Maria Altman

Maternal overweight and obesity in early pregnancy and risk of infant mortality: a population based cohort study in Sweden

Objective To investigate associations between maternal overweight and obesity and infant mortality outcomes, including cause-specific mortality. Design Population based cohort study. Setting and participants 1u2009857u2009822 live single births in Sweden 1992–2010. Main outcome measures Associations between maternal body mass index (BMI) in early pregnancy and risks of infant, neonatal, and postneonatal mortality, overall and stratified by gestational length and by causes of infant death. Odds ratios were adjusted for maternal age, parity, smoking, education, height, country of birth, and year of delivery. Results Infant mortality rates increased from 2.4/1000 among normal weight women (BMI 18.5–24.9) to 5.8/1000 among women with obesity grade 3 (BMI ≥40.0). Compared with normal weight, overweight (BMI 25.0–29.9) and obesity grade 1 (BMI 30.0–34.9) were associated with modestly increased risks of infant mortality (adjusted odds ratios 1.25 (95% confidence interval 1.16 to 1.35) and 1.37 (1.22 to 1.53), respectively), and obesity grade 2 (BMI 35.0–39.9) and grade 3 were associated with more than doubled risks (adjusted odds ratios 2.11 (1.79 to 2.49) and 2.44 (1.88 to 3.17)). In analyses stratified by preterm and term births, maternal BMI was related to risks of infant mortality primarily in term births (≥37 weeks), where risks of deaths due to birth asphyxia and other neonatal morbidities increased with maternal overweight and obesity. Obesity grade 2–3 was also associated with increased infant mortality due to congenital anomalies and sudden infant death syndrome. Conclusions Maternal overweight and obesity are associated with increased risks of infant mortality due to increased mortality risk in term births and an increased prevalence of preterm births. Maternal overweight and obesity may be an important preventable risk factor for infant mortality in many countries.

Neonatal Morbidity in Moderately Preterm Infants: A Swedish National Population-Based Study

OBJECTIVEnTo determine the gestational age (GA)-specific risks for neonatal morbidity and use of interventions in infants born at 30 to 34 completed gestational weeks.nnnSTUDY DESIGNnA population-based Swedish study including 6674 infants born during 2004-2008. Risks for neonatal morbidity and use of interventions were investigated with respect to GA and birth weight standard deviation scores.nnnRESULTSnAcute lung disorder was diagnosed in 28%, hypoglycemia in 16%, bacterial infection in 15% and hyperbilirubinemia in 59% of the infants. Thirty-eight percent had received antenatal steroid therapy, 43% nasal continuous positive airway pressure, 5.5% required mechanical ventilation, 5.2% were treated with surfactant, and 30% with antibiotic therapy. Neonatal morbidity rates increased with decreasing GA, with odds ratios for different outcomes ranging from 2.1 to 23 at 30 weeks compared with 34 weeks of GA. Low birth weight standard deviation scores was more common at lower GA and was associated with increased morbidity rates.nnnCONCLUSIONSnDespite general advances in perinatal care, moderately preterm infants still have substantially increased risks for neonatal morbidity. Whereas the neonatal morbidity rate was similar to results of previous reports, management of respiratory problems differed markedly from other studies.

Moderately preterm infants and determinants of length of hospital stay

Background: Moderately preterm infants account for a large proportion of admissions and bed-days in neonatal units (NU). Management of these infants varies and determinants of length of stay are poorly studied. Objective: To determine postmenstrual age at hospital discharge for moderately preterm infants and its relation to perinatal risk factors and to organisation of care. Methods: Population-based cohort including 2388 infants, born in 2004–2005 with a gestational age (GA) of 30–34 weeks and admitted to 21 NU reporting to the Swedish perinatal register. Main outcome: postmenstrual age (PMA) at hospital discharge to home. Results: Mean PMA at hospital discharge was 36.9 (1.7) weeks. High (⩾35 years) maternal age, multiple birth, small for gestational age, respiratory distress syndrome, infection, hypoglycaemia and hyperbilirubinaemia were significantly associated with higher PMA at discharge, but could only explain 13% of the variation in PMA at discharge. Mean PMA at discharge differed by up to 2 weeks between hospitals. Infants treated at NUs without fixed discharge criteria had 4.7 days lower PMA at discharge and infants receiving domiciliary care had 9.8 days lower PMA at discharge. Breastfed infants also had lower PMA at discharge (mean 2.7 days lower) than those not breast fed, partly explained by lower morbidity in the breastfed infants. Conclusions: Perinatal risk factors have small overall impact on length of hospital stay in moderately preterm infants. Organisation of care is probably an important factor. The number of bed-days differs significantly between centres, which may have effects on quality of care and health economy.

