Trends in the prevalence of breastfeeding up to 6 months of age using structured data from routine child healthcare visits.

AIM: The Norwegian Action Plan for a Healthier Diet (2017-2021) set the target that 25% of infants should be exclusively breastfed for 6 months by 2022. Our aim was to determine trends in the prevalence and duration of breastfeeding in the municipality of Bergen. METHODS: Data on breastfeeding status in 2010-2018 were extracted from a standardised electronic medical record kept by public child health centres and recorded as exclusive, partial or none, at 6 weeks and 6 months of age. RESULTS: We found that 28,503 and 26,735 infants attended the 6-week and 6-month consultations, respectively. The prevalence of any breastfeeding was 92.0% at 6 weeks and 78.0% at 6 months with no trend over time between 2010 and 2018. The prevalence of exclusive breastfeeding at 6 weeks was 73.9% and stable over time, but it declined at 6 months, from 28.1% in 2010 to 11.1% in 2014 and remained stable thereafter. CONCLUSION: During 2010-2018, the prevalence of any and exclusive breastfeeding at 6 weeks and any breastfeeding at 6 months was stable. Exclusive breastfeeding at 6 months declined halfway through the study period, to a stable, but low, prevalence of 11.1% by 2014.

Tracking of lung function from 10 to 35 years after being born extremely preterm or with extremely low birth weight.

BACKGROUND: Lifelong pulmonary consequences of being born extremely preterm or with extremely low birth weight remain unknown. We aimed to describe lung function trajectories from 10 to 35 years of age for individuals born extremely preterm, and address potential cohort effects over a period that encompassed major changes in perinatal care. METHODS: We performed repeated spirometry in three population-based cohorts born at gestational age ≤28 weeks or with birth weight ≤1000 g during 1982-85, 1991-92 and 1999-2000, referred to as extremely preterm-born, and in term-born controls matched for age and gender. Examinations were performed at 10, 18, 25 and 35 years. Longitudinal data were analysed using mixed models regression, with the extremely preterm-born stratified by bronchopulmonary dysplasia (BPD). RESULTS: We recruited 148/174 (85%) eligible extremely preterm-born and 138 term-born. Compared with term-born, the extremely preterm-born had lower z-scores for forced expiratory volume in 1 s (FEV1) at most assessments, the main exceptions were in the groups without BPD in the two youngest cohorts. FEV1 trajectories were largely parallel for the extremely preterm- and term-born, also during the period 25-35 years that includes the onset of the age-related decline in lung function. Extremely preterm-born had lower peak lung function than term-born, but z-FEV1 values improved for each consecutive decade of birth (p=0.009). More extremely preterm-than term-born fulfilled the spirometry criteria for chronic obstructive pulmonary disease, 44/148 (30%) vs 7/138 (5%), p<0.001. CONCLUSIONS: Lung function after extremely preterm birth tracked in parallel, but significantly below the trajectories of term-born from 10 to 35 years, including the incipient age-related decline from 25 to 35 years. The deficits versus term-born decreased with each decade of birth from 1980 to 2000.

Modifiable and non-modifiable risk factors for obstetric anal sphincter injury in a Norwegian Region: a case-control study.

