To test the hypothesis that exposure to ambient language in the womb alters phonetic perception shortly after birth. This two-country study aimed to see if neonates demonstrated prenatal learning by how they responded to vowels in a category from their native language and another nonnative language, regardless of how much postnatal experience the infants had.
A counterbalanced experiment was conducted in Sweden (n=40) and the USA (n=40) using Swedish and English vowel sounds. The neonates (mean postnatal age = 33 hrs) controlled audio presentation of either native or nonnative vowels by sucking on a pacifier, with the number of times they sucked their pacifier being used to demonstrate what vowel sounds attracted their attention. The vowels were either the English /i/ or Swedish /y/ in the form of a prototype plus 16 variants of the prototype.
The infants in the native and nonnative groups responded differently. As predicted, the infants responded to the unfamiliar nonnative language with higher mean sucks. They also sucked more to the nonnative prototype. Time since birth (range: 7–75 hours) did not affect the outcome.
The ambient language to which foetuses are exposed in the womb starts to affect their perception of their native language at a phonetic level. This can be measured shortly after birth by differences in responding to familiar vs. unfamiliar vowels.
fetal; language; learning; neonatal; vowels
Parental behavior described as “scaffolding” has been shown to influence outcomes in at-risk children. The purpose of this study was to compare maternal verbal scaffolding in toddlers born preterm and full term.
The scaffolding behavior of mothers of toddlers born preterm and healthy full term was compared during a 5 minute videotaped free play session with standardized toys. We compared two types of scaffolding and their associations with socio-demographic, neonatal medical factors, and cognition.
The mothers of toddlers born full term used more complex scaffolding. Maternal education was associated with complex scaffolding scores for the preterm children only. Specifically, the preterm children who were sicker in the neonatal period, and whose mothers had higher education, used more complex scaffolding. In addition, children born preterm who had less days of ventilation, had higher cognitive scores when their mothers used more complex scaffolding. Similarly, cognitive and scaffolding scores were higher for children born full term.
Our findings highlight early differences in mother-child interactive styles of toddlers born preterm compared to full term. Teaching parents play methods that support early problem solving skills may support a child’s method of exploration and simultaneously their language development.
Cognition; Maternal Education; Maternal Scaffolding; Preterm
To describe the prevalence of paediatric sleep disordered breathing (SDB) symptoms in extremely low gestational age infants and identify neonatal risk factors, including early exposure to hypoxia and hyperoxia.
Patients <28 weeks gestation were monitored with high-resolution pulse oximetry. Hypoxia/hyperoxia variables were defined as percentage time of first 4 weeks of life that SaO2 < 80% or SaO2 > 98%, respectively. Parents completed part of the OSA-18 questionnaire for symptoms of SDB at 18–22 months. Logistic regression was used to test the association between risk factors and sleep symptoms.
Of 182 patients recruited, 138 (76%) completed the questionnaire. The mean gestation was 26 weeks, and mean birth weight 887 grams. Loud snoring (21%) and restless sleep (24%) were the most prevalent symptoms. Female sex was associated with an increased risk of loud snoring (OR, 2.7; CI, 1.13–6.5). Prolonged mechanical ventilation, necrotizing enterocolitis and prolonged caffeine use, however, were inversely correlated with loud snoring. Neither neonatal hypoxia nor hyperoxia were associated with sleep symptoms.
While the prevalence of sleep disordered breathing symptoms is similar to reported rates, we found a sex difference not previously reported. Interestingly, markers for severity of illness show a pattern of being protective against loud snoring.
Snoring; Sleep disordered breathing; Prematurity
Aim Olfactory sensation is highly functional early in human neonatal life, with studies suggesting that odours can influence behaviour and infant–mother bonding. Due to its good spatial properties, blood oxygen level–dependent (BOLD) contrast functional magnetic resonance imaging (fMRI) has the potential to rapidly advance our understanding of the neural activity which underlies the development of olfactory perception in this key period. We aimed to design an ‘olfactometer’ specifically for use with neonatal subjects for fMRI studies of odour perception.
Methods We describe a fully automated and programmable, fMRI compatible system capable of presenting odorant liquids. To prevent contamination of the system and minimize between-subject infective risk, the majority of the olfactometer is constructed from single-use, readily available clinical equipment. The system was used to present the odour of infant formula milk in a validation group of seven neonatal subjects at term equivalent postmenstrual age (median age 40 weeks).
