size, microstructure, nutrient supply) Fetal factors (e.g. genetics, nutrient and hormone production) Postnatal Genetics (maternal and paternal) Nutritional factors Hormonal functions (e.g. thyroid, growth hormone) Prenatal condition Physical health (e.g. chronic illness) Mental health (e.g. profound chronic unhappiness GH secretion↓) Socioeconomic factors 6
7 Allometric growth
Many organs/parts show disproportionate growth
at birth the head is about 25% of the body's length
but at maturity it is about 12% (or less) of its length
The genetic basis of allometric growth involves differential timing of genes; therefore, it is a form of heterochrony
8 The WHO child growth standards (http://www.who.int/childgrowth/standards/)
Body mass index
Motor development milestones
9 Correct technique matters Must be performed on a naked infant or a child dressed only in underclothing Occipitofrontal circumference is a measure of head and hence brain growth. The maximum of 3 measurements is used
10 Correct technique matters
Growth charts 11 Growth parameters should be plotted on charts Q. Will the standards be applicable to all children? A. The standards describe normal child growth under optimal environmental conditions and can be applied to all children everywhere, regardless of ethnicity, socioeconomic status and type of feeding. (http://www.who.int/childgrowth/standards/)
Interpretation of growth charts A single growth parameter should not be assessed in isolation from the other growth parameters A single observation is difficult to interpret unless there is marked discrepancy The further the parameter lies from the mean, the more likely it is pathological Serial measurements are used to show the pattern and determine the rate of growth 12
Examples of abnormal growth (1) Failure to thrive a description (not a diagnosis) applied to children whose current weight or rate of weight gain is significantly below that of other children of similar age and sex Causes: Organic (<5%) Accompanied by abnormal symptoms or signs Non-organic (>95%), e.g. Inadequate availability of food Psychosocial deprivation Neglect or child abuse 13
Examples of abnormal growth (1) Failure to thrive Investigations Most affected infants and toddlers do not require any investigations Management Multidisciplinary Paediatric dietician Clinical psychologist Social worker Nursery Carried out in primary care Increasing energy intake by dietary and behavioral modification and monitoring growth Hospital admission is usually only for severe cases 14
Examples of abnormal growth (2) 15 Obesity Obesity in children and adolescents is defined as a BMI greater than the 95th percentile Increasing major health issue Predisposing children to a wide range of medical and psychological problems in childhood and adult life Especially type 2 diabetes mellitus and cardiovascular disease
Examples of abnormal growth (2) 16 Obesity Management Sustained changes in lifestyle, e.g. healthier eating, increased physical activity, and reduction in physical inactivity difficult to achieve and even harder to maintain Cultural change in our society should be considered, e.g. removal of ‘tuck shops’ and vending machines with unhealthy food and drinks from schools Drug treatment and surgical intervention are only appropriate in a small number of children
17 Part 2 – Statistics from PCP-MB
Our Aim: Determine whether the growth of infants in HK is influenced by the following factors Mode of feeding Mode of delivery Gestational age at delivery
Why we chose these aspects for analysis: we chose these topics because: 1. we believe feeding method and feeding as a whole will have major influence on postnatal growth 2. Medicalization of pregnancy has led to change in the trend of method of delivery which may impact growth 3. Assisted delivery method may influence the age of infants at delivery which can later affect postnatal growth
Summary of the data sample
UNIVERSITY OF HONG KONG LI KA SHING FACULTY OF MEDICINE Part 2.1 Does Breast Feeding affect the initial growth rate of newborns? Cherlyle Chan, Jason Law, LEUNG Yuen Yee, LUI ShingTsun, Arthur Mak, PUK Kam Yan , Salvio Ng, Amanda Slocum, Jeffrey Tsang
24 Literature review
Literature review Fulhan J et al: Update on pediatric nutrition: Breastfeeding, infant nutrition, and growth.Curr Opin Pediatr. 2003 Jun;15(3):323-32.
Adequate for growth
Vitamins A and B6
Highly dependent on maternal stores
Sufficient in well-nourished populations
Small amount in breast milk
Depend on exogenous sources of vitamin D or sunlight for bone health
Literature review Literature review Fulhan J et al: Update on pediatric nutrition: Breastfeeding, infant nutrition, and growth.Curr Opin Pediatr. 2003 Jun;15(3):323-32.
