INTERGROWTH-21st v. local South African growth standards (Theron-Thompson) for identification of small-for-gestational-age fetuses in stillbirths : a closer look at variation across pregnancy

Lavin, T.Nedkoff, L.Preen, D.Theron, G.Pattinson, Robert Clive2020-07-092020-07-092019-07Lavin, T., Nedkoff, L., Preen, D. et al. 2019,' INTERGROWTH-21st v. local South African growth standards (Theron-Thompson) for identification of small-for-gestational-age fetuses in stillbirths : a closer look at variation across pregnant', South African Medical Journal, vol. 109, no. 7, pp. 519-525.2078-5135 (online)0256-9574 (print)10.7196/SAMJ.2019.v109i7.13485http://hdl.handle.net/2263/75105BACKGROUND: Global growth standards for fetuses were recently developed (INTERGROWTH-21st). It has been advocated that professional bodies should adopt these global standards. OBJECTIVES: To compare the ability of INTERGROWTH-21st with local standards (Theron-Thompson) to identify small-for-gestational-age (SGA) fetuses in stillbirths in the South African (SA) setting. METHODS: Stillbirths across SA were investigated (>500 g, 28 - 40 weeks) between October 2013 and December 2016 (N=14 776). The study applied the INTERGROWTH-21st standards to classify stillbirths as <10th centile (SGA) compared with Theron-Thompson growth charts, across pregnancy overall and at specific gestational ages. RESULTS: The prevalence of SGA was estimated at 32.2% and 31.1% by INTERGROWTH-21st and Theron-Thompson, respectively. INTERGROWTH-21st captured 13.8% more stillbirths as SGA in the earlier gestations (28 - 30 weeks, p<0.001), but 4.0% (n=315) fewer between 33 and 38 weeks (p<0.001). Observed agreement and the Kappa coefficient were lower at earlier gestations and at 34 - 36 weeks. CONCLUSIONS: Our findings demonstrated differences in the proportion of stillbirths considered SGA at each gestational age between the INTERGROWTH-21st and the local SA standard, which have not been considered previously by other studies.en© 2019, South African Medical Association. This article is licensed under a Creative Commons Attribution-NonCommercial Works License (CC BY-NC 3.0).PregnacyGestational ageFetusFetal growth monitoringStillbirthINTERGROWTH-21stSouth Africa (SA)Small-for-gestational-age (SGA)INTERGROWTH-21st v. local South African growth standards (Theron-Thompson) for identification of small-for-gestational-age fetuses in stillbirths : a closer look at variation across pregnancyArticle