Results A safe, reliable and reproducible pattern of stimulation was delivered leading to well-localized positive BOLD functional responses in the piriform cortex, amygdala, thalamus, insular cortex and cerebellum.
Conclusions The described system is therefore suitable for detailed studies of the ontology of olfactory sensation and perception during early human brain development.
fMRI; Infant; Newborn; Olfactory
The loop diuretics furosemide and bumetanide are commonly used in neonatal intensive care units (NICUs). Furosemide, due to its actions on the ubiquitous NKCC1 co-transporter and its promotion of prostanoid production and release, also has non-diuretic effects on vascular smooth muscle, airways, the ductus arteriosus, and theoretically the gastrointestinal tract. Loop diuretics also affect the central nervous system through the inhibitory neurotransmitter, GABA.
The loop diuretics have a variety of biological effects that are potentially harmful as well as beneficial. Care should be taken with the use of these agents since the range of their effects may be broader than the single action sought by the prescribing physician.
GABA-A receptor; Na-K-2Cl cotransporter; furosemide; bumetanide; ductus arteriosus
Perturbations in dietary and hormonal components of the calciotropic network may be mediated through the influence of calcium homeostasis on resting energy expenditure (REE). We investigated the association of dietary and hormonal factors involved in the regulation of calcium homeostasis with REE in girls.
Thirty-six girls age 7–11 years participated. REE was assessed by indirect calorimetry, and body composition, dietary intake (calcium, vitamins D and K, phosphorus), and serum hormones (PTH, osteocalcin, 25OHD), were evaluated by DXA, 24h recall and serum assay, respectively.
A positive association between vitamin K and REE and an inverse association of PTH with REE (p=0.05) was observed. PTH and REE were positively related in those having normal adiposity (p=0.03) and inversely related in those with excess adiposity (p=0.01). The association of REE with vitamin K intake was evident in lean individuals (p=0.001), but was null in those with excess adiposity.
Decreased calciotropic hormone levels along with increased related nutrient intakes were associated with greater REE, although these relationships differed according to adiposity. The physiologic response to the diet and subsequent energy partitioning needs to be considered in the context of puberty. In particular, regulation and signaling of the calciotropic network during pubertal maturation warrant investigation.
Calcium homeostasis; puberty; diet; adiposity; calciotropic
To test the hypothesis that plasma lipid metabolite levels in premature infants are associated with the development of bronchopulmonary dysplasia (BPD). The studies also tested a secondary hypothesis that plasma lipid metabolite levels were correlated with gestational age.
Infants born less than 32 weeks gestation were enrolled during the first 72 hours of life. Plasma samples were obtained and lipid levels were measured by LC-MS/MS. Clinical data were collected to determine infant outcomes and BPD diagnosis.
Following adjustment for confounders, lipid levels were not associated with BPD; however, levels of specific lipid metabolites were correlated with gestational age.
Immature lipid metabolism pathways in premature infants may contribute to the pathogenesis of BPD and other diseases.
bronchopulmonary dysplasia (BPD); lipids; gestational age; LC-MS/MS
To assess long-term safety and compare neurodevelopmental outcomes in school age children born prematurely who received inhaled nitric oxide or placebo during the first week of life in a randomized, double blind study. Children treated with inhaled nitric oxide had previously been shown to have decreased intraventricular hemorrhage and periventricular leukomalacia as newborns, and decreased cognitive impairment at 2 years1–2.
Follow-up study of medical outcomes, neurodevelopmental assessment and school readiness in 135 of 167 (81%) surviving premature infants seen at 5.7 ± 1.0 years.
Compared to placebo (n=65), iNO-treated children (n=70) demonstrated no difference in growth parameters, school readiness, or need for subsequent hospitalization. However, iNO-treated children were less likely to have multiple chronic morbidities or technology-dependence (p=0.05). iNO-treated children also had less functional disability (p=0.05).
These results demonstrate the long-term safety of iNO in premature infants. Furthermore, iNO treatment may improve health status by decreasing the incidence of severe ongoing morbidities and technology-dependence, and may also decrease the incidence of educational and community functional disability of premature infants at early school age.
clinicaltrials.gov Identifier: NCT00152542
Nitric oxide inhalation; Prematurity; School-age outcome; Safety
To compare the frequency of elevated concentrations of inflammation-related proteins in the blood of infants born before the 28th week of gestation who had documented bacteremia to those who had presumed (antibiotic-treated but culture-negative) bacteremia to those who neither.