BACKGROUND: Obstetric anal sphincter injury (OASI) is a common and severe complication of vaginal delivery and may have short- and long-term consequences, including anal incontinence, sexual dysfunction and reduced quality of life. The rate of OASI varies substantially between studies and national birth statistics, and a recent meta-analysis concluded that there is a need to identify unrecognized risk factors. Our aim was therefore to explore both potential modifiable and non-modifiable risk factors for OASI. METHODS: We performed a case-control study in a single center maternity clinic in South-Eastern Norway. Data were extracted retrospectively from an institutional birth registry. The main outcome measure was the occurrence of the woman's first-time 3rd or 4th degree perineal lesion (OASI) following singleton vaginal birth after 30 weeks' gestation. For each woman with OASI the first subsequent vaginal singleton delivery matched for parity was elected as control. The study population included 421 women with OASI and 421 matched controls who gave birth during 1990-2002. Potential risk factors for OASI were assessed by conditional logistic regression analyses. RESULTS: The mean incidence of OASI was 3.4% of vaginal deliveries, but it increased from 1.9% to 5.8% during the study period. In the final multivariate regression model, higher maternal age and birthweight for primiparous women, and higher birthweight for the multiparous women, were the only non-modifiable variables associated with OASI. Amniotomy was the strongest modifiable risk factor for OASI in both primi- (odds ratio [OR] 4.84; 95% confidence interval [CI] 2.60-9.02) and multiparous (OR 3.76; 95% CI 1.45-9.76) women, followed by augmentation with oxytocin (primiparous: OR 1.63; 95% CI 1.08-2.46, multiparous: OR 3.70; 95% CI 1.79-7.67). Vacuum extraction and forceps delivery were only significant risk factors in primiparous women (vacuum: OR 1.91; 95% CI 1.03-3.57, forceps: OR 2.37; 95% CI 1.14-4.92), and episiotomy in multiparous women (OR 2.64; 95% CI 1.36-5.14). CONCLUSIONS: Amniotomy may be an unrecognized independent modifiable risk factor for OASI and should be further investigated for its potential role in preventive strategies.

A family-oriented intervention programme to curtail obesity from five years of age had no effect over no intervention.

AIM: To examine the effect of a family-oriented multidisciplinary intervention programme to curtail weight increase in young children with obesity. METHODS: Children who weighed more than one kilogram above the 97th percentile for height at the preschool assessment in Oppland County, Norway, were identified. Parents residing in one part of the county were invited to participate in a group-based three-year intervention programme while the rest had no interventions. Body mass index (BMI) and family characteristics at entry and measurements at birth were explanatory variables, and change in BMI standard deviation score (SDS) the outcome measure. For the intervention group, outcome was also related to skinfold thicknesses, waist-to-height ratio and physical ability. RESULTS: The programme was completed by 31 families in the intervention and 33 in the control group. At entry, the respective median (interquartile) age was 5.83 (0.36) and 5.74 (0.66) years, and the BMI SDS 2.35 (1.06) and 1.95 (0.49), P = .012. The median decrease in BMI SDS was 0.19 in both groups. The decline increased with increasing BMI SDS at entry, but irrespective of group. Social or behavioural factor or other anthropometric measures were not associated with outcome. CONCLUSION: The intervention programme had no effect on BMI SDS.

No significant associations between breastfeeding practices and overweight in 8-year-old children.

AIM: The aim was to examine if breastfeeding practices were associated with body mass index (BMI) and risk of overweight or obesity in third grade (8 years) of elementary school. METHODS: In a regional cohort, we related BMI z-scores and presence of overweight or obesity at 8 years of age with ever being breastfed and with duration of exclusive and partial breastfeeding after adjusting for potential confounders. Parents completed questionnaires on breastfeeding and sociodemographic and lifestyle factors at school entry, and public health nurses measured height and weight. For non-participants, the nurses anonymously reported these measurements together with sex and age. RESULTS: 90% of participants had been breastfed. In adjusted analyses, BMI z-scores were not significantly related to whether or not the child had been breastfed (P = .64), or to the duration of exclusive (P = .80) or partial breastfeeding (P = .94). Logistic regression also showed no significant association between breastfeeding measures and overweight or obesity. CONCLUSION: This study on 8-year-old Norwegian children did not support a commonly held notion that breastfeeding reduces the risk of overweight or obesity.

Sex-related change in BMI of 15- to 16-year-old Norwegian girls in cross-sectional studies in 2002 and 2017.

