Bottle-feeding and the Risk of Pyloric Stenosis

Perinatal risk factors for infantile hypertrophic pyloric stenosis: A systematic review and meta-analysis

BACKGROUND

Infantile hypertrophic pyloric stenosis (IHPS) is one of the most common diseases that require surgical intervention amongst the paediatric population. Although the treatment and the diagnosis of pyloric stenosis are well established, the perinatal risk factors associated with it still need further investigation.

METHODS

We searched the following databases: Cochrane, Google Scholar, PubMed, and Scopus. Studies were included if they were case-control or cohort in design and studied the perinatal risk factors associated with IHPS. The quality of the included studies was assessed using the Newcastle-Ottawa scale (NOS).

RESULTS

Twenty-one articles were included in this meta-analysis, including 18,104,753 participants. Our analysis showed a significant association between IHPS and male sex (RR=2.71, 95% CI:1.93-3.78), maternal smoking (RR=1.75, 95% CI: 1.54 - 2.00), bottle-feeding (RR=1.68, 95% CI: 1.42 - 1.98), being first born (RR=1.23, 95% CI:1.07-1.40), African ethnicity (RR=0.51, 95% CI: 0.35-0.75), and cesarean section (RR=1.57, 95% CI: 1.49-1.66). On the contrary, there was no significant association between IHPS and multiple gestations, preterm labour, being born in summer, and small for gestational age (SGA).

CONCLUSION

In conclusion, our analysis showed that male sex, bottle feeding, maternal smoking and African ethnicity were significantly associated with the risk of IHPS. However, most of the included articles were retrospective in design which necessitates conducting future prospective well-designed studies to further investigate the risk factors of IHPS.

Infantile hypertrophic pyloric stenosis: maternal diabetes and perinatal exposure to non-macrolide antibiotics

OBJECTIVE

Infant exposure to macrolide antibiotics is a risk factor for infantile hypertrophic pyloric stenosis (IHPS). The aim of the study was to establish whether perinatal exposure to non-macrolide antibiotics was a risk factor for IHPS.

STUDY DESIGN

A retrospective matched case-control study was performed using a database including all children born at Soroka University Medical Centre between 2006 and 2018. Cases and controls were compared using Student T-test and multiple logistic regression.

RESULT

Of 189 461 children in the database, 63 infants were diagnosed with IHPS and underwent pyloromyotomy. There was no association between non-macrolide antibiotic exposure and IHPS. Maternal diabetes (DM) had an adjusted odds ratio for infants developing IHPS of 4.53 (p = 0.004).

CONCLUSION

The lack of association between exposure to non-macrolide antibiotics and IHPS suggests a quality unique to macrolides. An association between DM and IHPS may suggest elevated levels of IGF-1 have a role.

Factors associated with pyloric hypertrophy severity and post-operative feeding and nutritional recovery in infantile hypertrophic pyloric stenosis

BACKGROUND

To examine factors that affect the severity of pyloric hypertrophy, post-operative feeding and nutritional recovery in infantile hypertrophic pyloric stenosis (IHPS).

METHODS

Medical records of infants diagnosed with IHPS at a single tertiary center between 2009 and 2018 were retrospectively reviewed. Clinical characteristics, biochemistry data and outcome were assessed for their association with the severity of pyloric hypertrophy and post-operative recovery. Nutritional recovery was assessed using weight-for-age status improvement after surgery.

RESULTS

Eighty-five patients were recruited in this study. The mean pre-operative weight-for-age percentile was 18.2. Elevated bicarbonate was positively correlated with symptom duration (p = 0.007). Pyloric muscle thickness was significantly correlated with age, weight, and symptom duration (p = 0.004, 0.003, 0.008, respectively). The mean weight-for-age percentile increased to 41.6 by post-operative weeks 6-8. Pyloric muscle thickness was negatively correlated with nutritional recovery by post-operative weeks 6-8 (p = 0.003). In multivariable analysis, pyloric length related to nutritional recovery at week 1-2 postoperatively (OR = 1.42, p = 0.030, 95% CI = 0.03-1.94), and pyloric muscle thickness related to nutritional recovery at week 6-8 postoperatively (OR = 4.08, p = 0.032, 95% CI = 1.13-14.7).

CONCLUSION

Our study indicated that favorable nutritional outcome and successful weight gain was observed 6-8 weeks after surgery in children with IHPS. Pyloric muscle thickness positively correlated with age, weight, symptom duration, and favorable nutritional recovery. Serum bicarbonate showed a positive correlation with symptom duration.

Diagnostic Accuracy of Acid-Base Status in Infants with Hypertrophic Pyloric Stenosis

