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

Maternal factors in the origin of infantile hypertrophic pyloric stenosis: A population-based case-control study

In most patients affected by isolated infantile hypertrophic pyloric stenosis (IHPS) the etiology is largely unknown. Thus, the aim of this study was to estimate possible maternal risk factors in the origin of IHPS. The study samples included 241 cases with IHPS, 357 matched controls and 38,151 population controls without any defect in the population-based large dataset of the Hungarian Case-Control Surveillance of Congenital Abnormalities, 1980-1996. Exposures that had been medically recorded in prenatal maternity logbooks during the critical period of IHPS were evaluated separately. The findings of this case-control study suggested that--beyond the well-known robust male excess (85.5%)--maternal hyperthyroidism (OR with 95% CI: 4.17, 1.53-11.38) and oral nalidixic acid treatment (OR with 95% CI: 6.53, 3.03-14.06) associated with a higher risk for IHPS in their children. In conclusion, our findings suggest that cases with IHPS had mothers with a higher proportion of hyperthyroidism and nalidixic acid treatment during pregnancy.

Antibiotics and Breastfeeding

During the breastfeeding period, bacterial infections can occur in the nursing mother, requiring the use of antibiotics. A lack of accurate information may lead health care professionals and mothers to suspend breastfeeding, which may be unnecessary. This article provides information on the main antibiotics that are appropriate for clinical use and the interference of these antibiotics with the infant to support medical decisions regarding the discontinuation of breastfeeding. We aim to provide information on the pharmacokinetic factors that interfere with the passage of antibiotics into breast milk and the toxicological implications of absorption by the infant. Publications related to the 20 most frequently employed antibiotics and their transfer into breast milk were evaluated. The results demonstrate that most antibiotics in clinical use are considered suitable during breastfeeding; however, the pharmacokinetic profile of each drug must be observed to ensure the resolution of the maternal infection and the safety of the infant.

Pharmacokinetics of Transfer of Azithromycin into the Breast Milk of African Mothers

Azithromycin (AZI) is used for its antibiotic and antimalarial properties in pregnancy. Reported estimates of AZI breast milk transfer, based on concentrations in mostly single samples from small numbers of women, have suggested that infant intake is safe. To better characterize infant intake and the associated potential benefits and risks, AZI was measured by liquid chromatography-mass spectrometry in four breast milk samples taken over 28 days postpartum from each of 20 Gambian women given 2 g AZI during labor. A population pharmacokinetic model utilizing published parameters for AZI disposition in pregnancy, the present breast milk concentrations, and increasing/decreasing sigmoid maximum-effect (Emax) functions adequately described temporal changes in the milk/plasma ratio. The median estimated absolute and relative cumulative infant doses were 4.5 mg/kg of body weight (95% prediction interval, 0.6 to 7.0 mg/kg) and 15.7% (95% prediction interval, 2.0 to 27.8%) of the maternal dose, respectively; the latter exceeded the recommended 10% safety limit. Although some infants with bacterial infections may benefit from AZI in breast milk, there is a risk of hypertrophic pyloric stenosis with a worst-case number needed to harm of 60 based on the present and available epidemiologic data. (This study has been registered at ClinicalTrials.gov under registration no. NCT01800942.).

Gastro-oesophageal reflux in young babies: who should be treated?

Recent guidelines focus on a non-interventionist approach to management of gastro-oesophageal reflux in infancy and emphasise the importance of explanation, reassurance and simple measures such as attention to feeding. Relying on clinical history alone leads to over diagnosis of disease, and widely used medications are often ineffective for symptom relief and carry significant risk of harm. The association between vomiting in infancy and other problems such as crying and poor feeding should not be interpreted as implying causality. When there are strong pointers to underlying gastro-oesophageal reflux disease, invasive investigations are required in order to formulate appropriate intervention.

Environmental pesticides increase the risk of developing hypertrophic pyloric stenosis

BACKGROUND

Hypertrophic pyloric stenosis (HPS) is a condition noted within the first several weeks of life that results in hypertrophy of the pyloric muscle between the stomach and duodenum. The etiology has not been elucidated but genetic and environmental influences are suspected. We hypothesized that agricultural pesticides would be associated with an increased incidence of pyloric stenosis.

STUDY DESIGN

Data from infants with HPS were obtained from the Indiana Birth Defects Registry (IBDR) for all counties in Indiana from 2005 to 2009. Data from all live births were obtained from the Indiana State Health Department (ISHD). Maternal demographics and clinical characteristics of infants were abstracted. The US Geological Survey (USGS) provided estimated use of agricultural pesticides (EPEST), and these values were correlated with HPS incidence. Univariate and multivariate logistical regression models were used to assess the association between HPS risk and pesticide use.

RESULTS

A total of 442,329 newborns were studied with 1313 HPS cases recorded. The incidence of HPS was 30/10,000 live births. HPS incidence was correlated with total county pesticide use, as well as subcategories of pesticides (fungicides, fumigants, insecticides, herbicides). Indiana counties were then divided into low, moderate and high pesticide use (mean±standard deviation: 127,722±73,374, 308,401±36,915, and 482,008±97,260pounds of pesticides). Incidence of HPS was 26, 29, and 36 cases per 10,000 in low, moderate and high pesticide-use counties respectively. Subset analysis showed that the positive association between HPS and county pesticide use was more likely for male infants from mothers who were white, aged 20-35 years, had education at high school or lower, and smoked (p<0.05).