BACKGROUND: The prevalence of overweight and obesity (OWOB) has stabilized in some countries, but a portion of children with high body mass index (BMI) may have become heavier. This study aimed to describe the distributions of BMI and the point prevalence of OWOB in Norwegian adolescents in 2002 and 2017. METHODS: A cross-sectional study involving 15- to 16-year-old adolescents in Oppland, Norway, was undertaken in 2002 and 2017. We calculated their BMI, BMI z-scores (BMIz), and the prevalence of OWOB. RESULTS: The mean BMI increased from 20.7 to 21.4 (p < 0.001) for girls but remained unchanged at 21.5 vs 21.4 (p = 0.80) for boys. The prevalence of OWOB increased from 9 to 14% among girls (difference 5, 95% CI: 2, 8) and from 17 to 20% among boys (difference 3, 95% CI: - 1, 6%). The BMI density plots revealed similar shapes at both time points for both sexes, but the distribution for girls shifted to the right from 2002 to 2017. CONCLUSION: Contrary to previous knowledge, we found that the increase in OWOB presented a uniform shift in the entire BMI distribution for 15-16-year-old Norwegian girls and was not due to a larger shift in a specific subpopulation in the upper percentiles.

Serum concentrations of C-reactive protein in healthy term-born Norwegian infants 48-72 hours after birth.

AIM: To determine serum C-reactive protein (CRP) concentrations in healthy term-born infants shortly after birth. METHODS: We sampled blood from 182 infants along with the routine neonatal screening programme at 48-72 hours of age from consecutively recruited healthy infants without signs of infection and a gestational age (GA) of at least 37 weeks. The blood was stored at minus 20°C until analysis in one assay after the end of the study. RESULTS: The CRP levels were positively skewed. The median concentration was 5.0 mg/L, 48.9% of the neonates had values <5.0 mg/L, 19.8% ≥10.0 mg/L, 7.1% ≥20.0 mg/L and 1.1% (2 neonates) >30 mg/L. The CRP level was positively related to GA and duration of labour, slightly higher in boys than girls and after vaginal compared to Caesarean delivery. CONCLUSION: In healthy neonates born at term, the CRP concentrations did not vary substantially with various common perinatal clinical conditions, and levels above 30 mg/L were uncommon at two to three days of age.

Single-family room design in the neonatal intensive care unit did not improve growth.

AIM: The aim was to compare growth in very premature infants cared for in a single-family room (SFR) and an open-bay (OB) unit. We recorded duration of parental presence and skin-to-skin contact as proxies for parental involvement in care of their infants. METHODS: We consecutively included infants with gestational ages 28 + 0 through 32 + 0 weeks at two hospitals in Norway, one SFR unit (n = 35) and one OB unit (n = 42). Weight, length, and head circumference were followed from birth to four months after term date. Both units adhered to the same nutritional protocol and methods of recording events. RESULTS: The SFR mothers spent a mean (standard deviation) of 111 (38) hours and the OB mothers 33 (13) hours with their infants during the first week and 21 (5) versus 7 (3) hours per day later. The respective duration of skin-to-skin care was 21 (10) versus 12 (8) hours during the first week and 4.2 (2) versus 3.0 (2) hours per day later. The differences were similar, but less pronounced for the fathers. The growth trajectories did not differ between the groups. CONCLUSION: SFR care was associated with more parental involvement, but not with better growth.

Respiratory morbidity through the first decade of life in a national cohort of children born extremely preterm.

BACKGROUND: Advances in perinatal care have markedly increased the prospects of survival for infants born extremely preterm (EP). The aim of this study was to investigate hospitalisation rates and respiratory morbidity from five to 11 years of age in a prospective national cohort of EP children born in the surfactant era. METHODS: This was a national prospective cohort study of all children born in Norway during 1999 and 2000 with gestational age (GA) < 28 weeks or birth weight < 1000 grams, and of individually matched term-born controls recruited for a regional subsample. Data on hospital admissions, respiratory symptoms, and use of asthma medication was obtained by parental questionnaires at 11 years of age. RESULTS: Questionnaires were returned for 232/372 (62%) EP-born and 57/61 (93%) regional term-born controls. Throughout the study period, 67 (29%) EP-born and seven (13%) term-born controls were admitted to hospital (odds ratio (OR) 2.90, 95% confidence interval (CI): 1.25, 6.72). Admissions were mainly due to surgical procedures, with only 12% due to respiratory causes, and were not influenced by neonatal bronchopulmonary dysplasia (BPD) or low GA(≤ 25 weeks). Respiratory symptoms, asthma and use of asthma medication tended to be more common for EP-born, significantly so for medication use and wheeze on exercise. Neonatal BPD was a risk factor for medication use, but not for current wheeze. In multivariate regression models, home oxygen after discharge (OR 4.84, 95% CI: 1.38, 17.06) and parental asthma (OR 4.38, 95% CI: 1.69, 11.38) predicted current asthma, but neither BPD nor low GA were associated with respiratory symptoms at 11 years of age. CONCLUSIONS: Hospitalisation rates five to 11 years after EP birth were low, but twice those of term-born controls, and unrelated to neonatal BPD and low GA. Respiratory causes were rare. Respiratory complaints were more common in children born EP, but the burden of symptoms had declined since early childhood.