The subjects of this study are the 868 infants born at 14 institutions for whom information about protein measurements on at least two of the three protocol days (days 1, 7, and 14) was available and who did not have Bell stage 3 necrotizing enterocolitis or isolated bowel perforation, which were strongly associated with bacteremia in this sample.
Newborns with presumed early (week 1) bacteremia had elevated concentrations of only a few inflammation-related proteins, while those who had presumed late (weeks 2–4) bacteremia did not have any elevations. In contrast, newborns who had documented early bacteremia had a moderately strong signal, while those who had documented late bacteremia had a stronger signal with more protein concentrations elevated on two separate occasions a week apart.
Culture-confirmed early and late bacteremia are accompanied/followed by systemic inflammatory responses not seen with presumed early and late bacteremia.
bacteremia; infant; premature; blood proteins
To characterize postnatal changes in serum insulin-like growth factor-1 (IGF-I) in relation to development of bronchopulmonary dysplasia (BPD) in very preterm infants.
Longitudinal study of 108 infants with mean (SD) gestational age (GA) 27.2 (2.2) weeks. Weekly serum samples of IGF-I were analysed from birth until postmenstrual age (PMA) 36 weeks. Multivariate models were developed to identify independent predictors of BPD.
Postnatal mean IGF-I levels at postnatal day (PND) 3–21 were lower in infants with BPD compared with infants with no BPD (16 vs. 26 μg/L, p < 0.001). Longitudinal postnatal change in IGF-I levels (IGF-I regression coefficient (β)), PNDs 3–21, was lower in infants with BPD compared with infants with no BPD (0.28 vs. 0.97, p = 0.002) and mean IGF-I during PMA 30–33 weeks was lower in infants with BPD as compared with infants without BPD (22 vs. 29 μg/L, p < 0.001). In a binomial multiple regression model, lower GA, male gender and lower mean serum IGF-I levels during PND 3–21 were the most predictive risk factors associated with BPD (r2 = 0.634, p < 0.001).
Lower IGF-I concentrations during the first weeks after very preterm birth are associated with later development of BPD.
Bronchopulmonary dysplasia; Insulin-like growth factor-1; Premature infants
To better understand differences between Bayley Scales 3rd edition (Bayley III) Cognitive Scale and Bayley Scales 2nd edition (Bayley II) Mental Developmental Index (MDI) in 18–22 month old children born term and preterm; and to create a conversion algorithm using Bayley II MDI to calculate Bayley III Cognitive score.
This study included 51 term and 26 preterm children between 18 and 22 months, ages adjusted for prematurity. Children’s scores on Bayley II MDI and Bayley III Cognitive Scale were compared using t-tests. The items from Bayley II MDI were used to calculate a score for the Bayley III Cognitive Scale. ANCOVA was used to create a conversion scale.
Bayley III Cognitive scores were significantly higher than Bayley II MDI scores for term and preterm toddlers combined and separately (p<.0001). A conversion formula to convert Bayley II MDI to a Bayley III Cognitive score was calculated.
Term and preterm children had similarly elevated scores on the Bayley III calculated Cognitive score compared to the previous Bayley II MDI score. The use of a conversion algorithm maybe helpful in studies that used both Bayley editions in order to get comparable outcome measurements within a clinical or research paradigm.
Developmental outcome; cognition development; prematurity
To compare risk-adjusted outcomes at 18–22 months corrected age for extremely low birth weight (ELBW) infants who never received phototherapy (NoPTx) to those who received any phototherapy (PTx) in the NICHD Neonatal Research Network randomized trial of Aggressive vs. Conservative Phototherapy.
Outcomes at 18–22 months corrected age included death, neurodevelopmental impairment (NDI), and Bayley Scales Mental Developmental Index (MDI). Regression models evaluated the independent association of PTx with adverse outcomes controlling for center and other potentially confounding variables.
Of 1972 infants, 216 were NoPTx and 1756 were PTx. For the entire 501–1000 g BW cohort, PTx was not independently associated with death or NDI (OR 0.85, 95% CI 0.60 –1.20), death, or adverse neurodevelopmental endpoints. However, among infants 501–750 g BW, the rate of significant developmental impairment with MDI<50 was significantly higher for NoPTx (29%) than PTx (12%) (p=0.004).
