Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Epidemiology and Population Health

Pre-pregnancy body mass index and adverse maternal and perinatal outcomes in twins: A population retrospective cohort study



To examine the association between pre-pregnancy BMI and severe maternal morbidity (SMM), perinatal death and severe neonatal morbidity in twin pregnancies.


All twin births at ≥ 20 weeks gestation in British Columbia, Canada, from 2000 to 2017 were included. We estimated rates of SMM, a perinatal composite of death and severe morbidity, and its components per 10,000 pregnancies. Confounder-adjusted rate ratios (aRR) between pre-pregnancy BMI and outcomes were estimated using robust Poisson regression.


Overall, 7770 (368 underweight, 1704 overweight, and 1016 obese) women with twin pregnancy were included. The rates of SMM were: 271.1, 320.4, 270.0, and 225.9 in underweight, normal BMI, overweight and obese women, respectively. There was little association between obesity and any of the primary outcomes (e.g., aRR = 1.09, 95% CI = 0.85, 1.38 for composite perinatal outcome). Underweight women had higher rates of the composite perinatal adverse outcome (aRR = 1.79, 95% CI = 1.32–2.43), driven by increased rates of severe respiratory distress syndrome, and neonatal death.


There was no evidence of elevated risk of adverse outcomes among twin pregnancies of women who were overweight or obese. Risk was higher in underweight women, who may require specific care when carrying twins.

This is a preview of subscription content, access via your institution

Access options

Rent or buy this article

Prices vary by article type



Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Adjusted risk of adverse outcomes by pre-pregnancy body-mass-index.

Data availability

Access to data provided by the Data Steward(s) is subject to approval but can be requested for research projects through the Data Steward(s) or their designated service providers. All inferences, opinions, and conclusions drawn in this publication are those of the author(s), and do not reflect the opinions or policies of the Data Steward(s).


  1. Chen C, Xu X, Yan Y. Estimated global overweight and obesity burden in pregnant women based on panel data model. PLoS ONE 2018;13.

  2. Driscoll AK. Increases in Prepregnancy Obesity: United States, 2016–2019. 2020;392:1–8.

  3. Devlieger R, Benhalima K, Damm P, Van Assche A, Mathieu C, Mahmood T, et al. Maternal obesity in Europe: Where do we stand and how to move forward?: A scientific paper commissioned by the European Board and College of Obstetrics and Gynaecology (EBCOG). Eur J Obstet Gynecol Reprod Biol. 2016;201:203–8.

    Article  PubMed  Google Scholar 

  4. Heslehurst N, Rankin J, Wilkinson JR, Summerbell CD. A nationally representative study of maternal obesity in England, UK: Trends in incidence and demographic inequalities in 619 323 births, 1989–2007. Int J Obes. 2010;34:420–8.

    Article  CAS  Google Scholar 

  5. Lisonkova S, Muraca GM, Potts J, Liauw J, Chan W-S, Skoll A, et al. Association between prepregnancy body mass index and severe maternal morbidity. JAMA. 2017;318:1777–86.

    Article  PubMed  PubMed Central  Google Scholar 

  6. Aune D, Saugstad OD, Henriksen T, Tonstad S. Maternal body mass index and the risk of fetal death, stillbirth, and infant death: A systematic review and meta-analysis. JAMA. 2014;311:1536–46.

    Article  CAS  PubMed  Google Scholar 

  7. Chu SY, Kim SY, Lau J, Schmid CH, Dietz PM, Callaghan WM, et al. Maternal obesity and risk of stillbirth: A metaanalysis. Am J Obstet Gynecol. 2007;197:223–8.

    Article  PubMed  Google Scholar 

  8. Cheong-See F, Schuit E, Arroyo-Manzano D, Khalil A, Barrett J, Joseph KS, et al. Prospective risk of stillbirth and neonatal complications in twin pregnancies: Systematic review and meta-analysis. BMJ. 2016;354:i4353.

    Article  PubMed  PubMed Central  Google Scholar 

  9. Madar H, Goffinet F, Seco A, Rozenberg P, Dupont C, Deneux-Tharaux C. Severe acute maternal morbidity in twin compared with singleton pregnancies. Obstet Gynecol. 2019;133:1141–50.

    Article  PubMed  Google Scholar 

  10. Chauhan SP, Scardo JA, Hayes E, Abuhamad AZ, Berghella V. Twins: Prevalence, problems, and preterm births. Am J Obstet Gynecol. 2010;203:305–15.

    Article  PubMed  Google Scholar 

  11. Ram M, Berger H, Lipworth H, Geary M, McDonald SD, Murray-Davis B, et al. The relationship between maternal body mass index and pregnancy outcomes in twin compared with singleton pregnancies. Int J Obes. 2020;44:33–44.

    Article  Google Scholar 

  12. Al-Obaidly S, Parrish J, Murphy KE, Maxwell C. Maternal pre-gravid body mass index and obstetric outcomes in twin gestations. J Perinatol. 2014;34:425–8.