Increased Bronchial Hyperresponsiveness and Higher Asymmetric Dimethylarginine Levels after Fetal Growth Restriction.

Bronchial hyperresponsiveness (BHR), a feature of asthma, is observed in preterm-born children and has been linked to intrauterine growth restriction. BHR is mediated via airway smooth muscle tone and is modulated by the autonomic nervous system, nitric oxide, and airway inflammation. Interactions among these factors are insufficiently understood. Methacholine-induced BHR (Met-BHR), fractional exhaled NO, and systemic soluble markers of nitric oxide metabolism and inflammation were determined in a population-based sample of 57 eleven-year-old children born extremely preterm (gestational age [GA] < 28 wk) or with extremely low birth weight (<1,000 g), and in a matched normal-birth weight term-born control group (n = 54). Bronchopulmonary dysplasia (BPD) was defined as the need for oxygen treatment at a GA of 36 weeks. In preterm-born children, birth weight below the 10th percentile for GA was associated with increased Met-BHR and higher plasma levels of asymmetric dimethylarginine (ADMA), with an increased odds ratio for being in the upper tertile of Met-BHR (11.8; 95% confidence interval, 3.3-42.4) and of ADMA (5.2; 95% confidence interval, 1.3-20.3). Met-BHR was correlated to ADMA level (r = 0.27, P = 0.007). There were no significant differences in Met-BHR, fractional exhaled NO, or z-FEV1 according to BPD status. No associations with systemic soluble markers of inflammation were observed for Met-BHR, birth, or BPD status. Intrauterine growth restriction in preterm-born children was associated with substantially increased Met-BHR and higher ADMA levels, suggesting altered nitric oxide regulation. These findings contribute to the understanding of the consequences from an adverse fetal environment; they should also be tested in term-born children.

Children born extremely preterm had different sleeping habits at 11 years of age and more childhood sleep problems than term-born children.

AIM: This study explored whether extremely preterm (EPT) children had different sleep characteristics in childhood than children born at term and how neurodevelopmental disabilities (NDD) affected sleep in children born EPT. METHODS: A Norwegian national cohort of 231 children born EPT from 1999 to 2000 and separate study data on 556 children born at term in 2001 were compared. Parental questionnaires mapped the children's current sleep habits at 11 years of age, namely the prevalence of sleep problems throughout childhood until this age and five categories of sleep problems. In addition, the EPT children were clinically assessed at five years of age. RESULTS: The EPT children had different sleep habits than the controls, for example they went to bed earlier. EPT children had a higher prevalence of sleep problems than the controls throughout childhood (26% versus 14%, p < 0.001) and this was also higher for the 93 EPT children with no NDD (20%) than for the controls (14%) and increased with increasing NDD to 67% (p = 0.015) for the six children with severe NDD. CONCLUSION: EPT children had different sleep habits to term-born controls at 11 years of age, including those with no NDD. The prevalence of sleep problems increased with increasing NDD.

Is consumption of sugar-sweetened soft drinks during pregnancy associated with birth weight?