Phototherapy did not appear to be independently associated with death or NDI for the overall ELBW group. Whether PTx increases mortality could not be excluded due to bias from deaths before reaching conservative treatment threshold. The higher rate of MDI<50 in the 501–750g BW NoPTx group is concerning, and consistent with NRN Trial results.
To determine whether extremely low birth weight (ELBW) infants with bilateral compared to unilateral intraventricular hemorrhage (IVH) have worse neurodevelopmental outcomes at 18–22 months.
166 ELBW infants (<1000 g) admitted to a Cincinnati NICU from 1998–2005 with a head ultrasound showing Grade I–IV IVH and neurodevelopmental assessment at 18–22 months corrected age were included. Multivariable linear and logistic regression models were developed to determine the impact of laterality and grade of IVH and other clinical variables to predict scores on the Bayley Scales of Infant Development, Second Edition, Mental Development Index (MDI) and Psychomotor Development Index (PDI) and the combined outcome of neurodevelopmental impairment (NDI).
Infants with bilateral grade IV IVH had lower adjusted mean Bayley scores compared with infants with unilateral grade IV IVH. For grades I, II, and III IVH, bilaterality of IVH was not associated with lower mean Bayley scores. Infants with grade IV IVH had the highest odds of NDI. The probability of NDI increased with sepsis and postnatal steroid use.
ELBW infants with bilateral compared to those with unilateral grade IV IVH had worse neurodevelopmental outcomes. Infants with grades I–III IVH had similar outcomes whether they had unilateral or bilateral IVH.
premature; sepsis; steroids; Bayley; cognitive; motor
To examine risk and protective factors associated with behavioural problems of children and adolescents following prenatal alcohol exposure.
A total of 73 children and adolescents with foetal alcohol spectrum disorders (FASD) were assessed for internalizing, externalizing and total behavioural problems using the Child Behavior Checklist. Linear regression models were used to determine the effects of diagnostic and environmental risk and protective factors on behaviour, while controlling for age, sex and IQ.
Length of time spent in residential care was the most pervasive risk factor associated with internalizing, externalizing and total behavioural problems. A low dysmorphology score was related to more internalizing and total problems.
Children and adolescents prenatally exposed to alcohol faced greater risk of substantive behavioural problems (i) if they were less visibly alcohol affected and (ii) the longer time they had spent in residential care. The results underscore the clinical importance of appropriate services and care for less visibly affected children with FASD and highlight the need to attend to children with FASD being raised in institutions.
Behavioural problems; Foetal alcohol spectrum disorders; Prenatal alcohol; Risk factors
Sex chromosome tetrasomy and pentasomy conditions occur in 1:18 000–1:100 000 male births. While often compared with 47,XXY/Klinefelter syndrome because of shared features including tall stature and hypergonadotropic hypogonadism, 48,XXYY, 48,XXXY and 49,XXXXY syndromes are associated with additional physical findings, congenital malformations, medical problems and psychological features. While the spectrum of cognitive abilities extends much higher than originally described, developmental delays, cognitive impairments and behavioural disorders are common and require strong treatment plans. Future research should focus on genotype–phenotype relationships and the development of evidence-based treatments.
The more complex physical, medical and psychological phenotypes of 48,XXYY, 48,XXXY and 49,XXXXY syndromes make distinction from 47,XXY important; however, all of these conditions share features of hypergonadotropic hypogonadism and the need for increased awareness, biomedical research and the development of evidence-based treatments.
Hypogonadism; Klinefelter syndrome; XXXXY syndrome; XXXY syndrome; XXYY syndrome
To explore the association of serum bilirubin level and breast milk feeding with retinopathy of prematurity (ROP) in preterm infants.
We conducted a case-control study to examine the independent and combined effects of serum bilirubin and breast milk feeding on ROP risk in infants <32 weeks gestation or with birth weight <1500 grams. Cases (66 infants with ROP) were matched with controls (66 infants without ROP) based on factors know to affect ROP risk.
When analyzed using the paired t test, the peak bilirubin levels were lower in ROP cases than in controls (mean 7.2 vs 7.9 mg/dl; P=0.045). Using conditional logistic regression, we found a negative association between highest serum bilirubin level and risk of ROP (OR=0.82 per 1-mg/dl change in bilirubin (P=0.06). There was no significant association between breast milk feeding and risk of ROP.
Bilirubin may help to protect preterm infants against ROP.
bilirubin; breast milk; preterm; retinopathy of prematurity
To explore risk patterns for presumed and definite, early and late neonatal bacteremia.