Independent of mother’s diet
Fairly constant throughout lactation
Iron and Zinc
Endogenous stores of infants
Amount received through diet
Iron must be received from complementary foods or additional supplements after stores diminish (after 6 months)
Level of maternal zinc stores is important
Literature review Anderson AK: Association between Infant Feeding and Early Postpartum Infant Body Composition: A Pilot Prospective Study. Int J Pediatr. 2009;2009:648091. Epub 2009 Mar 12.
Aim: To compare the weight gain of infants in the early postpartum period (first 12 weeks of delivery) between newborns who were exclusively breastfed and those who were given mixed feeding
Results: Rate of both weight gain and adiposity was a little bit higher among infants who were exclusively breastfed as compared to those who received mixed feeding
Consistent with previous studies which compared exclusive breastfeeding with formula feeding
Follow-up: further examine the change in percentage body fat at 6 months and 12 months postpartum
Literature review Kramer MS et al: Breastfeeding and Infant Growth: Biology or Bias?.Pediatrics. 2002 Aug;110(2 Pt 1):343-7.
Aim: To compare between the breastfeeding promotion intervention (modeled on the WHO/UNICEF Baby-Friendly Hospital Initiative) and the control infant feeding practices
Compared infants who were weaned in the first month with those who were breastfed for the full 12 months with either at least 3 months or at least 6 months of exclusive breastfeeding
Results:Mean birth weight was significantly higher in the experimental group by 1 month of age. Difference in weight gain increased through the 3 months but declined slowly thereafter before disappearing by 12 months
This suggests that prolonged and exclusive breastfeeding has the potential in accelerating weight and length gain in the first few months without any detectable deficit by 12 months of age.
Data Analysis Data Analysis
Data Analysis The weight of FEMALE babies against age Breast-fed female babies (blue) VSFormula-fed female babies (red) Implications: Growth rate of breast-fed female babies is higher than that of formula-fed. Thereis significant evidence in the beneficial effects of breast feeding over formula feeding on growth in female babies.
Data Analysis The weight of MALE babies against age Breast-fed male babies (blue) VSFormula-fed male babies (red) Implications: The growth rate of breast-fed male babies is similar to that of formula-fed.There is no significant evidence of the beneficial effects of breast feeding on growth in male babies.
UNIVERSITY OF HONG KONG LI KA SHING FACULTY OF MEDICINE Part 2.2 Does the mode of delivery affect the initial growth rate of newborns? Keedon Wong, Becky Ma, Jonathan Chow, Ponie Lee, Kathy Lam, Ling Kong, Staccato Lau, Andrew Mak, Lee Kit Ming
33 Literature review
Literature Review Planned cesarean versus planned vaginal delivery at term: Comparison of newborn infant outcomes1 Kolas et. al (2005) American Journal of Obstetrics and Gynecology There were no significant differences in the risks for low Apgar score and neurologic symptoms. Planned vaginal delivery versus elective caesarean section in singleton term breech presentation: a study of 1116 cases2. Golfier et. al (2001).European Journal of Obstetrics & Gynecology and Reproductive Biology C-section is better for infant health but worse for maternal health in breech presentation.
Mode of Delivery and Asthma - Is There a Connection? 3 Kero et. al (2002) Pediatric Research The register study showed the cumulative incidence of asthma at the age of seven to be significantly higher in children born by caesarean section (4.2%) than in those vaginally delivered (3.3%),
Data Analysis Data Analysis
Methodology Pool of Data Assisted Vaginal Delivery Natural Vaginal Delivery Caesarean Delivery Assisted Vaginal Delivery Natural Vaginal Delivery Caesarean Delivery Growth rate of:
Growth rate of:
Growth rate of:
Any Statistical Differences? Any Statistical Differences?
