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Does caesarean delivery in the first pregnancy increase the risk for adverse outcome in the second? A registry-based cohort study on first and second singleton births in Norway
  1. Solveig Bjellmo1,2,
  2. Guro L Andersen2,3,
  3. Sissel Hjelle1,
  4. Kari Klungsøyr4,5,
  5. Lone Krebs6,7,
  6. Stian Lydersen8,
  7. Pål Richard Romundstad9,
  8. Torstein Vik2
  1. 1 Obstetrics and Gynecology, Helse More og Romsdal HF, Aalesund, Norway
  2. 2 Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
  3. 3 The Cerebral Palsy Registry of Norway, Habilitation Center, Vestfold Hospital, Tønsberg, Norway
  4. 4 Division of Mental and Physical Health, Norwegian Institute of Public Health, Oslo, Norway
  5. 5 Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway
  6. 6 Obstetrics and Gynaecology, Amager Hvidovre Hospital, Hvidovre, Denmark
  7. 7 Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
  8. 8 Regional Centre for Child and Youth Mental Health and Child Welfare, Norwegian University of Science and Technology, Trondheim, Norway
  9. 9 Department of Public Health, Norwegian University of Science and Technology, Trondheim, Norway
  1. Correspondence to Dr Solveig Bjellmo; solveigbjellmo{at}


Objective To explore if newborns in the second pregnancy following a previous caesarean delivery (CD) have higher risk of perinatal mortality or cerebral palsy than newborns in pregnancies following a previous vaginal delivery (VD).

Design Cohort study with information from the Medical Birth Registry of Norway and the Cerebral Palsy Registry of Norway.

Setting Births in Norway.

Participants 294 598 women with their first and second singleton delivery during 1996–2015.

Main outcome measures Stillbirth, perinatal mortality, neonatal mortality and cerebral palsy.

Results Among 294 598 included women, 42 962 (15%) had a CD in their first pregnancy while 251 636 (85%) had a VD. Compared with the second delivery of mothers with a previous VD, the adjusted OR (adjOR), for stillbirth in the second pregnancy following a previous CD was 1.45, 95% CI 1.22 to 1.73; for perinatal death the adjOR was 1.42 (1.22 to 1.73) and for neonatal death 1.13 (0.86 to 1.49). Among children who survived the neonatal period, the adjOR for cerebral palsy was 1.27 (0.99 to 1.64). Secondary outcomes, including small for gestational age, preterm and very preterm birth, uterine rupture and placental complications (eg, postpartum haemorrhage and pre-eclampsia) were more frequent in the subsequent pregnancy following a previous CD compared with a previous VD, in particular for uterine rupture adjOR 86.7 (48.2 to 156.1). Adjustment for potential confounders attenuated the ORs somewhat, but the excess risk in the second pregnancy persisted for all outcomes.

Conclusion A previous CD was in this study associated with increased risk for stillbirth and perinatal death compared with a previous VD. Although less robust, we also found that a previous CD was associated with a slightly increased risk of cerebral palsy among children surviving the neonatal period. The aetiology behind these associations needs further investigation.

  • obstetrics
  • epidemiology
  • neonatology
  • maternal medicine

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  • Contributors SB proposed the research question, analysed the data, contributed to study design and data interpretation and wrote the first draft of the manuscript. GLA was principally responsible for the data from the CPRN and revised the manuscript. LK contributed to the data interpretation and revised the manuscript. KK contributed to the study design, the analyses and interpretation of the data and revised the manuscript. SH contribute to the data interpretation and revised the manuscript. PRR contributed to the data interpretation and revised the manuscript. SL was responsible for the statistical methods, the interpretation of the results and revised the manuscript. TV contributed to the research question, the study design, the analyses and the interpretation of the data and the revision of the manuscript. All authors approved the final version of the submitted manuscript.

  • Funding Supported by a grant from The Liaison Committee between the Central Norway Regional Health Authority (RHA) and the Norwegian University of Science and Technology (NTNU).

  • Competing interests All authors have completed the ICMJE uniform disclosure form at (available on request from the corresponding author) and declare: no financial support from any organisation for the submitted work; no financial relationship with any companies that might have an interest in the submitted work in the previous three years; and have no non-financial interests or relationships that may be relevant to the submitted work.

  • Patient consent for publication Not required.

  • Ethics approval The study was approved by the Regional Ethical Committee for Medical Research in Mid-Norway (ref 2018/2145). We intend to present results directly to the Association for persons with cerebral palsy. In addition, dissemination to the Norwegian population (which constitutes the study population) and the broader public will be achieved through media outreach or other public presentations.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement Data may be obtained from a third party and are not publicly available. No data are available. For question regarding the analyses of the data, please contact the corresponding author at: The protocol is also available on request.