Perinatal conditions related to growth restriction and inflammation are associated with an increased risk of bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is a frequent chronic lung disease in preterm infants, and we aimed to identify factors associated with this condition in infants with respiratory distress syndrome (RDS).

Risk factors for acute respiratory morbidity in moderately preterm infants.

BACKGROUNDnInfants born preterm account for a substantial part of neonatal morbidity, with acute respiratory disorders being a dominating clinical problem. Whereas focus in recent studies has been on extremely and very preterm infants, less is known about contemporary rates and risk factors for acute respiratory morbidity in moderately and late preterm infants. The objective of this population-based Swedish study was to establish rates for different acute respiratory diseases in moderately preterm infants, and to identify maternal, obstetric and neonatal risk factors for the two most common diagnoses, transient tachypnoea of the newborn (TTN) and respiratory distress syndrome (RDS).nnnMETHODSnThe study included 4679 moderately preterm [gestational age (GA): 30 to 34 weeks], 15u2009036 late preterm infants (GA 35 to 36 weeks) and 451u2009479 term infants (GA: 37 to 41 weeks). All infants were born in 2004-2008.nnnRESULTSnIn moderately preterm infants, risk factors for TTN in multivariable analyses were multiparity, caesarean section before and after onset of labour, male sex, Apgar score 4-6 at 5 min and lower GA. Risk factors for RDS were multiparity, caesarean section before and after onset of labour, male sex, Apgar score <7 at 5 min and lower GA. Preterm rupture of membranes, antenatal corticosteroid treatment and being small for gestational age reduced the risk of RDS.nnnCONCLUSIONnWe conclude that acute respiratory morbidity in moderately preterm infants is common and predicted by multiparity, caesarean section, low Apgar score and male sex.

Shorter hospital stay for moderately preterm infants.

Aim: To determine length of hospital stay (LOS) for moderately preterm infants during the last 20 years, and to identify factors affecting the number of bed‐days. Methods: Review of LOS for all infants delivered between 30 to 34 gestational weeks during 1983, 1988, 1993, 1998 and 2002. Exclusion criteria: life‐threatening abnormalities, chromosomal anomalies and death during hospitalization. Results: 564 included infants accounted for 20% of admissions and 48% of bed‐days in the neonatal unit. Between 1983 and 2002, maternal age and use of nasal continuous positive airway pressure increased, use of antibiotics and mechanical ventilation decreased, whereas distributions for gestational age, birthweight, gender, smallness for gestational age, low Apgar score or incidence of respiratory distress syndrome did not change. For healthy inborn singletons discharged home, LOS decreased from 1983 (28±11 d, mean±SD values) to 2002 (14±7 d, p<0.05). Infants born more immature had longer LOS, but postconceptional age at discharge did not differ between age groups.

Cause-specific infant mortality in a population-based Swedish study of term and post-term births: the contribution of gestational age and birth weight