Background: Hypertrophic pyloric stenosis is a condition in newborns in which the hypertrophic pyloric muscle causes gastric obstructive symptoms of progressive vomiting leading to hypochloremic hypokalemic metabolic alkalosis. The main aim of the research was to assess whether, based on the acid-base status, we can distinguish newborns who vomit due to pylorostenosis, compared with newborns who vomit for other unspecific reasons. Methods: The electronic records of patients in the hospital information system treated under the diagnosis Q40.0 (Congenital hypertrophic pyloric stenosis) (n = 69/included in the study = 53) in the period from 1 January 2014 to 1 January 2022 were reviewed retrospectively. For the purposes of the control group, the electronic records of patients treated in the emergency department with a diagnosis of R11.0 (Nausea and vomiting) (n = 53) without an established cause were randomly reviewed. In addition to the main aim, other research outcomes were to determine differences between groups in the following variables: duration of symptoms, family history, birth (preterm, term, post-term), birth weight, weight during examination, difference between birth weight and weight during an examination, type of vomiting, the thickness of the muscle wall and its length, and to calculate whether there is a correlation between the thickness and length of the pylorus muscle and the duration of vomiting in relation to variables from acid-base status. Results: In relation to the variables of interest between the groups, statistically significant differences were observed in the duration of symptoms (Mdn 4 vs. 2 days, p = 0.002), weight at examination (Mean 3880 vs. 4439 g, p = 0.001), difference in weight between birth and examination (Mean 374 vs. 1010 g, p < 0.0001), and type of vomiting (explosive 45 vs. 22, p = 0.023). In the acid-base status between the groups, a statistically significant difference was recorded for pH (Mdn 7.457 vs. 7.422, p < 0.0001), bicarbonate (Mdn 25 vs. 23 mmol/L, p = 0.000), total carbon dioxide (Mdn 25 vs. 24 mmol/L, p = 0.011), base excess (Mdn 0.8 vs. −1.3 mmol/L, p = 0.000), potassium (Mdn 5 vs. 5.3 mmol/L, p = 0.006), ionized calcium (Mdn 1.28 vs. 1.31 mmol/L, p = 0.011), and glucose (Mdn 4.5 vs. 4.9 mmol/L, p = 0.007). Regardless of the group, the correlations between the duration of vomiting (r = 0.316, p = 0.021 vs. r = 0.148, p = 0.290) and the thickness (r = 0.190, p = 0.172) and length (r = 0.142, p = 0.311) of the pylorus muscle in relation to pH did not exist or were weak. Conclusions: In a world where radiological methods are not equally available everywhere, with promising acid-base indicators, prospective multicenter studies and meta-analyses must be pursued in the future in order not to miss the possible much greater diagnostic potential of acid-base status.

Spatial distribution and determinants of bottle feeding among children 0-23 months in Ethiopia: spatial and multi-level analysis based on 2016 EDHS

Background

Bottle feeding is associated with diarrheal disease morbidity and mortality and risk of pyloric stenosis, especially in developing countries. Even though, World Health Organization (WHO) recommended avoiding bottle feeding among children, still higher magnitude was reported in developing countries. This study aimed to assess the spatial distribution and determinants of bottle feeding among children 0-23 months in Ethiopia.

Methods

This study was conducted based on Ethiopian Demographic and Health Surveys data (EDHS). The data were weighted using sampling weight for probability sampling and non-response to restore the representativeness of the data and get valid statistical estimates. Then a total of 4,275 weighted samples of under two years children were used to investigate the study. The data were cleaned using MS excel and extracted and analyzed using STATA V.16 software. A multilevel binary logistic regression model was fitted. P-value < 0.05 was taken to declare statistical significance. A spatial analysis was done using ArcGIS and SaTScan software.

Results

The prevalence of bottle feeding practice among under two years children in Ethiopia were 13.5% (95%CI: 11.16, 15.29) and ranges from the lowest 5.16% (95% CI: 3.28, 78.73) Amhara region to the highest 55.98% (95% CI: 47.98, 61.46) Addis Ababa region. Women with secondary and above education status [AOR=2.49; 95%CI; 1.66, 3.74], women from richest household [AOR=1.33; 95%CI; 1.01, 1.78], child 12-23 months age [AOR= 1.59; 95%CI; 1.23, 2.05], multiple birth [AOR=4.30; 95%CI; 1.88, 9.84], rural residence [AOR=0.49; 95%CI; 0.16, 0.82] and large central region [AOR= 0.15; 95%CI; 0.08, 0.27] have significantly associated with bottle feeding. Addis Ababa, Central Oromia, Dire Dewa, Somali and Harari regions were the hot spot areas for bottle feeding practice among under two years children.

Conclusion and recommendations

The prevalence of bottle feeding practices in Ethiopia is relatively moderate. Maternal education, wealth index, child age, multiple births, residence and region were significant predictors of bottle feeding. These findings highlight that, the Ministry of Health Ethiopia (MOH), policymakers, and other stakeholders had better give prior attention to preventable factors such as empowering women, enhancing household wealth status to decreasing bottle feeding practice in Ethiopia.

Infantile hypertrophic pyloric stenosis in Bosnia and Herzegovina: A retrospective cohort study from the largest tertiary care facility

BACKGROUND

Infantile hypertrophic pyloric stenosis (IHPS) is the most common condition requiring surgery in infancy, but the etiology of IHPS is still unclear. The study aimed to analyze the epidemiological and clinical features of the infants with IHPS in our setting and determine the yearly trends in IHPS incidence in the Sarajevo Canton between 2007 and 2016.

METHODS

We retrospectively analyzed epidemiologic, clinical, and operative data of all infants undergoing pyloromyotomy for IHPS over ten years in the largest tertiary care facility in Bosnia and Herzegovina.

RESULTS

Fifty-three IHPS patients were diagnosed, yielding an overall incidence of 1.17 per 1000 live births (1.25 and 1.09 cases in 2007-2011 and 2012-2016, respectively). IHPS was more prevalent among male infants (ratio 6.6:1, p < 0.001). The mean age at onset of symptoms was 39.6 days (range, 17-107 days). The estimated median time from symptoms onset to hospitalization was 11 days (range, 1-17 days). The mean age at diagnosis was significantly longer in premature infants compared with term infants (p = 0.003). Both first-born rank and bottle-feeding were significantly associated with IHPS (p = 0.001 and p = 0.04, respectively). No seasonal variation associated with IHPS was detected (p = 0.25). No evidence was found of differences in the incidence of IHPS related to maternal age (p = 0.24) and smoking (p = 0.59).

CONCLUSION

Our data indicate a declining trend and provide insights into the clinical characteristics of IHPS in Bosnia and Herzegovina. Most of the obtained results are in line with the published data and could improve the quality of local pediatric services.

