{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,8,23]],"date-time":"2025-08-23T05:24:31Z","timestamp":1755926671776,"version":"3.37.3"},"reference-count":46,"publisher":"Public Library of Science (PLoS)","issue":"5","license":[{"start":{"date-parts":[[2022,5,10]],"date-time":"2022-05-10T00:00:00Z","timestamp":1652140800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Australian Research Council Centre of Excellence for Children and Families over the Life Course","award":["CE140100027"],"award-info":[{"award-number":["CE140100027"]}]},{"DOI":"10.13039\/501100001030","name":"Australian National Heart Foundation","doi-asserted-by":"crossref","award":["102549"],"award-info":[{"award-number":["102549"]}],"id":[{"id":"10.13039\/501100001030","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100000925","name":"National Health and Medical Research Council","doi-asserted-by":"publisher","award":["GNT1099655 and GNT1173991"],"award-info":[{"award-number":["GNT1099655 and GNT1173991"]}],"id":[{"id":"10.13039\/501100000925","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100005416","name":"Research Council of Norway","doi-asserted-by":"crossref","award":["262700"],"award-info":[{"award-number":["262700"]}],"id":[{"id":"10.13039\/501100005416","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"<jats:sec id=\"sec001\">\n<jats:title>Background<\/jats:title>\n<jats:p>This study investigated whether the timing of birth of the younger siblings was associated with the risk of the older siblings\u2019 developmental vulnerability in early childhood.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec002\">\n<jats:title>Methods<\/jats:title>\n<jats:p>Linkage of population-level birth registration, hospital, and perinatal datasets to Australian Early Development Census (AEDC) records (2009\u20132015), enabled follow-up of a cohort of 32,324 Western Australia born singletons. Children with scores &lt;10<jats:sup>th<\/jats:sup> percentile on an individual AEDC domain (Physical Health and Wellbeing; Social Competence; Emotional Maturity; Language and Cognitive Skills (school-based); and Communication Skills and General Knowledge) were classified as developmentally vulnerable. Modified Poisson Regression was used to estimate relative risks (RR) for associations between post-birth interpregnancy intervals (IPIs) and developmental vulnerability.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec003\">\n<jats:title>Results<\/jats:title>\n<jats:p>Relative to post-birth IPIs of 18\u201323 months, post-birth IPIs of &lt;6 and 6\u201311 months were associated with an increased risk of children being classified as DV1 (aRR 1.21, 95% CI: 1.11\u20131.31) and DV2 (aRR 1.31, 95% CI: 1.15\u20131.49); and DV1 (aRR 1.10, 95% CI: 1.03\u20131.17) and DV2 (aRR 1.21, 95% CI: 1.09\u20131.34), respectively. Post-birth IPIs of &lt;6 months were associated with an increased risk on four of the five AEDC domains. Post-birth IPIs of 48\u201360 months were associated with an increased risk of developmental vulnerability; however, the risk was statistically significant for DV1, DV2 and the domains of Emotional Maturity and Language and Cognitive Skills (school-based).<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec004\">\n<jats:title>Conclusions<\/jats:title>\n<jats:p>Developmental vulnerability was associated with having a closely spaced younger sibling (&lt;12 months post-birth IPIs). Optimising birth spacing should be further investigated as a potential means for improving child development outcomes.<\/jats:p>\n<\/jats:sec>","DOI":"10.1371\/journal.pone.0268325","type":"journal-article","created":{"date-parts":[[2022,5,10]],"date-time":"2022-05-10T17:26:37Z","timestamp":1652203597000},"page":"e0268325","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":4,"title":["Is early childhood development impeded by the birth timing of the younger sibling?"],"prefix":"10.1371","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5191-211X","authenticated-orcid":true,"given":"Gursimran","family":"Dhamrait","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Melissa","family":"O\u2019Donnell","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hayley","family":"Christian","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gavin","family":"Pereira","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"340","published-online":{"date-parts":[[2022,5,10]]},"reference":[{"issue":"1750","key":"pone.0268325.ref001","first-page":"20122313","article-title":"Are elder siblings helpers or competitors? 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