CONCLUSION

Pesticide use correlated significantly with incidence of HPS. Positive correlations between HPS risk and pesticide use were found for most risk factors. Further studies will be needed to verify our findings and further delineate the nature of this correlation.

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.

Sulphadoxine-pyrimethamine plus azithromycin for the prevention of low birthweight in Papua New Guinea: a randomised controlled trial

BACKGROUND

Intermittent preventive treatment in pregnancy has not been evaluated outside of Africa. Low birthweight (LBW, <2,500 g) is common in Papua New Guinea (PNG) and contributing factors include malaria and reproductive tract infections.

METHODS

From November 2009 to February 2013, we conducted a parallel group, randomised controlled trial in pregnant women (≤ 26 gestational weeks) in PNG. Sulphadoxine-pyrimethamine (1,500/75 mg) plus azithromycin (1 g twice daily for 2 days) (SPAZ) monthly from second trimester (intervention) was compared against sulphadoxine-pyrimethamine and chloroquine (450 to 600 mg, daily for three days) (SPCQ) given once, followed by SPCQ placebo (control). Women were assigned to treatment (1:1) using a randomisation sequence with block sizes of 32. Participants were blinded to assignments. The primary outcome was LBW. Analysis was by intention-to-treat.

RESULTS

Of 2,793 women randomised, 2,021 (72.4%) were included in the primary outcome analysis (SPCQ: 1,008; SPAZ: 1,013). The prevalence of LBW was 15.1% (305/2,021). SPAZ reduced LBW (risk ratio [RR]: 0.74, 95% CI: 0.60-0.91, P = 0.005; absolute risk reduction (ARR): 4.5%, 95% CI: 1.4-7.6; number needed to treat: 22), and preterm delivery (0.62, 95% CI: 0.43-0.89, P = 0.010), and increased mean birthweight (41.9 g, 95% CI: 0.2-83.6, P = 0.049). SPAZ reduced maternal parasitaemia (RR: 0.57, 95% CI: 0.35-0.95, P = 0.029) and active placental malaria (0.68, 95% CI: 0.47-0.98, P = 0.037), and reduced carriage of gonorrhoea (0.66, 95% CI: 0.44-0.99, P = 0.041) at second visit. There were no treatment-related serious adverse events (SAEs), and the number of SAEs (intervention 13.1% [181/1,378], control 12.7% [174/1,374], P = 0.712) and AEs (intervention 10.5% [144/1,378], control 10.8% [149/1,374], P = 0.737) was similar. A major limitation of the study was the high loss to follow-up for birthweight.

CONCLUSIONS

SPAZ was efficacious and safe in reducing LBW, possibly acting through multiple mechanisms including the effect on malaria and on sexually transmitted infections. The efficacy of SPAZ in the presence of resistant parasites and the contribution of AZ to bacterial antibiotic resistance require further study. The ability of SPAZ to improve pregnancy outcomes warrants further evaluation.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01136850 (06 April 2010).

Azithromycin and other macrolides for prevention of bronchopulmonary dysplasia: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

Ureaplasma spp. infection has been associated with bronchopulmonary dysplasia (BPD) in preterm infants. Macrolides have been used for the treatment of Ureaplasma spp. infection, with an intention to prevent BPD. The objective of this meta-analysis is to evaluate the use of macrolides in the prevention of BPD in preterm infants.

METHODS

We searched MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials, abstracts of the major pediatric society meetings and bibliographies of retrieved articles. We included randomized controlled trials assessing the effects of macrolides therapy on BPD in preterm infants. A random/fixed-effect model was used to synthesize predefined outcomes.

RESULTS

Six studies involving 469 preterm infants were eligible for the analysis. Macrolides when used prophylactically (4 studies) did not show significant reduction in BPD (risk ratio, RR, 0.88, 95% confidence interval, CI, 0.75-1.03), death (RR 0.89, 95% CI 0.79-1.01) or in the composite outcome of BPD/death. Similarly, there was no significant reduction in BPD (RR 0.64, 95% CI 0.31-1.31) or the composite outcome of BPD/death (RR 0.41, 95% CI 0.05-3.13), when macrolides were used in Ureaplasma-positive infants. However, prophylactic azithromycin therapy (3 studies) was associated with significant reduction in BPD (RR 0.83, 95% CI 0.71-0.97; number needed to treat, NNT, 10) and composite outcome of BPD/death (RR 0.86, 95% CI 0.77-0.97; NNT 10).

CONCLUSION

This meta-analysis demonstrates prophylactic azithromycin therapy was associated with statistically significant reduction in BPD and the composite outcome of BPD/death in preterm infants. However, given the limited information on pharmacokinetics and potential harmful effects, further studies should be done before routine use of azithromycin in the neonatal population.