Methodology Growth Rate (GR) Variable DAY 0 – Variable NEXT EARLIEST DAY WITH DATA Duration in between (Gestational Weeks) Head Circumference DAY 0 – Head Circumference DAY 10 Example Gestational Weeks in between (2)
Results GR of Body Weight t-test for equality of Means between ‘Assisted’ & ‘Natural Vaginal Delivery’ t-test for equality of Means between ‘Caesarean’ & ‘Natural Vaginal Delivery’ Difference in GR of Body Weight; p=0.585 Difference in GR of Body Length; p=0.248 Difference in GR of Head Circumference; p=0.558 Difference in GR of Body Weight; p=0.877 Difference in GR of Body Length; p=0.155 Difference in GR of Head Circumference; p=0.730 GR of Body Length Statistically Insignificant GR of Head Circumference
Discussion New Questions Literature Are there any confounding factors? Perhaps the parameters (head circumference/body weight/body length) might not be sensitive enough to document growth rate in this study? Equation for growth rate might not capture the real growth rate accurately? This is a pilot study with no other research data on the same set of parameters. 7 studies further reviewed: compared the outcomes of vaginal delivery and cesarean section by: infant health, e.g. mortality rate, risk of respiratory morbidity 1-4, birth weight5-6, and growth-related hormone measurements7. None of these studies show direct relationship between modes of delivery and growth. Limitations Variability in the duration between data points used to measure GR Low sample size Assumed linear growth of infant Reporting & selection bias Future Study How does the mode of delivery affect growth hormones levels in newborns?
UNIVERSITY OF HONG KONG LI KA SHING FACULTY OF MEDICINE Part 2.3 Does the gestational age at delivery affect the initial growth rate of newborns? Simon Chan, Tom Chow, Bernice Yu, Denise Cheng, Derek Ng, Eric Ng, Simon Yan, Cyrus Lai, Herriet Tsang
41 Literature review
Literature Review Growth of preterm infants Catch-up growth Gairdner, D., and Pearson, J. (1971) 4 phases of growth usually observed:
Phase 1: immediate postnatal weight loss.
Phase 2: (half to 1week) Rate of growth is similar to that of the foetus of comparable gestational age.
Phase 3: growth rate accelerates, much exceeds that of the foetus.
Phase 4: continue in the same percentile.
30 preterm white infants of AGA weight born <32 complete weeks of gestation were studied No significant correlations to suggest that insufficient early weight gain affected later patterns of weight. Literature: Phase 3 – Catch-up phase? Is term newborn body composition being achieved postnatally in preterm infants? Roggero et al (2009) Insufficient early weight gain in preterm babies andinfluence on weight at 12 months Davies D P and Kennedy J D, (1981) Preterm infants <30weeks gestation studied Weight, length and head circumference were smaller in the preterm group (no catch-up evident)
Assessment of Gestational Age Estimation from last menstrual period(LMP) Naegele’s rule : Add seven days and subtract three months from the LMP
Assessment of Gestational Age (2) Prenatal Ultrasonography Before visualization of the embryo 30 + Gestational sac diameter (mm) = Gestational day After visualization - Crown – rump length - Biparietal diameter, Head circumference, Femur length, Abdominal circumference
Assessment of Gestational Age (3) New Ballard Score Determine GA through Neuromuscular and Physical assessment of a newborn Physical parameters: Skin, Lanugo, Plantar surface, Breast, Eye/Ear, Genitals (M/F) Neuromuscular parameters: Posture, Square window, Arm recoil, Popliteal angle, Scarf sign, Heel to ear
……… In 530 infants, gestational age by last menstrual period was confirmed by agreement within 2 weeks with gestational age by prenatal ultrasonography (C-GLMP). For these infants, correlation between gestational age by NBS and C-GLMP was 0.97. Mean differences between gestational age by NBS and C-GLMP were 0.32 +/- 1.58 weeks and 0.15 +/- 1.46 weeks among the extremely premature infants (less than 26 weeks) and among the total population, respectively. ………
Data Analysis Data Analysis
Definition of Preterm Birth From WHO: Defined as childbirth occurring at less than 37 completed weeksor 259 days of gestation Major determinant of neonatal mortality and morbidity Has long-term adverse consequences for health
Assumptions in data analysis
Is growth rate associated with gestational age at birth? Conclusion: The lines of best fit shows that in general, there is a positive linear correlation between gestational age at delivery and rate of postnatal growth. However, R2 shows that the strength of association is (very) weak.
Closer look at such correlation This part of the table shows that the three parameters have significant and strong correlation with each other. Reflecting that there are agreement in these measurements. The table shows that the correlation between the three growth rate parameters with gestational age at birth are all statistically non-significant. Thus the small positive correlation may be spurious.
Even if there is no association, do preemies grow quicker? (catch up growth) Conclusion This shows that the rate of gain in weight, length, and head circumference are similar between preterm and full term infants.
Conclusion The difference in rate of gain in weight, length, head circumference are not significant
Looking deeper into catch up growth For males, the rate of growth for full term and preterm infants are similar. For female however , there appears to be significant difference. Significant since the 95% CI do not overlap This is strange !?