Nitrite in breast milk: roles in neonatal pathophysiology

Dietary nitrate has beneficial effects on health maintenance and prevention of lifestyle-related diseases in adulthood by serving as an alternative source of nitric oxide (NO) through the enterosalivary nitrate-nitrite-NO pathway, particularly when endogenous NO generation is lacking due to vascular endothelial dysfunction. However, this pathway is not developed in the early postnatal period due to a lack of oral commensal nitrate-reducing bacteria and less saliva production than in adults. To compensate for the decrease in nitrite during this period, colostrum contains the highest amount of nitrite compared with transitional, mature, and even artificial milk, suggesting that colostrum plays an important role in tentatively replenishing nitrite, in addition to involving a nutritional aspect, until the enterosalivary nitrate-nitrite-NO pathway is established. Increasing evidence demonstrates that breast milk rich in nitrite can be effective in the prevention of neonatal infections and gastrointestinal diseases such as infantile hypertrophic pyloric stenosis and necrotizing enterocolitis, suggesting that breastfeeding is advantageous for newborns at risk, given the physiological role of nitrite in the early postnatal period. IMPACT: The aim of this review is to discuss the physiological roles of nitrite in breast milk and its implications for neonates. Nitrite in breast milk may compensate for the decrease in nitrite during the early neonatal period until the enterosalivary nitrate-nitrite-nitric oxide pathway is established. Breast milk rich in nitrite may be effective in the prevention of neonatal infections and gastrointestinal diseases by providing nitric oxide bioavailability.

Integrating genetics with newborn metabolomics in infantile hypertrophic pyloric stenosis

INTRODUCTION

Infantile hypertrophic pyloric stenosis (IHPS) is caused by hypertrophy of the pyloric sphincter muscle.

OBJECTIVES

Since previous reports have implicated lipid metabolism, we aimed to (1) investigate associations between IHPS and a wide array of lipid-related metabolites in newborns, and (2) address whether detected differences in metabolite levels were likely to be driven by genetic differences between IHPS cases and controls or by differences in early life feeding patterns.

METHODS

We used population-based random selection of IHPS cases and controls born in Denmark between 1997 and 2014. We randomly took dried blood spots of newborns from 267 pairs of IHPS cases and controls matched by sex and day of birth. We used a mixed-effects linear regression model to evaluate associations between 148 metabolites and IHPS in a matched case-control design.

RESULTS

The phosphatidylcholine PC(38:4) showed significantly lower levels in IHPS cases (P = 4.68 × 10^-8) as did six other correlated metabolites (four phosphatidylcholines, acylcarnitine AC(2:0), and histidine). Associations were driven by 98 case-control pairs born before 2009, when median age at sampling was 6 days. No association was seen in 169 pairs born in 2009 or later, when median age at sampling was 2 days. More IHPS cases than controls had a diagnosis for neonatal difficulty in feeding at breast (P = 6.15 × 10^-3). Genetic variants known to be associated with PC(38:4) levels did not associate with IHPS.

CONCLUSIONS

We detected lower levels of certain metabolites in IHPS, possibly reflecting different feeding patterns in the first days of life.

Does Maternal Omega 3 Supplementation Protect Against Infantile Hypertrophic Pyloric Stenosis?

OBJECTIVES

Infantile hypertrophic pyloric stenosis (IHPS) is potentially life threatening. The etiology of IHPS remains unknown and many risk factors have been reported. We aimed to assess the prevalence of known risk factors and investigate maternal nutrition and habits as possible additional risk factors for IHPS.

METHODS

This case-control study includes mothers of infants diagnosed with IHPS and control mothers of infants, age 2 to 11 months, hospitalized in the pediatric department due to other conditions. Cases of IHPS were identified by review of all infants diagnosed with IHPS and operated upon in 2010 to 2016 at 2 major hospitals in central Israel. Data regarding potential risk factors were collected via questionnaires in both study groups.

RESULTS

Sixty-six cases and 67 controls were included in the study. Maternal omega 3 supplement consumption during pregnancy was significantly less common among cases of IHPS as compared with controls (P = 0.031). Consumption of omega 3 supplement was defined as consumption of at least 1 to 2 per week during the pregnancy period. Following adjustment for known risk factors, including male sex and maternal smoking, maternal omega 3 supplement consumption remained associated with a significantly lower risk of developing IHPS (odds ratio = 0.303, 95% confidence interval 0.111-0.828, P = 0.02).

CONCLUSIONS

Maternal omega 3 supplement consumption during pregnancy was associated with a significantly reduced risk of IHPS. Further studies are needed to support these results and investigate possible mechanisms of the effect of omega 3.

Low socioeconomic status and formula feeding directly correlate with increased incidence of hypertrophic pyloric stenosis

PURPOSE

The purpose of this analysis was to determine if a correlation exists between socioeconomic status (SES) and pyloric stenosis (PS) as well as between PS and feeding method.

METHODS

Data was collected retrospectively from the electronic medical record. Patients were included if they resided in a county in Illinois where our institution maintains >10% visit share, were < 1 year in age, and received a pyloromyotomy from January 2011 to May 2018. Patient addresses were geocoded and merged with county and tract-level census data. A control group was matched on gender, race, tract level, median household income (MHI), and age. Feeding method for each group was collected. Univariate analysis and multivariate analyses were employed.

RESULTS

SES was explored using MHI. After controlling for gender, age, race, and institution adjusted tract size, the association between MHI and pyloromyotomy remained significant. As MHI decreased, the odds of having a PS case increased. Additionally, the PS incidence rate increased as MHI decreased. Patients who were exclusively formula fed were more likely to have PS.

CONCLUSION

Pyloric stenosis had a direct correlation with SES as defined by MHI. As MHI decreased, the rates of PS increased. In addition, breastfeeding was protective, independent of MHI.

