{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,5]],"date-time":"2026-01-05T11:11:28Z","timestamp":1767611488612},"reference-count":46,"publisher":"Wiley","issue":"6","license":[{"start":{"date-parts":[[2019,8,19]],"date-time":"2019-08-19T00:00:00Z","timestamp":1566172800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Influenza Resp Viruses"],"published-print":{"date-parts":[[2019,11]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Background<\/jats:title><jats:p>The estimated association of maternal influenza vaccination and birth outcomes may be sensitive to methods used to define preterm birth or small\u2010for\u2010gestational age (SGA).<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>In a cohort of pregnant women in Lao People's Democratic Republic, we estimated gestational age from: (a) date of last menstrual period (LMP), (b) any prenatal ultrasound, (c) first trimester ultrasound, (d) Ballard Score at delivery, and (e) an algorithm combining LMP and ultrasound. Infants were classified as SGA at birth using a Canadian, global, and equation\u2010based growth reference. We estimated the association of maternal influenza vaccination and birth outcomes, by influenza activity, using multivariable log\u2010binomial regression and Cox proportional hazards regression with vaccination as a time\u2010varying exposure.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>The frequency of preterm birth in the cohort varied by method to estimate gestational age, from 5% using Ballard Score to 15% using any ultrasound. Using LMP, any ultrasound, or the algorithm, we found statistically significant reductions in preterm birth among vaccinated women during periods of high influenza activity and statistically significant increases in SGA, using a Canadian growth reference. We did not find statistically significant associations with SGA when using global or equation\u2010based growth references.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>The association of maternal influenza vaccination and birth outcomes was most affected by the choice of a growth reference used to define SGA at birth. The association with pre\u2010term birth was present and consistent across multiple statistical approaches. Future studies of birth outcomes, specifically SGA, should carefully consider the potential for bias introduced by measurement choice.<\/jats:p><\/jats:sec>","DOI":"10.1111\/irv.12673","type":"journal-article","created":{"date-parts":[[2019,8,19]],"date-time":"2019-08-19T12:46:06Z","timestamp":1566218766000},"page":"547-555","update-policy":"http:\/\/dx.doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Measurement of birth outcomes in analyses of the impact of maternal influenza vaccination"],"prefix":"10.1111","volume":"13","author":[{"given":"Melissa A.","family":"Rolfes","sequence":"first","affiliation":[{"name":"Influenza Division Centers for Disease Control and Prevention Atlanta Georgia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Phouvanh","family":"Vonglokham","sequence":"additional","affiliation":[{"name":"Ministry of Health Vientiane Lao People's Democratic Republic"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Viengphone","family":"Khanthamaly","sequence":"additional","affiliation":[{"name":"Influenza Program U.S. CDC\u2010Lao PDR, American Embassy Vientiane Lao People's Democratic Republic"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bounlap","family":"Chitry","sequence":"additional","affiliation":[{"name":"Mother and Child Hospital Vientiane Lao People's Democratic Republic"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Vathsana","family":"Pholsena","sequence":"additional","affiliation":[{"name":"Setthathirat Hospital Vientiane Lao People's Democratic Republic"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Visith","family":"Chitranondh","sequence":"additional","affiliation":[{"name":"Luang Prabang Provincial Hospital Luang Prabang Lao People's Democratic Republic"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sara A.","family":"Mirza","sequence":"additional","affiliation":[{"name":"Influenza Division Centers for Disease Control and Prevention Atlanta Georgia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ann","family":"Moen","sequence":"additional","affiliation":[{"name":"Influenza Division Centers for Disease Control and Prevention Atlanta Georgia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Joseph S.","family":"Bresee","sequence":"additional","affiliation":[{"name":"Influenza Division Centers for Disease Control and Prevention Atlanta Georgia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Anonh","family":"Xeuatvongsa","sequence":"additional","affiliation":[{"name":"Ministry of Health Vientiane Lao People's Democratic Republic"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sonja J.","family":"Olsen","sequence":"additional","affiliation":[{"name":"Influenza Division Centers for Disease Control and Prevention Atlanta