Objective To investigate infant mortality and causes of infant death in relation to gestational age (GA) and birth weight for GA in non-malformed term and post-term infants. Design Observational, retrospective nationwide cohort study. Setting Sweden 1983–2006. Participants 2u2008152u2008738 singleton non-malformed infants born at 37 gestational weeks or later. Main outcome measures Infant, neonatal and postneonatal mortality and causes of infant death. Results Infant mortality rate was 0.12% (n=2687). Compared with infants born at 40u2005weeks, risk of infant mortality was increased among early term infants (37u2005weeks, adjusted OR 1.70, 95% CI 1.43 to 2.02). Compared with infants with normal birth weight for GA, very small for gestational age (SGA; <3rd percentile) infants faced a doubled risk of infant mortality (adjusted OR 2.13, 95% CI 1.80 to 2.53), and corresponding risk was also increased among moderately SGA infants (3rd to <10th percentile; adjusted OR 1.46, 95% CI 1.26 to 1.68). Sudden infant death syndrome (SIDS) was the most common cause of death, accounting for 39% of all infant mortality. Compared with birth at 40u2005weeks, birth at 37u2005weeks was associated with increased risks of death by infections, cardiovascular disorders, SIDS and malignant neoplasms. Very and moderately SGA were associated with increased risks of death by neonatal respiratory disorders, infections, cardiovascular disorders, SIDS and neuromuscular disorders. High birth weight for GA was associated with increased risks of death by asphyxia and malignant neoplasms. Conclusion Early term birth and very to moderately low birth weight for GA are independent risk factors for infant mortality among non-malformed term infants.

Prenatal inflammatory risk factors for development of bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is a serious, chronic lung disease affecting preterm infants.

Prolonged second stage of labor is associated with low Apgar score

There is no consensus on the effects of a prolonged second stage of labor on neonatal outcomes. In this large Swedish population-based cohort study, our objective was to investigate prolonged second stage and risk of low Apgar score at 5xa0min. All nulliparous women (nxa0=xa032,796) delivering a live born singleton infant in cephalic presentation at ≥37 completed weeks after spontaneous onset of labor between 2008 and 2012 in the counties of Stockholm and Gotland were included. Data were obtained from computerized records. Exposure was time from fully retracted cervix until delivery. Logistic regression analyses were used to estimate crude and adjusted odds ratios (ORs) with 95xa0% confidence intervals (CIs). Adjustments were made for maternal age, height, BMI, smoking, sex, gestational age, sex-specific birth weight for gestational age and head circumference. Epidural analgesia was included in a second model. The primary outcome measure was Apgar score at 5xa0min <7 and <4. We found that the overall rates of 5xa0min Apgar score <7 and <4 were 7.0 and 1.3 per 1000 births, respectively. Compared to women with <1xa0h from retracted cervix to birth, adjusted ORs of Apgar score <7 at 5xa0min generally increased with length of second stage of labor: 1 to <2xa0h: OR 1.78 (95xa0% CI 1.19–2.66); 2 to <3xa0h: OR 1.66 (1.05–2.62); 3 to <4xa0h: OR 2.08 (1.29–3.35); and ≥4xa0h: OR 2.71 (1.67–4.40). We conclude that prolonged second stage of labor is associated with an increased risk of low 5xa0min Apgar score.

Early Provision of Mother's Own Milk and Other Predictors of Successful Breast Milk Feeding after Very Preterm Birth: A Regional Observational Study.

Background: Breast milk is associated with a lower risk of neonatal morbidity in very preterm infants. Despite the benefits, the duration of breastfeeding is shorter in very preterm infants than in term infants. Objective: This study aimed to investigate how early provision of mother’s own milk (MOM) and maternal and infant characteristics are related to breast milk feeding (BMF) between 36 and 40 weeks postmenstrual age (PMA) after very preterm birth. Methods: A regional observational study of 138 singleton infants born at < 32 weeks of gestation in Stockholm, Sweden, was conducted. Data were derived from medical charts to investigate the association between early provision of MOM; maternal and infant characteristics; and exclusive, partial, or no BMF at 36 weeks PMA. Moreover, changes in BMF between 36 and 40 weeks PMA were studied. Results: Most infants (80%) received MOM at 36 weeks PMA (55% exclusively, 25% partial). High provision of MOM at postnatal day 7 was associated with exclusive BMF at 36 weeks PMA, odds ratio (OR) 1.18 per 10 mL/kg MOM (95% confidence interval [CI], 1.06-1.32). Mothers born in non-Nordic countries provided MOM exclusively less often, adjusted OR 0.27 (95% CI, 0.10-0.69), compared to Nordic mothers. Between 36 and 40 weeks PMA, BMF decreased overall. This change was not associated with investigated predictors. Conclusion: It is possible to achieve high rates of BMF in very preterm infants. High intake of MOM early in the postnatal period is strongly related to exclusive BMF at 36 weeks PMA.