TYPE OF STUDY

Prognosis study.

LEVEL OF EVIDENCE

Level II.

Genome-wide meta-analysis identifies BARX1 and EML4-MTA3 as new loci associated with infantile hypertrophic pyloric stenosis

Infantile hypertrophic pyloric stenosis (IHPS) is a disorder of young infants with a population incidence of ∼2/1000 live births, caused by hypertrophy of the pyloric sphincter smooth muscle. Reported genetic loci associated with IHPS explain only a minor proportion of IHPS risk. To identify new risk loci, we carried out a genome-wide meta-analysis on 1395 surgery-confirmed cases and 4438 controls, with replication in a set of 2427 cases and 2524 controls. We identified and replicated six independent genomic loci associated with IHPS risk at genome wide significance (P < 5 × 10-8), including novel associations with two single nucleotide polymorphisms (SNPs). One of these SNPs, rs6736913 [odds ratio (OR) = 2.32; P = 3.0 × 10-15], is a low frequency missense variant in EML4 at 2p21. The second SNP, rs1933683 (OR = 1.34; P = 3.1 × 10-9) is 1 kb downstream of BARX1 at 9q22.32, an essential gene for stomach formation in embryogenesis. Using the genome-wide complex trait analysis method, we estimated the IHPS SNP heritability to be 30%, and using the linkage disequilibrium score regression method, we found support for a previously reported genetic correlation of IHPS with lipid metabolism. By combining the largest collection of IHPS cases to date (3822 cases), with results generalized across populations of different ancestry, we elucidate novel mechanistic avenues of IHPS disease architecture.

Prevalence of selected birth defects by maternal nativity status, United States, 1999-2007

OBJECTIVES

We investigated differences in prevalence of major birth defects by maternal nativity within racial/ethnic groups for 27 major birth defects.

METHODS

Data from 11 population-based birth defects surveillance systems in the United States including almost 13 million live births (approximately a third of U.S. births) during 1999-2007 were pooled. We calculated prevalence estimates for each birth defect for five racial/ethnic groups. Using Poisson regression, crude and adjusted prevalence ratios (aPRs) were also calculated using births to US-born mothers as the referent group in each racial/ethnic group.

RESULTS

Approximately 20% of case mothers and 26% of all mothers were foreign-born. Elevated aPRs for infants with foreign-born mothers were found for spina bifida and trisomy 13, 18, and 21, while lower prevalence patterns were found for pyloric stenosis, gastroschisis, and hypospadias.

CONCLUSIONS

This study demonstrates that birth defects prevalence varies by nativity within race/ethnic groups, with elevated prevalence ratios for some specific conditions and lower prevalence for others. More detailed analyses focusing on a broader range of maternal behaviors and characteristics are required to fully understand the implications of our findings.

Safety of azithromycin in infants under six months of age in Niger: A community randomized trial

BACKGROUND

Mass azithromycin distribution reduces under-5 child mortality. Trachoma control programs currently treat infants aged 6 months and older. Here, we report findings from an infant adverse event survey in 1-5 month olds who received azithromycin as part of a large community-randomized trial in Niger.

METHODS AND PRINCIPAL FINDINGS

Active surveillance of infants aged 1-5 months at the time of treatment was conducted in 30 randomly selected communities from within a large cluster randomized trial of biannual mass azithromycin distribution compared to placebo to assess the potential impact on child mortality. We compared the distribution of adverse events reported after treatment among azithromycin-treated versus placebo-treated infants. From January 2015 to February 2018, the caregivers of 1,712 infants were surveyed. Approximately one-third of caregivers reported at least one adverse event (azithromycin: 29.6%, placebo: 34.3%, risk ratio [RR] 0.86, 95% confidence interval [CI] 0.68 to 1.10, P = 0.23). The most commonly reported adverse events included diarrhea (azithromycin: 19.3%, placebo: 28.1%, RR 0.68, 95% CI 0.49 to 0.96, P = 0.03), vomiting (azithromycin: 15.9%, placebo: 21.0%, RR 0.76, 95% CI 0.56 to 1.02, P = 0.07), and skin rash (azithromycin: 12.3%, placebo: 13.6%, RR 0.90, 95% CI 0.59 to 1.37, P = 0.63). No cases of infantile hypertrophic pyloric stenosis were reported.

CONCLUSIONS

Azithromycin given to infants aged 1-5 months appeared to be safe. Inclusion of younger infants in larger azithromycin-based child mortality or trachoma control programs could be considered if deemed effective.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02048007.

Safety of azithromycin in infants under six months of age in Niger: A community randomized trial

BACKGROUND

Mass azithromycin distribution reduces under-5 child mortality. Trachoma control programs currently treat infants aged 6 months and older. Here, we report findings from an infant adverse event survey in 1-5 month olds who received azithromycin as part of a large community-randomized trial in Niger.

METHODS AND PRINCIPAL FINDINGS

Active surveillance of infants aged 1-5 months at the time of treatment was conducted in 30 randomly selected communities from within a large cluster randomized trial of biannual mass azithromycin distribution compared to placebo to assess the potential impact on child mortality. We compared the distribution of adverse events reported after treatment among azithromycin-treated versus placebo-treated infants. From January 2015 to February 2018, the caregivers of 1,712 infants were surveyed. Approximately one-third of caregivers reported at least one adverse event (azithromycin: 29.6%, placebo: 34.3%, risk ratio [RR] 0.86, 95% confidence interval [CI] 0.68 to 1.10, P = 0.23). The most commonly reported adverse events included diarrhea (azithromycin: 19.3%, placebo: 28.1%, RR 0.68, 95% CI 0.49 to 0.96, P = 0.03), vomiting (azithromycin: 15.9%, placebo: 21.0%, RR 0.76, 95% CI 0.56 to 1.02, P = 0.07), and skin rash (azithromycin: 12.3%, placebo: 13.6%, RR 0.90, 95% CI 0.59 to 1.37, P = 0.63). No cases of infantile hypertrophic pyloric stenosis were reported.

