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Outcomes of singleton small for gestational age preterm infants exposed to maternal hypertension: a retrospective cohort study



Hypertensive disorders of pregnancy (HDP) are a major cause of small for gestational age (SGA). Preterm SGA infants have higher rates of adverse outcomes than appropriate for gestational age infants. However, the outcomes are not well established in the setting of HDP.


Retrospective population-based study using the Canadian Neonatal Network database from January 1, 2010 to December 31, 2016 of SGA infants <33 weeks gestation. Using multivariable models, we determined the adjusted odds ratios (AORs) with 95% confidence intervals (CI) for mortality, bronchopulmonary dysplasia (BPD), severe intraventricular hemorrhage (IVH), severe retinopathy of prematurity, necrotizing enterocolitis, late-onset sepsis, and patent ductus arteriosus (PDA) in infants of HDP mothers and compared them to infants of non-HDP mothers.


Of the 2081 eligible SGA infants, 1317 (63%) were born to HDP mothers and had lower odds of mortality (AOR 0.57, 95% CI 0.39–0.83) and BPD (AOR 0.69, 95% CI 0.53–0.90). Sub-group analysis demonstrated decreased mortality in 26–28 and 29–32 weeks gestation groups, decreased BPD in 29–32 weeks gestation group, and decreased PDA in <26 weeks gestation group.


Preterm SGA infants of HDP mothers have lower odds of mortality and BPD compared to infants of non-HDP mothers.

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Members of the Canadian Neonatal Network can be found in the Supplemental Authors List (online).


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We gratefully acknowledge all site investigators and abstractors of the Canadian Neonatal Network (CNN) and Canadian Neonatal Follow-up Network (CNFUN). We also thank the staff at the Maternal-Infant Care (MiCare) Research Center at Mount Sinai Hospital, Toronto, ON, Canada for organizational support of the CNN, CNFUN, and this project. In addition, we thank Eugene W. Yoon, MSc, for statistical analysis assistance, as well as Sarah Hutchinson, PhD, and Iris Kulbatski, PhD, from MiCare for editorial assistance, in the preparation of this manuscript. MiCare is supported by a team grant from the Canadian Institutes of Health Research (CTP 87518), the Ontario Ministry of Health, and support from participating hospitals. P.S.S. holds an Applied Research Chair in Reproductive and Child Health Services and Policy Research awarded by the CIHR (APR-126340). The funding agencies had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

Author information

K.Y.: Conception, design, interpretation, revised the manuscript, and finalized the manuscript. E.E.: Design, interpretation of data, and revised the manuscript. S.D.: Acquisition of data and revised the manuscript. W.Y.: Acquisition of data and revised the manuscript. E.P.: Acquisition of data and revised manuscript. R.C.: Acquisition of data and revised the manuscript. P.S.S.: Analysis of data, interpretation of data, revised manuscript, and final approval of the manuscript.

Competing interests

The authors declare no competing interests.

Correspondence to Kamran Yusuf.

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