Abstract
Background. Maternal low birth weight (LBW), preterm birth (PTB) and small-for-gestational age (SGA) birth status have been suggested as precursors for an infant being born LBW, PTB or SGA. Objective. To systematically review the risks of infant LBW/PTB/SGA among mothers who were LBW/PTB/SGA. Search strategy. Medline, Embase, CINAHL and bibliographies of identified articles were searched for English language studies. Selection criteria. Studies reporting association between maternal birth status and LBW, PTB or SGA outcomes were included. Study quality was assessed for biases in selection, exposure assessment, confounder adjustment, analyses, outcomes assessment and attrition. Data collection and analysis. Unadjusted data from included studies were extracted by two reviewers. Summary odds ratio (OR) and confidence intervals (CI) were calculated using random effect model. Main results. Twenty-two studies of low to moderate risk of biases were included. Maternal LBW was associated with infant LBW (12 studies, 525,706 participants, OR 2.23, 95% CI 2.11–2.35), PTB (six studies, 331,121 participants, OR 1.57, 95% CI 1.43–1.71) and SGA (three studies, 324,357 participants, OR 1.83, 95% CI 1.43–2.33). Maternal PTB was associated with infant PTB (seven studies, 282,616 participants, OR 1.41, 95% CI 1.26–1.59) and SGA (three studies, 41,590 participants, OR 1.33, 95% CI 1.08–1.64). Maternal SGA was associated with infant PTB (OR 1.58, 95% CI 1.06–2.37) and SGA (OR 2.64, 95% CI 2.28–3.05). Conclusions. Maternal LBW, PTB or SGA status was associated with their children's LBW/PTB/SGA status. Maternal birth status should be included in risk assessment when planning pregnancy care for individual women.
Acknowledgements
We thank Elizabeth Uleryk, Chief Librarian at the Hospital for Sick Children, Toronto, for her contribution in developing the search strategy and running searches on a periodic basis.
This study was supported by funding from Canadian Institute of Health Research (CIHR) Knowledge Synthesis/Translation grant # KRS 86242. CIHR has no role in analyses, writing of the report, interpretation of data or decision to submit the manuscript.
Declaration of interest: The authors reports no conflicts of interest. The authors alone are responsible for the content and writing of the paper.