We studied 1106 ELGANs who survived until postnatal day 28. We defined early definite bacteremia as a positive bacterial culture in the first week and definite late bacteremia as a positive bacterial culture in week 2, 3 or 4. Bacteremia was presumed if antibiotics were given for more than 72 hours despite negative blood cultures.
Risk patterns did not differ much for presumed and definite bacteremia in the first postnatal month. While maternal and pregnancy characteristics were associated with early bacteremia, neonatal co-morbidities, especially NEC, were the main antecedents/correlates of late bacteremia. All four categories of bacteremia were associated with younger gestational age and lower birth weight. Infants with presumed and definite bacteremia had similar distributions of days of ventilation and oxygenation.
Definite and presumed late bacteremia have rather similar risk patterns, while those of early and late bacteremia differ appreciably.
Infant; risk; sepsis
To investigate the relationship between low Apgar score and neonatal mortality in preterm neonates.
Infant birth and death certificate data from the U.S. National Center for Health Statistics for 2001-2002 were analyzed. Primary outcome was 28 day mortality for 690,933 neonates at gestational ages 24-36 weeks. Mortality rates were calculated for each combination of gestational age and five-minute Apgar score. Relative risks of mortality, by high vs. low Apgar score, were calculated for each age.
Distribution of Apgar scores depended on gestational age, the youngest gestational ages having higher proportions of low Apgar scores. Median Apgar score ranged from 6 at 24 weeks, to 9 at 30-36 weeks gestation. The relative risk of death was significantly higher at Apgar scores 0-3 vs. 7-10, including at the youngest gestational ages, ranging from 3.1 (95% confidence interval 2.9, 3.4) at 24 weeks to 18.5 (95% confidence interval 15.7, 21.8) at 28 weeks.
Low Apgar score was associated with increased mortality in premature neonates, including those at 24 to 28 weeks gestational age, and may be a useful tool for clinicians in assessing prognosis and for researchers as a risk prediction variable.
Apgar score; Neonatal mortality; Prematurity
To assess the blood pressure of former preterm and term matched adolescent controls, and identify risk factors associated with blood pressure at 16 years.
Observational cohort study. Secondary analysis of a randomized clinical trial.
Three academic centers participating in the Multicenter Indomethacin IVH Prevention Trial.
296 children born in 1989–1992 with birth weights 600- <1250g who participated in the Multicenter Indomethacin IVH Prevention Trial and 95 term controls were evaluated at 16 years.
Main Outcome Measures
Blood pressure and predictors of blood pressure.
The adjusted mean difference in blood pressure for preterm adolescents was 5.1 mm Hg; p=0.002 for systolic and 2.1 mm Hg; p=0.027 for diastolic blood pressure. Among preterms, the primary predictors of increased systolic blood pressure were weight gain velocity between birth and 36 months (b=8.54, p<.001), preeclampsia (b=5.67, p=0.020), non-white race (b=3.77, p=0.04) and male gender (b=5.09). Predictors of diastolic blood pressure were weight gain velocity between birth and 36 months, (b=4.69, p=0.001, brain injury (b=6.51, p=0.002 and male gender (b=−2.4, p=0.02).
Early programming secondary to increased early weight gain velocity, intrauterine stress and neonatal brain injury may all contribute to risk of increased blood pressure among former preterm adolescents.
brain injury; hypertension; preterm; weight gain velocity
Retinopathy of prematurity; inflammation; low gestational age
To assess the influence of clinical status on the association between total plasma bilirubin and unbound bilirubin on death or adverse neurodevelopmental outcomes at 18–22 months corrected age in extremely low birth weight infants.
Total plasma biirubin and unbound biirubin were measured in 1,101 extremely low birth weight infants at 5±1 day of age. Clinical criteria were used to classify infants as clinically stable or unstable. Survivors were examined at 18–22 months corrected age by certified examiners. Outcome variables were death or neurodevelopmental impairment, death or cerebral palsy, death or hearing loss, and death prior to follow-up. For all outcomes, the interaction between bilirubin variables and clinical status was assessed in logistic regression analyses adjusted for multiple risk factors.
Regardless of clinical status, an increasing level of unbound bilirubin was associated with higher rates of death or neurodevelopmental impairment, death or cerebral palsy, death or hearing loss and death before follow-up. Total plasma bilirubin values were directly associated with death or neurodevelopmental impairment, death or cerebral palsy, death or hearing loss, and death before follow-up in unstable infants, but not in stable infants. An inverse association between total plasma bilirubin and death or cerebral palsy was found in stable infants.