CONCLUSIONS

Azithromycin given to infants aged 1-5 months appeared to be safe. Inclusion of younger infants in larger azithromycin-based child mortality or trachoma control programs could be considered if deemed effective.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02048007.

Infantile Hypertrophic Pyloric Stenosis: An Epidemiological Review

Infantile hypertrophic pyloric stenosis (IHPS) is the most common gastrointestinal disease among infants. IHPS occurs as an isolated condition or together with other congenital anomalies. Association with genetic and environmental factors, bottle feeding, younger maternal age, maternal smoking, and erythromycin administration in the first two weeks of life has been shown. Familial aggregation has been described and a family history is seen in 47.9 percent of siblings. Infants typically present with projectile vomiting associated with symptoms of failure to thrive. An olive-like mass palpable in the right upper abdominal quadrant is being reported less frequently because of earlier diagnosis by ultrasound. IHPS is generally corrected through laparoscopic pyloromyotomy. Endoscopic pyloric balloon dilation is a novel alternative. Further studies on different populations, the general population, and familial segregation to determine the prevalence, influence, and mode of familial aggregation and correlation with environmental factors are needed to determine the etiology of IHPS.

Pyloric stenosis: an enigma more than a century after the first successful treatment

Despite hypertrophic pyloric stenosis (HPS) being one of the most frequently treated pediatric surgical conditions, its etiology remains incompletely understood. We review the diagnosis and treatment of this condition with an emphasis on the evolution of surgical techniques that led to laparoscopic pyloromyotomy, the most frequently performed technique for HPS today. In addition, we review key developments in the understanding of HPS etiology and treatment, including the postulated etiology of work-induced hypertrophy of the pylorus, its association with prokinetic macrolide antibiotics, and the emerging role of atropine sulfate as a medical treatment for HPS or a rescue treatment for incomplete myotomy.

Infantile hypertrophic pyloric stenosis - Our experience and challenges in a developing country

BACKGROUND

This study aims to evaluate the experience and challenges in managing patients with infantile hypertrophic pyloric stenosis (IHPS).

PATIENTS AND METHODS

From January 2007 to December 2015, data from patients with IHPS were retrospectively acquired and analyzed using SPSS version 15. Pearson correlation used to assess linear relationships and Student t-test to compare means. P < 0.05 was taken as statistically significant. Results were expressed as percentages, means ± standard deviation and illustrated in tables and graphs.

RESULTS

Twenty-six cases were managed with the mean age at diagnosis of 49.16 ± 21.4 days. Mean birth weight was 3.7 kg and mean weight at presentation was 3.3 kg. Firstborn was affected in 29%; 91% were term deliveries; 9% were post-term; none was preterm; and 36% were exclusively breastfed. Mean duration of symptoms was 25.6 ± 18.9 days. Hyponatraemia was seen in 36%, hypokalaemia 37.5%, alkalosis 35% and hypochloraemia 62%. Mean pyloric tumour length was 22.85 ± 6.56 mm and pyloric wall thickness 5.51 ± 1.36 mm. There was a significant correlation between duration of symptoms and serum potassium level (R = -0.6326, P = 0.002). Mean symptom duration in patients with hypokalaemia was 39.88 ± 23.41 days and without hypokalaemia 17.15 ± 9.78 days (P = 0.006). Mean hospital stay was 9.45 ± 3.27 days. Four patients developed four complications and three patients died (11.5%). Mean age at presentation for pre-operative mortalities was 84 ± 39 days and 46 ± 17.98 days for others (P = 0.015).

CONCLUSIONS

IHPS presents late in our environment and occurs mainly in term males. There is a significant positive relationship between duration of symptoms and serum potassium level and the mean duration of symptoms was significantly longer in those with hypokalaemia. Pre-operative mortality was significantly associated with longer duration of symptoms.

Advances in paediatric gastroenterology

Recent developments in paediatric gastrointestinal surgery have focused on minimally invasive surgery, the accumulation of high-quality clinical evidence, and scientific research. The benefits of minimally invasive surgery for common disorders like appendicitis and hypertrophic pyloric stenosis are all supported by good clinical evidence. Although minimally invasive surgery has been extended to neonatal surgery, it is difficult to establish its role for neonatal disorders such as oesophageal atresia and biliary atresia through clinical trials because of the rarity of these disorders. Advances in treatments for biliary atresia and necrotising enterocolitis have been achieved through specialisation, multidisciplinary management, and multicentre collaboration in research; similarly robust clinical evidence for other rare gastrointestinal disorders is needed. As more neonates with gastrointestinal diseases survive into adulthood, their long-term sequelae will also need evidence-based multidisciplinary care. Identifying cures for long-term problems of a complex developmental anomaly such as Hirschsprung's disease will rely on unravelling its pathogenesis through genetics and the development of stem-cell therapy.

Perinatal risk factors for infantile hypertrophic pyloric stenosis: A meta-analysis

BACKGROUND

Infantile hypertrophic pyloric stenosis (IHPS) is the most common surgical cause of nonbilious vomiting in infancy. The etiology of IHPS is not completely understood. Hence, we performed a meta-analysis to investigate the association between perinatal factors and IHPS onset.

METHODS

The MEDLINE, EMBASE, PubMed and Cochrane Library databases were searched for studies published in English before December 2016. The combined odd ratios (ORs) and 95% confidence intervals (CIs) were calculated using random-effects models.