In Norway, there were parallel increases and subsequent decreases in birth weight (BW) and consumption of sugar-sweetened carbonated soft drinks (SSC) during the period 1990-2010, and by an ecological approach, we have suggested that the relationship was causal. The objective of this study was to examine if such a relationship was present in a prospectively followed cohort of pregnant women. The study population included 62,494 term singleton mother-infant dyads in the Norwegian Mother and Child Cohort Study (MoBa), a national prospective cohort study in Norway from 1999 to 2008. The association between SSC consumption and BW was assessed using multiple regression analyses with adjustment for potential confounders. Each 100 ml intake of SSC was associated with a 7.8 g (95% confidence interval [CI]: -10.3 to -5.3) decrease in BW, a decreased risk of BW > 4,500 g (odds ratio [OR]: 0.94, 95% CI: 0.90 to 0.97) and a near significantly increased risk of BW < 2,500 g (OR: 1.05, 95% CI: 0.99 to 1.10). The negative association with SSC consumption was aggravated by smoking, lack of exercise, and obesity. For mothers with gestational diabetes mellitus, we observed an increased risk of BW > 4,500 g (OR: 1.18, 95% CI: 1.00 to 1.39) and a trend towards significant increase in mean BW (25.1 g, 95% CI: -2.0 to 52.2) per 100 ml SSC. Our findings suggest that increasing consumption of rapidly absorbed sugar from SSC had opposite associations with BW in normal pregnancies and pregnancies complicated by gestational diabetes mellitus.

Motor development related to duration of exclusive breastfeeding, B vitamin status and B12 supplementation in infants with a birth weight between 2000-3000 g, results from a randomized intervention trial.

BACKGROUND: Exclusive breastfeeding for 6 months is assumed to ensure adequate micronutrients for term infants. Our objective was to investigate the effects of prolonged breastfeeding on B vitamin status and neurodevelopment in 80 infants with subnormal birth weights (2000-3000 g) and examine if cobalamin supplementation may benefit motor function in infants who developed biochemical signs of impaired cobalamin function (total homocysteine (tHcy) > 6.5 µmol/L) at 6 months. METHODS: Levels of cobalamin, folate, riboflavin and pyridoxal 5´-phosphate, and the metabolic markers tHcy and methylmalonic acid (MMA), were determined at 6 weeks, 4 and 6 months (n = 80/68/66). Neurodevelopment was assessed with the Alberta Infants Motor Scale (AIMS) and the parental questionnaire Ages and Stages (ASQ) at 6 months. At 6 months, 32 of 36 infants with tHcy > 6.5 µmol/L were enrolled in a double blind randomized controlled trial to receive 400 µg hydroxycobalamin intramuscularly (n = 16) or sham injection (n = 16). Biochemical status and neurodevelopment were evaluated after one month. RESULTS: Except for folate, infants who were exclusively breastfed for >1 month had lower B vitamin levels at all assessments and higher tHcy and MMA levels at 4 and 6 months. At 6 months, these infants had lower AIMS scores (p = 0.03) and ASQ gross motor scores (p = 0.01). Compared to the placebo group, cobalamin treatment resulted in a decrease in plasma tHcy (p < 0.001) and MMA (p = 0.001) levels and a larger increase in AIMS (p = 0.02) and ASQ gross motor scores (p = 0.03). CONCLUSIONS: The findings suggest that prolonged exclusive breastfeeding may not provide sufficient B vitamins for small infants, and that this may have a negative effect on early gross motor development. In infants with mild cobalamin deficiency at 6 months, cobalamin treatment significantly improvement cobalamin status and motor function, suggesting that the observed impairment in motor function associated with long-term exclusive breastfeeding, may be due to cobalamin deficiency. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, number NCT01201005.

Respiratory illness contributed significantly to morbidity in children born extremely premature or with extremely low birthweights in 1999-2000.

AIM: This study investigated respiratory morbidity and risk factors during the first five years of life after extremely preterm birth. METHODS: Paediatric assessments and parental questionnaires were obtained at two and five years of age in this national prospective cohort of 372 Norwegian children born during 1999-2000 at a gestational age of <28 weeks or birthweight <1,000 grams. RESULTS: Paediatric assessments were obtained for 100% and 82% of the children at two and five years of age and completed questionnaires for 71% and 76%, respectively. Total readmission rates decreased from 49 to 14% at one to five years, and readmissions for respiratory causes fell from 31 to 3%. Bronchopulmonary dysplasia (BPD) or gestational age was not associated with readmissions for respiratory causes in multiple logistic regression models. However, both BPD and gestational age ≤ 25 weeks was associated with wheezing during the first year and the use of asthma medication during the first two years. BPD was associated with asthma medication between three and five years but not significantly at five years. CONCLUSION: Respiratory morbidity decreased during the first five years of life but was still more common than expected. It was unrelated to BPD and gestational age at five years of age.