Explanation Since there is only 1 preterm female in the sample group Variance cannot be estimated (therefore not drawn on the graph) and has to be assumed equal in T test. T test shows that there is no significant difference between female premies and full-tern infants rate of growth
Summary of results Data analysis shows that there is no significant association between gestational age of delivery and postnatal rate of growth. Data shows that there is no significant difference in rate of growth between preterm and full term infants. -- No catchup growth observed.
Discussion & Limitations Disccusion It is contra-intuitive growth rate is higher in infants born at higher gestational age. Despite the correlation being very weak and statistically insignificant. Phase 3 - Catch up growth was not demonstrated. due to our growth rate estimates only reflecting the initial rate of growth during the earliest post-natal period. These estimates may be reflecting phase 2 growth so the significant acceleration has not been captured by the data. Limitations
Although significant difference in rate of growth was not apparent between full and pre-term, this may be due to:
Insufficient sample size, not enough preterm infants (particularly female), no extreme of preterm.
Growth recording was not implemented stringently.
Our assumptions that genetic factors, calories intake, living environment or health issues are the same for all infants may not be true.
UNIVERSITY OF HONG KONG LI KA SHING FACULTY OF MEDICINE Part 3Conclusion & improvement Overall
Conclusion 1.) Breast Feeding 2.) Gestational age 3.) Mode of delivery No Significant Correlation between growth rate Why?!
64 Conclusion Due to 1.) Small Sample size (<70 participants) 2.) Reporting Bias (too many missing data) ~Further Improvement of the research 1.) Using Data along with previous year PCP-MB to compare to increase sample size or to compare 2.) Trying hard to ask every pair of PCP-MB to gather as many relevant information as much as possible
Reference (1) 1. Golfier F, Vaudoyer F, Ecochard R, et al: Planned vaginal delivery versus elective caesarean section in singleton term breech presentation: a study of 1116 cases.Eur J ObstetGynecolReprod Biol. 2001;98:186-92. 2. Kero J, Gissler M, Gronlund MM, et al: Mode of delivery and asthma -- is there a connection? Pediatr Res. 2002;52:6-11. 3. Kolas T, Saugstad OD, Daltveit AK, et al: Planned cesarean versus planned vaginal delivery at term: comparison of newborn infant outcomes. Am J Obstet Gynecol. 2006;195:1538-43. 4. Morrison JJ, RennieJM,Milton PJ: Neonatal respiratory morbidity and mode of delivery at term: influence of timing of elective caesarean section. Br J ObstetGynaecol. 1995;102:101-6. 5. Lee KS, Khoshnood B, Sriram S, et al: Relationship of cesarean delivery to lower birth weight-specific neonatal mortality in singleton breech infants in the United States.Obstet Gynecol. 1998;92:769-74. 6. Naylor CD, Sermer M, Chen E, et al: Cesarean delivery in relation to birth weight and gestational glucose tolerance: pathophysiology or practice style? Toronto Trihospital Gestational Diabetes Investigators.Jama. 1996;275:1165-70. .
66 Reference (2) 7.Bird JA, Spencer JA, Mould T, et al: Endocrine and metabolic adaptation following caesarean section or vaginal delivery. Arch DisChild Fetal Neonatal Ed. 1996;74:F132-4. 8. J Cockerill, S Uthaya, C J Doré, and N Modi: Accelerated postnatal head growth follows preterm birth.ArchDis Child Fetal Neonatal Ed. 2006 May;91(3):F184-7. Epub 2006 Jan 12. 9. Luciana Friedrich, Paulo M. C. Pitrez, Renato T. Stein, Marcelo Goldani, Robert Tepper, and Marcus H. Jones: Growth Rate of Lung Function in Healthy Preterm Infants. Am J RespirCrit Care Med. 2007 Dec 15;176(12):1269-73. Epub 2007 Sep 20. 10. Paola Roggero , Maria LorellaGiannì, Orsola Amato et al: Is term newborn body composition being achieved postnatally in preterm infants? Early Hum Dev. 2009 Jun;85(6):349-52. Epub 2009 Jan 21. 11. Gairdner, D., and Pearson, J.: A Growth Chart for Premature and other Infants. Arch Dis Child. 1971 Dec;46(250):783-7. 12. Davies D P and Kennedy J D: Insufficient early weight gain in preterm babies and influence on weight at 12 months. Arch Dis Child. 1986 Jan;61(1):96
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