RESULTS

Fifteen studies were included. Several perinatal factors, including first-born (OR 1.19, 95% CI: 1.07-1.33), cesarean section delivery (OR 1.63, 95% CI: 1.53-1.73), preterm birth (OR 1.37, 95% CI: 1.12-1.67), and bottle-feed (OR 2.46, 95% CI: 1.76-3.43), were significantly associated with the IHPS onset. Among these, bottle-feed was the most significantly risk factor for IHPS onset. Although few studies have evaluated the relationship between perinatal factors and IHPS, they have major limitations including retrospective collection of data on perinatal events and testing of multiple hypotheses without appropriate statistical corrections.

CONCLUSIONS

First-born, cesarean section delivery, preterm birth, and bottle-feed are associated with the development of IHPS. Well-designed future studies are needed to help understand the etiology of IHPS.

TYPE OF STUDY

Systematic reviews and meta-analyses.

LEVEL OF EVIDENCE

Level III.

Epidemiological and clinical characteristics of 304 patients with infantile hypertrophic pyloric stenosis in Anhui Province of East China, 2012-2015

OBJECTIVE

To analyze the clinical and epidemiological features of patients with infantile hypertrophic pyloric stenosis (IHPS) so as to provide scientific evidence for diagnosis and prevention of IHPS.

METHODS

We performed a retrospective study of infants with IHPS diagnosed from 2012 to 2015 at Anhui Provincial Children's Hospital. Demographic characteristics and clinical data were collected.

RESULTS

Three hundred four patients (264 males and 40 females) were studied, of which 94.7% were full term and 75.7% were bottle fed or mixed fed; 16.8% of the patients had other congenital malformations in combination with IHPS. The proportion of IHPS cases with hyponatremia, hypokalemia, and hypochloremia was 18.4%, 12.5%, and 53.9%. A negative correlation was found between duration of disease and serum electrolytes. The mean pyloric muscle thickness, pyloric length, and diameter were 4.8 ± 0.7 mm, 19.4 ± 2.5 mm, and 13.3 ± 1.8 mm, respectively. There were significant differences in muscle thickness, pyloric length, and diameter between short (≤14 d) and long (>14 d) durations of disease. All patients underwent pyloromyotomy, and postoperative recovery was good.

CONCLUSIONS

IHPS occurs mainly in male, full-term, bottle-fed or mixed-fed infants. Patients with long duration of disease were more likely to develop electrolyte disorder and thicker muscle layer. More attention should be paid to early discovery and diagnosis, which will help to improve the curative effect and prognosis of IHPS.

Intestinal microbiota as a tetrahydrobiopterin exogenous source in hph-1 mice

Tetrahydrobiopterin (BH4) is a cofactor of a number of regulatory enzymes. Although there are no known BH4 exogenous sources, the tissue content of this biopterin increases with age in GTP cyclohydrolase 1-deficient hyperphenylalaninemia-1 (hph-1) mice. Since certain bacteria are known to generate BH4, we hypothesize that generation of this biopterin by the intestinal microbiota contributes to its tissue increase in hph-1 adult mice. The goal of this study was to comparatively evaluate hph-1 mice and wild-type C57Bl/6 controls for the presence of intestinal BH4-producing bacteria. Newborn and adult mice fecal material was screened for 6-pyruvoyltetrahydropterin synthase (PTPS-2) an enzyme only present in BH4-generating bacteria. Adult, but not newborn, wild-type control and hph-1 mouse fecal material contained PTPS-2 mRNA indicative of the presence of BH4-generating bacteria. Utilizing chemostat-cultured human fecal bacteria, we identified the PTPS-2-producing bacteria as belonging to the Actinobacteria phylum. We further confirmed that at least two PTPS-2-producing species, Aldercreutzia equolifaciens and Microbacterium schleiferi, generate BH4 and are present in hph-1 fecal material. In conclusion, intestinal Actinobacteria generate BH4. This finding has important translational significance, since manipulation of the intestinal flora in individuals with congenital biopterin deficiency may allow for an increase in total body BH4 content.

Contemporary management of pyloric stenosis

Hypertrophic pyloric stenosis is a common surgical cause of vomiting in infants. Following appropriate fluid resuscitation, the mainstay of treatment is pyloromyotomy. This article reviews the aetiology and pathophysiology of hypertrophic pyloric stenosis, its clinical presentation, the role of imaging, the preoperative and postoperative management, current surgical approaches and non-surgical treatment options. Contemporary postoperative feeding regimens, outcomes and complications are also discussed.

Formula-feeding and hypertrophic pyloric stenosis: is there an association? A case-control study

BACKGROUND

The etiology of infantile hypertrophic pyloric stenosis (HPS) is not fully understood. The objective of this study was to determine whether formula-feeding is associated with increased incidence.

METHODS

This case-control study included HPS cases and controls admitted between 1992 and 2012. Demographic data including feeding method were collected from patient charts and analyzed.

RESULTS

We identified 882 HPS cases and 955 controls. The highest incidence of HPS presentation was in summer (P=0.0028). Infants with HPS were more likely to have been exclusively formula-fed, have a family history of HPS, and be male compared to infants in the control group (P<0.001); they were also more likely to live in rural areas, although not significantly so. After adjusting for family history, sex, place of residence, and season of presentation, exclusively formula-fed infants were 1.36 times more likely to develop HPS compared with exclusively breastfed infants (RR 1.36, 95% CI 1.18-1.57, P<0.005).

CONCLUSIONS

Formula-feeding is associated with significantly increased risk of HPS. Further investigation may help to determine the components of formula that simulate hypertrophy of the pylorus muscle, or the components of breast milk that are protective, as well as other influencing factors.

LEVEL OF EVIDENCE

3b.