In extremely low birth weight infants, clinical status at 5 days of age affects the association between total plasma and unbound bilirubin and death or adverse neurodevelopmental outcomes at 18–22 months of corrected age. An increasing level of UB is associated a higher risk of death or adverse neurodevelopmental outcomes regardless of clinical status. Increasing levels of total plasma bilirubin are directly associated with increasing risk of death or adverse neurodevelopmental outcomes in unstable, but not in stable infants.
Plasma bilirubin; unbound bilirubin; Extremely low birth weight infants; Neurodevelopmental outcomes
Rasch S, Sangild PT, Gregersen H., Schmidt M., Omari T, Lau C. The Preterm Piglet – an Animal Model for the Oesophageal Maturation in Preterm Neonates. Acta Paediatr ...... Stockholm. ISSN ......
Preterm infants have difficulty attaining independent oral feeding. This can ensue from inadequate sucking, swallowing, and/or respiration. In impeding bolus transport, immature oesophageal motility may also be a cause. As studies on the development of oesophageal motility are invasive in preterm infants, the preterm piglet was investigated as a potential research model.
Oesophageal motility (EM) of term (n=6) and preterm (n=15) piglets were monitored by manometry for 10 min immediately following bottle feeding on days 1-2 and 3-4 of life.
Piglets’ oral feeding performance and EM were similar to those of their human counterparts. Term piglets readily completed their feeding whereas their preterm counterparts did not. They also presented with greater peristaltic activity and propagating velocity. Peristaltic activity remained unchanged over time in preterm piglets, but an increase in synchronous and decrease in incomplete motor activity were noted. Preterm piglets that developed symptoms analogous to necrotizing enterocolitis (NEC) demonstrated uncharacteristic oesophageal activity.
Immature EM may cause oral feeding difficulties. NEC-like symptoms may adversely affect EM. The piglet is a valid research model for studying human infant oral feeding and oesophageal development.
oral feeding; prematurity; oesophageal motility
Early working memory is emerging as an important indicator of developmental outcome predicting later cognitive, behavioural and academic competencies. The current study compared early working memory in a sample of toddlers (18–22 months) born very low birth weight (VLBW; n = 40) and full term (n = 51) and the relationship between early working memory, mental developmental index (MDI), and maternal communication in both samples.
Early working memory, measured by object permanence; Bayley mental developmental index; and maternal communication, coded during mother-toddler play interaction, were examined in 39 toddlers born VLBW and 41 toddlers born full term.
Toddlers born VLBW were found to be 6.4 times less likely to demonstrate attainment of object permanence than were toddlers born full term, adjusting for age at testing. MDI and maternal communication were found to be positively associated with attainment of object permanence in the VLBW group only.
The difference found in the early working memory performance of toddlers born VLBW, compared with those born full term, emphasizes the importance of assessing early working memory in at-risk populations, while the maternal communication finding highlights potential targets of intervention for improving working memory in toddlers born VLBW.
Early working memory; Maternal communication; Object permanence; Very low birth weight
To explore associations between acute otitis media in early childhood and prenatal and postnatal tobacco smoke exposure.
Subjects were 32,077 children born 2000 – 2005 in the Norwegian Mother and Child Study with questionnaire data on tobacco smoke exposure and acute otitis media up to 18 months of age. Multivariate regression models were used to obtain adjusted relative risks for acute otitis media.
Acute otitis media was slightly more common in children exposed to parental smoking. The incidence from 0–6 months was 4.7% in unexposed children, and 6.0% in children exposed both pre-and postnatally. After adjusting for postnatal exposure and covariates, the relative risk for acute otitis media 0–6 months when exposed to maternal smoking in pregnancy was 1.34, 95% confidence interval: 1.06–1.69. Maternal smoking in pregnancy was associated with acute otitis media up to 12 months of age. Compared to non-exposed children, there was a slightly increased risk of recurrent acute otitis media for children exposed both pre- and postnatally with a relative risk of 1.24, 95% confidence interval: 1.01–1.52,.
Even in a cohort with relatively low exposure levels of parental smoking, maternal smoking in pregnancy was associated with an increased risk of acute otitis media in early childhood.
Acute otitis media; Smoking; Pregnancy; Norway; Cohort studies