title: Asthma during pregnancy in a population-based study--pregnancy complications and adverse perinatal outcomes.
abstract: BACKGROUND
  Asthma is one of the most common chronic diseases, and prevalence, severity and medication may have an effect on pregnancy. We examined maternal asthma, asthma severity and control in relation to pregnancy complications, labour characteristics and perinatal outcomes.
  
  
  METHODS
  We retrieved data on all singleton births from July 1, 2006 to December 31, 2009, and prescribed drugs and physician-diagnosed asthma on the same women from multiple Swedish registers. The associations were estimated with logistic regression.
  
  
  RESULTS
  In total, 266 045 women gave birth to 284 214 singletons during the study period. Maternal asthma was noted in 26 586 (9.4%) pregnancies. There was an association between maternal asthma and increased risks of pregnancy complications including preeclampsia or eclampsia (adjusted OR 1.15; 95% CI 1.06-1.24) and premature contractions (adj OR 1.52; 95% CI 1.29-1.80). There was also a significant association between maternal asthma and emergency caesarean section (adj OR 1.29; 95% CI 1.23-1.34), low birth weight, and small for gestational age (adj OR 1.23; 95% CI 1.13-1.33). The risk of adverse outcomes such as low birth weight increased with increasing asthma severity. For women with uncontrolled compared to those with controlled asthma the results for adverse outcomes were inconsistent displaying both increased and decreased OR for some outcomes.
  
  
  CONCLUSIONS
  Maternal asthma is associated with a number of serious pregnancy complications and adverse perinatal outcomes. Some complications are even more likely with increased asthma severity. With greater awareness and proper management, outcomes would most likely improve.
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Obstetrics and Gynaecology Unit, Södersjukhuset, Stockholm, Sweden.
authors.forename: Gustaf
authors.initials: G
authors.lastname: Rejnö
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Lundholm
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Tong
authors.initials: T
authors.lastname: Gong
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Kjell
authors.initials: K
authors.lastname: Larsson
authors.affiliation: Department of Clinical Science and Education, Södersjukhuset, Karolinska Institutet, Stockholm, Sweden; Obstetrics and Gynaecology Unit, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Sissel
authors.initials: S
authors.lastname: Saltvedt
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Astrid Lindgren Children's Hospital, Lung and Allergy Unit, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Catarina
authors.initials: C
authors.lastname: Almqvist
mesh_terms: D000328:Adult; D001249:Asthma / Q000453:epidemiology*; D015897:Comorbidity; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008423:Maternal Age; D011225:Pre-Eclampsia / Q000453:epidemiology*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D011256:Pregnancy Outcome; D047928:Premature Birth / Q000453:epidemiology*; D015995:Prevalence; D012042:Registries; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology; D055815:Young Adult