White paper on guidelines concerning enteric nervous system stem cell therapy for enteric neuropathies

Over the last 20 years, there has been increasing focus on the development of novel stem cell based therapies for the treatment of disorders and diseases affecting the enteric nervous system (ENS) of the gastrointestinal tract (so-called enteric neuropathies). Here, the idea is that ENS progenitor/stem cells could be transplanted into the gut wall to replace the damaged or absent neurons and glia of the ENS. This White Paper sets out experts' views on the commonly used methods and approaches to identify, isolate, purify, expand and optimize ENS stem cells, transplant them into the bowel, and assess transplant success, including restoration of gut function. We also highlight obstacles that must be overcome in order to progress from successful preclinical studies in animal models to ENS stem cell therapies in the clinic.

Association of prematurity with the development of infantile hypertrophic pyloric stenosis

BACKGROUND

Infantile hypertrophic pyloric stenosis (IHPS) has several known risk factors. The association between prematurity and IHPS and the timeline of presentation are poorly defined. Our aim was to evaluate the associations between IHPS and prematurity.

METHODS

We performed a retrospective cohort study of 1,074,236 children born between June 2001 and April 2012 in the US Military Health System. IHPS cases and gestational ages (GA) were identified using billing codes. Additional risk factors for IHPS were controlled for in a multivariable logistic regression model.

RESULTS

The incidence of IHPS was 2.99 per 1,000 in preterm infants and 2.25 per 1,000 in full term (relative risk (RR) = 1.33, 95% confidence interval (CI) 1.16-1.54). The adjusted odds ratio for prematurity was 1.26 (95% CI 1.08-1.46). The median (interquartile range (IQR)) chronological age at presentation was 40 d (30-56) in preterm infants vs. 33 d (26-45) in full term (P < 0.001). Median postmenstrual age at presentation was 42 wk in preterm infants (40-42) vs. 45 wk (44-46) in full term (P < 0.001).

CONCLUSION

Prematurity is associated with IHPS. Premature infants develop IHPS at a later chronological age, but earlier postmenstrual age, than term infants. Providers should have an increased concern for IHPS development in premature infants.

Infantile hypertrophic pyloric stenosis (IHPS): a study of its pathophysiology utilizing the newborn hph-1 mouse model of the disease

Infantile hypertrophic pyloric stenosis (IHPS) is a common disease of unknown etiology. The tetrahydrobiopterin (BH4)-deficient hyperphenylalaninemia-1 (hph-1) newborn mouse has a similar phenotype to the human condition. For hph-1 and wild-type control animals, pyloric tissue agonist-induced contractile properties, reactive oxygen species (ROS) generation, cGMP, neuronal nitric oxide synthase (nNOS) content, and Rho-associated protein kinase 2 (ROCK-2) expression and activity were evaluated. Primary pyloric smooth muscle cells from wild-type newborn animals were utilized to evaluate the effect of BH4 deficiency. One-week-old hph-1 mice exhibited a fourfold increase (P < 0.01) in the pyloric sphincter muscle contraction magnitude but similar relaxation values when compared with wild-type animals. The pyloric tissue nNOS expression and cGMP content were decreased, whereas the rate of nNOS uncoupling increased (P < 0.01) in 1-wk-old hph-1 mice when compared with wild-type animals. These changes were associated with increased pyloric tissue ROS generation and elevated ROCK-2 expression/activity (P < 0.05). At 1-3 days of age and during adulthood, the gastric emptying rate of the hph-1 mice was not altered, and there were no genotype differences in pyloric tissue ROS generation, nNOS expression, or ROCK-2 activity. BH4 inhibition in pyloric smooth muscle cells resulted in increased ROS generation (P < 0.01) and ROCK-2 activity (P < 0.05). Oxidative stress upregulated ROCK-2 activity in pyloric tissue, but no changes were observed in newborn fundal tissue in vitro. We conclude that ROS-induced upregulation of ROCK-2 expression accounts for the increased pyloric sphincter tone and nNOS downregulation in the newborn hph-1 mice. The role of ROCK-2 activation in the pathogenesis of IHPS warrants further study.

Donor milk in the newborn nursery at the University of Iowa Children's Hospital

There is a paucity of literature on the topic of banked donor breastmilk use for healthy newborns. Herein, we describe two cases demonstrating the day-to-day medically indicated use of pasteurized, banked donor breastmilk in the University of Iowa Children's Hospital newborn nursery. These cases may inform scientific opinion about the role of banked donor milk for healthy newborns and may also facilitate research on the use of banked donor milk for this population.

Etiology and non-surgical treatment of pyloric obstruction

Pyloric stenosis is a common type of upper gastrointestinal obstruction, which is a result of progression of many diseases. This paper will review the common causes of pyloric stenosis and its non-surgical treatments, mainly endoscopic treatment, in recent years. With the development of endoscopic technology, endoscopic treatment will gradually replace surgical treatment for treatment of pyloric obstruction.

Use of macrolides in mother and child and risk of infantile hypertrophic pyloric stenosis: nationwide cohort study

OBJECTIVE

To assess the association between use of macrolide antibiotics in mothers and infants from pregnancy onset until 120 days after birth and infantile hypertrophic pyloric stenosis (IHPS).

DESIGN

Nationwide register based cohort study.

SETTING

Denmark, 1996-2011.

PARTICIPANTS

999,378 liveborn singletons and linked individual level information on macrolide prescriptions (maternal use during pregnancy, n=30,091; maternal use after birth, n=21,557; use in infants, n=6591), surgery for IHPS, and potential confounders.

MAIN OUTCOME MEASURES

Surgery for IHPS by three categories of macrolide use: in mothers during pregnancy, in mothers after birth, and in infants after birth.

