Epidemiology and outcome of Gastroschisis in Tasmania Dr. Gopakumar Hariharan Advanced trainee in Neonatology and Paediatrics Royal Hobart Hospital

Gastroschisis Serious congenital defect- surgery soon after birth Intestines herniation through a defect in the abdominal wall – right of umbilicus Cause – unknown- suspected vascular accident Antenatally. Predisposing factors from previous studies – young maternal age, low socio-economic class, maternal smoking and substance abuse. Fetus usually genetically normal. Has increased risk of morbidities

Objective To describe Prevalence and trend Antenatal risk factors and Outcome of neonates born with Gastroschisis.

Methods Retrospective analysis of all Gastroschisis cases in Tasmania between 1996 to 2015 (20 years) Data - Paper records from 1996 to 2005 and Digital medical records from 2006. Antenatal, natal and postnatal factors. Maternal characteristics, medical and surgical outcomes. The prevalence of gastroschisis was compared between two 10-year periods, January 1996 - December 2005(epoch 1)* and January 2006 to December 2015(epoch 2). Further analysis was done on the data collected for epoch 2. *Walwyn T, Morris P, Fenton E, Cartledge J, Parsons SJ,Dargaville PA. Epidemiology of gastroschisis and exomphalos in Tasmania 1990–2005. J. Paediatr. Child Health 2009; 45 (Suppl. 1): A63.

Statistical analysis Descriptive statistics – Median, Interquartile range Prevalence – calculated per 10,000 live births.( population data obtained from Australian Bureau of Statistics and Council of Obstetric and Paediatric Mortality and Morbidity). Confidence interval –calculated for proportions. Non parametric analysis ( Mann Whitney U test) - Comparison of medians Chi square test/Fischer exact test for categorical variables.

Results – Prevalence 58 cases of Gastroschisis during the 20-year period Epoch 1 ( 29 live births + 1 still birth = 30 cases) Epoch 2( 25 livebirths + 3 still birth = 28 cases) Overall prevalence over 20 years – 4.5/10000 live births The prevalence of gastroschisis was Epoch 1 : 4.7 per 10000( 95% CI ; 2.7 , 6.7) Epoch 2 : 4.06 per 10000 ( 95% CI ; 2.0 ,6.0) Slight decreasing trend but not significant  

Tasmanian regions – Medicare local ( regional offices- encompass 29 local government areas of Tasmania) COPMM

Regional prevalence of Gastroschisis Prevalence( cases/10000) South 4.2 ( 95% CI; 2.2, 6.2) North 4.5 ( 95% CI; 2.5, 6.5) North west 4.3 ( 95% CI; 1.3, 6.3)

Incidence Plot

Results in context – Prevalence Northern Queensland( 3.2 / 10000 livebirths) – Review of cases from 1988 to 2007 ( 59 cases) (Whitehall et al, Journal of paediatrics and child health, 2010) Victoria ( 3.42/10000 livebirths) Increasing prevalence Northern Queensland – increasing prevalence ( 0.7 to 4.8) Western Australia – 1.53 to 4.30 Victoria – 0.71 to 2.44 CDC report( 14 states) – increasing prevalence 1995 to 2005 – 3.6/10000 live births 2006 to 2012 – 4.9/10000 live births

Epoch 2 analysis- Baseline data Gestational age (median;IQR) 37 weeks( 35.5 - 38) Range: 34 to 40 weeks Birth weight (median;IQR) 2585 grams(2267 – 2878) Range: 1805 to 3740 M:F 1:1 LSCS 10 (38%) Polyhydramnios None Oligohydramnios 3 cases Maternal smoking 28%

Epoch 2( Baseline data) TPN duration( median; IQR) 21 days(15.5 – 35.5) Range : 10 to 131 days Time to start oral intake (median;IQR) 5 days( 4.5 – 7.0) Range – 2.0 to 13 days Time to full feeds(median;IQR) 16 days( 12 – 27.5) Range: 6.0 to 138 days Hospital stay(median;range) 31 days (14-138 days) Intensive care days(median;range) 20 days ( 3 – 38 days)

Results – Maternal age Majority of gastroschisis cases were diagnosed in mothers who were </=25 years Epoch 1: 72% Epoch 2 : 69% 2013 COPPM data – maternal age distribution   Epoch 1 Epoch 2 Median (IQR) 22(18.75-27.25) 24 (18.75-27.25) P = 0.93 Range 16-39 16 – 37 </=25 years 21(72%) 18(69%) P=0.8 </= 20 years 11(38%) 11(42%)

Prevalence according to maternal age Prevalence ( per 10,000) Less than 20 years 18.7 20 to 24 years 6.2 >/= 25 years 3 Increased prevalence in young maternal age ( <20 years) – statistically significant ( P – 0.0003)

Maternal smoking ( age less than 20 years) Percentage 1982 55.2 2009 43 2010 46.8 2011 35.7 2012 35.6 2013 33.4 Less than 20 years – 50% smoked during pregnancy Council of obstetric &paediatric morbidity and mortality report - 2013

Epoch 2 analysis 84.6% of neonates were born to primi gravidas. Adhesive intestinal obstruction – 4 cases ( day of presentation – 32 days to 3 years) 23% of cases had a postoperative period complicated by feed intolerance – hydrolysed or elemental formula. There were four postnatal deaths in epoch 1 and none in epoch 2. No concerns with regard to development.

Conclusions The prevalence of the condition has remained similar for the two epochs. Young primi mothers appears to be a predisposing factor for Gastroschisis although causality could not be established. Babies born with gastroschisis can expect a normal outcome with current standard of care. Long term follow up is essential as late complications are possible.

Limitations Details on still births and neonatal deaths not available for this study. Retrospective nature of the study. Small population

Relevance of study results 1) Better understanding of predisposing factors - better parental counselling 2) Need for long term follow up- complications as late as 3 years. 3) Public health research – to identify etiological factors 4) Education – teenage pregnancy, maternal smoking. 4) Quality of care- benchmarking with other centres.

Acknowledgment Dr. Tony De Paoli ( Director, Neonatology) Mr. Michael EE ( Staff specialist, Paediatric surgeon) Prof. Peter Dargaville(Staff specialist, Neonatologist) Dr. Thomas Walwyn Dr.Reeshma Pattan

Thank you