Georgia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2019,8,19]]},"reference":[{"key":"e_1_2_5_2_1","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa1401480"},{"key":"e_1_2_5_3_1","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa0708630"},{"key":"e_1_2_5_4_1","doi-asserted-by":"publisher","DOI":"10.1016\/S1473-3099(16)30054-8"},{"key":"e_1_2_5_5_1","doi-asserted-by":"publisher","DOI":"10.1016\/S1473-3099(17)30252-9"},{"key":"e_1_2_5_6_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.vaccine.2013.09.071"},{"key":"e_1_2_5_7_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.vaccine.2017.04.045"},{"key":"e_1_2_5_8_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jpeds.2014.01.037"},{"key":"e_1_2_5_9_1","doi-asserted-by":"publisher","DOI":"10.1093\/cid\/ciw290"},{"key":"e_1_2_5_10_1","doi-asserted-by":"publisher","DOI":"10.2105\/AJPH.2011.300606"},{"key":"e_1_2_5_11_1","doi-asserted-by":"publisher","DOI":"10.1503\/cmaj.110754"},{"key":"e_1_2_5_12_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.vaccine.2017.01.075"},{"key":"e_1_2_5_13_1","doi-asserted-by":"publisher","DOI":"10.1002\/ijgo.12341"},{"key":"e_1_2_5_14_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.vaccine.2016.06.054"},{"key":"e_1_2_5_15_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.vaccine.2016.06.078"},{"key":"e_1_2_5_16_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ajog.2011.06.047"},{"key":"e_1_2_5_17_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.vaccine.2017.06.069"},{"key":"e_1_2_5_18_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1471-0528.2002.01068.x"},{"key":"e_1_2_5_19_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-3016.2007.00862.x"},{"key":"e_1_2_5_20_1","doi-asserted-by":"publisher","DOI":"10.1097\/00001648-199509000-00012"},{"key":"e_1_2_5_21_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-3016.2007.00865.x"},{"key":"e_1_2_5_22_1","doi-asserted-by":"publisher","DOI":"10.1067\/mob.2002.127601"},{"key":"e_1_2_5_23_1","doi-asserted-by":"publisher","DOI":"10.1067\/mob.2002.120487"},{"key":"e_1_2_5_24_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.vaccine.2015.07.112"},{"key":"e_1_2_5_25_1","doi-asserted-by":"publisher","DOI":"10.1097\/EDE.0b013e3181debe5e"},{"key":"e_1_2_5_26_1","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0092074"},{"key":"e_1_2_5_27_1","doi-asserted-by":"publisher","DOI":"10.1093\/aje\/kww044"},{"key":"e_1_2_5_28_1","doi-asserted-by":"publisher","DOI":"10.1093\/aje\/kww048"},{"key":"e_1_2_5_29_1","doi-asserted-by":"publisher","DOI":"10.1093\/aje\/kww042"},{"key":"e_1_2_5_30_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.vaccine.2015.08.041"},{"key":"e_1_2_5_31_1","doi-asserted-by":"publisher","DOI":"10.1093\/aje\/kww043"},{"key":"e_1_2_5_32_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0022-3476(05)82056-6"},{"key":"e_1_2_5_33_1","doi-asserted-by":"publisher","DOI":"10.1542\/peds.108.2.e35"},{"key":"e_1_2_5_34_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(14)60932-6"},{"key":"e_1_2_5_35_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(11)60364-4"},{"key":"e_1_2_5_36_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1750-2659.2012.00394.x"},{"key":"e_1_2_5_37_1","volume-title":"R: A Language and Environment for Statistical Computing [Computer Program]","author":"R Foundation for Statistical Computing","year":"2016"},{"key":"e_1_2_5_38_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.0001-6349.2004.00193.x"},{"key":"e_1_2_5_39_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.13448"},{"key":"e_1_2_5_40_1","unstructured":"The American College of Obstetricians and Gynecologists.Methods for estimating the due date.2017."},{"key":"e_1_2_5_41_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0022-3476(99)70015-6"},{"key":"e_1_2_5_42_1","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0124286"},{"key":"e_1_2_5_43_1","doi-asserted-by":"publisher","DOI":"10.1179\/146532810X12786388978526"},{"issue":"4","key":"e_1_2_5_44_1","first-page":"523","article-title":"Estimation of gestational age, using neonatal anthropometry: a cross\u2010sectional study in India","volume":"31","author":"Thawani R","year":"2013","journal-title":"J Health Popul Nutr"},{"key":"e_1_2_5_45_1","doi-asserted-by":"publisher","DOI":"10.1016\/S2214-109X(13)70006-8"},{"key":"e_1_2_5_46_1","doi-asserted-by":"publisher","DOI":"10.1016\/0002-9378(89)90497-3"},{"key":"e_1_2_5_47_1","doi-asserted-by":"publisher","DOI":"10.1001\/jamapediatrics.2015.1438"}],"container-title":["Influenza and Other Respiratory Viruses"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1111%2Firv.12673","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1111\/irv.12673","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/full-xml\/10.1111\/irv.12673","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1111\/irv.12673","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,9,9]],"date-time":"2023-09-09T02:23:07Z","timestamp":1694226187000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1111\/irv.12673"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,8,19]]},"references-count":46,"journal-issue":{"issue":"6","published-print":{"date-parts":[[2019,11]]}},"alternative-id":["10.1111\/irv.12673"],"URL":"https:\/\/doi.org\/10.1111\/irv.12673","archive":["Portico"],"relation":{},"ISSN":["1750-2640","1750-2659"],"issn-type":[{"value":"1750-2640","type":"print"},{"value":"1750-2659","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,8,19]]},"assertion":[{"value":"2018-06-19","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2019-07-23","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2019-08-19","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}