RESULTS

880 infants developed IHPS (0.9 cases per 1000 births). Compared with infants with no use of macrolides, the adjusted rate ratio for IHPS in infants with use of macrolides during days 0 to 13 after birth was 29.8 (95% confidence interval 16.4 to 54.1) and during days 14 to 120 was 3.24 (1.20 to 8.74); the corresponding absolute risk differences were 24.4 (95% confidence interval 13.0 to 44.1) and 0.65 (0.06 to 2.21) cases per 1000 infants exposed to macrolides, respectively. The rate ratio for maternal use of macrolides for days 0 to 13 after birth was 3.49 (1.92 to 6.34) and for days 14 to 120 was 0.70 (0.26 to 1.90); the corresponding absolute risk differences were 2.15 (0.82 to 4.64) and -0.11 (-0.26 to 0.31). The rate ratios for maternal use of macrolides during pregnancy were 1.02 (0.65 to 1.59) for weeks 0 to 27 and 1.77 (0.95 to 3.31) for weeks 28 to birth; the corresponding absolute risk differences were 0.01 (-0.31 to 0.50) and 0.67 (-0.06 to 2.02).

CONCLUSIONS

Treatment of young infants with macrolide antibiotics was strongly associated with IHPS and should therefore only be administered if potential treatment benefits outweigh the risk. Maternal use of macrolides during the first two weeks after birth was also associated with an increased risk of IHPS. A possible association was also found with use during late pregnancy.

Plasma lipids, genetic variants near APOA1, and the risk of infantile hypertrophic pyloric stenosis

IMPORTANCE

Infantile hypertrophic pyloric stenosis (IHPS) is a serious condition in which hypertrophy of the pyloric sphincter muscle layer leads to gastric outlet obstruction. Infantile hypertrophic pyloric stenosis shows strong familial aggregation and heritability, but knowledge about specific genetic risk variants is limited.

OBJECTIVES

To search the genome comprehensively for genetic associations with IHPS and validate findings in 3 independent sample sets.

DESIGN, SETTING, AND PARTICIPANTS

During stage 1, we used reference data from the 1000 Genomes Project for imputation into a genome-wide data set of 1001 Danish surgery-confirmed samples (cases diagnosed 1987-2008) and 2371 disease-free controls. In stage 2, the 5 most significantly associated loci were tested in independent case-control sample sets from Denmark (cases diagnosed 1983-2010), Sweden (cases diagnosed 1958-2011), and the United States (cases diagnosed 1998-2005), with a total of 1663 cases and 2315 controls.

MAIN OUTCOMES AND MEASURES

Association of genetic variation with the presence of infantile hypertrophic pyloric stenosis.

RESULTS

We found a new genome-wide significant locus for IHPS at chromosome 11q23.3. The single-nucleotide polymorphism (SNP) with the lowest P value at the locus, rs12721025 (odds ratio [OR], 1.59; 95% CI, 1.38-1.83; P = 1.9 × 10(-10)), is located 301 bases downstream of the apolipoprotein A-I (APOA1) gene and is correlated (r2 between 0.46 and 0.80) with SNPs previously found to be associated with levels of circulating cholesterol. For these SNPs, the cholesterol-lowering allele consistently was associated with increased risk of IHPS.

CONCLUSIONS AND RELEVANCE

This study identified a new genome-wide significant locus for IHPS. Characteristics of this locus suggest the possibility of an inverse relationship between levels of circulating cholesterol in neonates and IHPS risk, which warrants further investigation.

Tetrahydrobiopterin deficiency induces gastroparesis in newborn mice

Pyloric stenosis, the most common infant gastrointestinal disease, has no known etiology and clinically presents as abnormal gastric emptying with evidence of pyloric muscle hypertrophy. Whether abnormalities in gastric muscle contraction and/or relaxation have a role in this condition is poorly known, but gastroparesis is commonly observed in association with delayed gastric emptying in adults. Therefore, we evaluated the tetrahydrobiopterin (BH4)-deficient newborn mouse model of this disease (hph-1) and hypothesized that their gastric muscle properties are impaired, when compared with wild-type control animals. In vitro studies evaluating the age-dependent gastric fundus muscle contraction and relaxation potential were conducted. Compared with wild-type mice, the hph-1 stomach content/body weight ratio was significantly increased in newborn but not juvenile or adult animals, confirming abnormal gastric emptying. Gastric tissue neuronal nitric oxide synthase (nNOS) protein expression was upregulated in both newborn and adult hph-1 mice, but in the former there was evidence of enzyme uncoupling and higher tissue superoxide generation when compared with same age-matched animals. As opposed to the lack of strain differences in the U46619-induced force, the newborn hph-1 gastric muscle carbachol-induced contraction and nNOS-dependent relaxation were significantly reduced (P < 0.01). These group differences were not present in juvenile or adult mice. Preincubation with BH4 significantly enhanced the newborn hph-1, but not wild-type, gastric muscle contraction. In conclusion, changes compatible with gastroparesis are present in the newborn mouse model of pyloric stenosis. The role of BH4 deficiency and possibly associated gastroparesis in the pathogenesis of infantile pyloric stenosis warrants further investigation.

Infantile hypertrophic pyloric stenosis in twins

Infantile hypertrophic pyloric stenosis (IHPS) is a common surgical cause of vomiting, which requires surgery in infant. There is the complete or partial obstruction of pylorus due to hypertrophy of circular muscle of the pylorus leading gastric outlet obstruction. The occurrence of IHPS in dizygotic twins is rarer and the theory of genetic origin alone does not explain it. Recent literature points to the association of bottle feeding in singletons to be a major aetiological factor for this condition. Here, we present a rare case of dizygotic twins who were bottle-fed and were affected with IHPS. We review the literature and focus on the question of whether this condition in twins supports a genetic or environmental origin of IHPS.