    Article  CAS  PubMed  Google Scholar 

  13. Perinatal Services BC. British Columbia Perinatal Data Registry. Years Provided: (2000 to 2017). Resource Type: Data Extract. Data Provided on (2020).

  14. Frosst G, Hutcheon J, Joseph K, Kinniburgh B, Johnson C, Lee L. Validating the British Columbia perinatal data registry: A chart re-abstraction study. BMC Preg Childbirth 2015;15.

  15. Dzakpasu S, Deb-Rinker P, Arbour L, Darling EK, Kramer MS, Liu S, et al. Severe maternal morbidity surveillance: Monitoring pregnant women at high risk for prolonged hospitalisation and death. Paediatr Perinat Epidemiol. 2020;34:427–39.

    Article  PubMed  Google Scholar 

  16. Greenland S, Pearce N. Statistical foundations for model-based adjustments. Annu Rev Public Health. 2015;36:89–108.

    Article  PubMed  Google Scholar 

  17. Greenland S. Interval estimation by simulation as an alternative to and extension of confidence intervals. Int J Epidemiol. 2004;33:1389–97.

    Article  PubMed  Google Scholar 

  18. Targeted Learning - Causal Inference for Observational and Experimental Data | Mark J. van der Laan | Springer. (accessed 12 Apr 2021).

  19. Balzer LB, Zheng W, van der Laan MJ, Petersen ML. A new approach to hierarchical data analysis: Targeted maximum likelihood estimation for the causal effect of a cluster-level exposure. Stat Methods Med Res. 2019;28:1761–80.

    Article  PubMed  Google Scholar 

  20. Benkeser D, Carone M, Laan MJVD, Gilbert PB. Doubly robust nonparametric inference on the average treatment effect. Biometrika. 2017;104:863–80.

    Article  CAS  PubMed  Google Scholar 

  21. VanderWeele TJ, Ding P. Sensitivity analysis in observational research: Introducing the E-value. Ann Intern Med. 2017;167:268–74.

    Article  PubMed  Google Scholar 

  22. Bone JN, Joseph KS, Mayer C, Platt R, Lisonkova S. The association between pre-pregnancy body mass index and perinatal death and the role of gestational age at delivery. PLOS ONE. 2022;17:e0264565.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  23. Fox NS, Roman AS, Saltzman DH, Klauser CK, Rebarber A. Obesity and adverse pregnancy outcomes in twin pregnancies. J Matern-Fetal Neonatal Med Off J Eur Assoc Perinat Med Fed Asia Ocean Perinat Soc Int Soc Perinat Obstet. 2014;27:355–9.

    CAS  Google Scholar 

  24. Lucovnik M, Blickstein I, Verdenik I, Trojner-Bregar A, Tul N. Maternal obesity in singleton versus twin gestations: A population-based matched case–control study. J Matern Fetal Neonatal Med. 2015;28:623–5.

    Article  PubMed  Google Scholar 

  25. Lučovnik M, Tul N, Verdenik I, Novak Z, Blickstein I. Risk factors for preeclampsia in twin pregnancies: A population-based matched case-control study. J Perinat Med. 2012;40:379–82.

    Article  PubMed  Google Scholar 

  26. Simões T, Queirós A, Correia L, Rocha T, Dias E, Blickstein I. Gestational diabetes mellitus complicating twin pregnancies. 2011;39:437–40.

    Google Scholar 

  27. Suzuki S, Yoneyama Y, Sawa R, Shin S, Araki T. Clinical usefulness of maternal body mass index in twin pregnancies. Hypertens Pregnancy. 2000;19:273–9.

    Article  CAS  PubMed  Google Scholar 

  28. Salihu HM, Alio AP, Belogolovkin V, Aliyu MH, Wilson RE, Reddy UM, et al. Prepregnancy obesity and risk of stillbirth in viable twin gestations. Obesity. 2010;18:1795–1800.

    Article  PubMed  Google Scholar 

  29. Yao R, Ananth CV, Park BY, Pereira L, Plante LA. Obesity and the risk of stillbirth: A population-based cohort study. Am J Obstet Gynecol. 2014;210:457.e1–457.e9.

    Article  PubMed  Google Scholar 

  30. Lu GC, Rouse DJ, DuBard M, Cliver S, Kimberlin D, Hauth JC. The effect of the increasing prevalence of maternal obesity on perinatal morbidity. Am J Obstet Gynecol. 2001;185:845–9.

    Article  CAS  PubMed  Google Scholar 

  31. Scott G, Gillon TE, Pels A, Dadelszen P von, Magee LA. Guidelines—similarities and dissimilarities: a systematic review of international clinical practice guidelines for pregnancy hypertension. Am J Obstet Gynecol. 2020;0.

  32. Kristensen J, Vestergaard M, Wisborg K, Kesmodel U, Secher NJ. Pre-pregnancy weight and the risk of stillbirth and neonatal death. BJOG Int J Obstet Gynaecol. 2005;112:403–8.