Adolescents who were born extremely preterm demonstrate modest decreases in exercise capacity.

AIM: We aimed to investigate exercise capacity in adolescents who were born extremely preterm and to study changes through puberty and associations with neonatal data, exercise habits and lung function. METHODS: This Norwegian population-based controlled cohort study focused on all infants (n = 35) born at a gestational age of ≤ 28 weeks or with a birthweight of ≤ 1000 grams in 1991-1992, together with matched term-born controls. Participants underwent spirometry and a maximal cardiopulmonary treadmill exercise test at 10 and 18 years. RESULTS: At 18 years of age, mean (95% confidence interval) peak oxygen consumption (peak VO2 ) was 42.3 (39.2-45.4) vs 45.3 (41.3-49.3) mL/kg/min in the preterm- and term-born groups, while the completed treadmill distance was 915 (837-992) vs 1017 (912-1122) metres. Peak VO2 was unrelated to neonatal factors and current lung function. Changes between 10 and 18 were similar in the two groups, and positive associations between exercise habits and peak VO2 developed during the period. CONCLUSION: Exercise capacity was modestly reduced in adolescents born extremely preterm, but the values were considered normal in most participants. Changes during puberty were similar to those observed for term controls, and the findings suggest similar trainability.

A new non-invasive method of infant spirometry demonstrates a level of repeatability that is comparable to traditional methods.

AIM: The FloRight system provides novel non-invasive infant spirometry based on electromagnetic inductance plethysmography. We investigated the consistency of repeated measurements carried out in a Norwegian neonatal intensive care unit (NICU) using the system and how well these were tolerated. METHODS: Tidal flow-volume loops were obtained from 10 preterm infants at discharge, 10 stable growing preterm infants weighing about 1500 g and 10 term-born infants. A nurse experienced with the system measured all patients before and after meals, and these measurements were repeated by nurses new to the system. RESULTS: The measurements were well tolerated by the infants. The repeatability for the two parameters 'tidal volume' (Vt) and 'time to peak tidal expiratory flow to total expiratory time' (Tptef/Te) were relatively poor, similar to previous methods. However, the repeatability was good for the new 'flow-volume gravity mid-point' (FVg) parameter. Repeatability was better for term than preterm infants, when measurements were obtained by the experienced nurse and for measurements carried out before meals. CONCLUSION: The FloRight system proved feasible in a NICU setting. The repeatability of the lung function measurements was similar to those reported for traditional infant spirometry. The nurse's experience and the relationship to meals appeared to be important.

Health-related quality of life may deteriorate from adolescence to young adulthood after extremely preterm birth.

AIM: This study examined the development of health-related quality of life (HRQoL) and health from adolescence to adulthood after extremely preterm birth. METHODS: We assessed a population-based cohort of extremely preterm-born (EPB) infants (gestational age of ≤28 weeks or birthweight of ≤1000 grams) and term-born (TB) controls at 17 and 24 years of age. They completed the Child Health Questionnaire-Child Form 87 at 17 years of age, the Short Form Health Survey-36 (SF-36) at 24 years of age and the Health Behaviour in School-aged Children-Symptom Checklist at both ages. RESULTS: Of the 51 eligible EPB subjects, 46 (90%) were included and nine had severe neurosensory disabilities. On the whole, EPB and TB subjects gave their HRQoL and health similar ratings, but EPB subjects with disabilities reported poorer physical functioning at 17 and EPB subjects without disabilities reported lower scores on three of the eight SF-36 scales for social functioning and mental health and reported more psychological health complaints at 24. Differences remained in adjusted analyses. Changes from 17 to 24 years of age were minor in EPB subjects with disabilities. CONCLUSION: Our comparison of EPB and TB subjects at the ages of 17 and 24 indicated that psychosocial HRQoL may deteriorate for EPB subjects when they enter adulthood.