    Article  Google Scholar 

  33. Marleen S, Dias C, Nandasena R, MacGregor R, Allotey J, Aquilina J, et al. Association between chorionicity and preterm birth in twin pregnancies: A systematic review involving 29 864 twin pregnancies. BJOG Int J Obstet Gynaecol. 2021;128:788–96.

    Article  CAS  Google Scholar 

  34. Salihu HM, Dunlop A-L, Hedayatzadeh M, Alio AP, Kirby RS, Alexander GR. Extreme obesity and risk of stillbirth among black and white gravidas. Obstet Gynecol. 2007;110:552–7.

    Article  PubMed  Google Scholar 

  35. Pasquali R, Patton L, Gambineri A. Obesity and infertility. Curr Opin Endocrinol Diabetes Obes. 2007;14:482–7.

    Article  PubMed  Google Scholar 

  36. Lisonkova S, Joseph KS. Left truncation bias as a potential explanation for the protective effect of smoking on preeclampsia. Epidemiol Camb Mass. 2015;26:436–40.

    Article  Google Scholar 

  37. Sapra KJ, Chaurasia AK, Hutcheon JA, Ahrens KA. Reconstructing a pregnancy cohort to examine potential selection bias in studies on racial disparities in preterm delivery. Paediatr Perinat Epidemiol. 2017;31:55–63.

    Article  PubMed  Google Scholar 

  38. Hernan MA, Robins J. Causal Inference: What if. Boca Raton: Chapman & Hill/CRC. 2020.

  39. Lisonkova S, Joseph KS, Bell R, Glinianaia SV. Effect of advanced maternal age on perinatal outcomes in twins: The impact of chorionicity. Ann Epidemiol. 2013;23:428–34.

    Article  PubMed  Google Scholar 

  40. Sung SJ, Lee SM, Kim S, Kim BJ, Park C-W, Park JS, et al. The risk of spontaneous preterm birth according to maternal pre-pregnancy body mass index in twin gestations. J Korean Med Sci. 2018; 33.

  41. Gete DG, Waller M, Mishra GD. Effects of maternal diets on preterm birth and low birth weight: A systematic review. Br J Nutr. 2020;123:446–61.

    Article  CAS  PubMed  Google Scholar 

  42. Smith C, Teng F, Branch E, Chu S, Joseph KS. Maternal and perinatal morbidity and mortality associated with anemia in pregnancy. Obstet Gynecol. 2019;134:1234–44.

    Article  PubMed  PubMed Central  Google Scholar 

  43. Jung J, Rahman MM, Rahman MS, Swe KT, Islam MR, Rahman MO, et al. Effects of hemoglobin levels during pregnancy on adverse maternal and infant outcomes: A systematic review and meta-analysis. Ann N Y Acad Sci. 2019;1450:69–82.

    PubMed  Google Scholar 

  44. Ante Z, Luu TM, Healy-Profitós J, He S, Taddeo D, Lo E, et al. Pregnancy outcomes in women with anorexia nervosa. Int J Eat Disord. 2020;53:403–12.

    Article  PubMed  Google Scholar 

  45. Yu Y-H, Bodnar LM, Brooks MM, Himes KP, Naimi AI. Comparison of parametric and nonparametric estimators for the association between incident prepregnancy obesity and stillbirth in a population-based cohort study. Am J Epidemiol. 2019;188:1328–36.

    Article  PubMed  PubMed Central  Google Scholar 

Download references


The authors would like to thank Dr. Cande Anath for his thoughtful feedback on a previous version of this manuscript.


This study was supported by funding from the Sick Kids Foundations (grant number SKF-154852). JB is supported by a four-year PhD fellowship award from the University of British Columbia (award number 6456). KSJ is supported by an Investigator award from the BC Children’s Hospital Research Institute. SL is supported by a scholar award from the Michael Smith Foundation for Health Research. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. All inferences, opinions and conclusions drawn in this paper are those of the authors and do not reflect the opinions or policies of the Data Stewards.

Author information

Authors and Affiliations



SL and JB designed the study and formulated the research question. JB analyzed the data and wrote the first draft of the manuscript with supervision from SL. KS, LAM, LW, and CM read and reviewed the manuscript and provided critical feedback and suggested additional analyses. All authors approved the final version.

Corresponding author

Correspondence to Jeffrey N. Bone.

Ethics declarations

Competing interests

The authors declare no competing interests.

Ethical approval

Ethics approval for this study was obtained from the University of British Columbia - Children’s and Women’s Hospital and Health Centre of British Columbia Research Ethics Board (H18–03154).

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and Permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Bone, J.N., Joseph, K.S., Magee, L.A. et al. Pre-pregnancy body mass index and adverse maternal and perinatal outcomes in twins: A population retrospective cohort study. Int J Obes 47, 799–806 (2023).

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:


Quick links