{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,12]],"date-time":"2026-06-12T04:59:20Z","timestamp":1781240360682,"version":"3.54.1"},"reference-count":29,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,6,12]],"date-time":"2026-06-12T00:00:00Z","timestamp":1781222400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Endocrinol."],"abstract":"<jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>To investigate whether pre-pregnancy body mass index (BMI) modifies the association between interpregnancy interval (IPI) and preterm birth (PTB) risk and to determine the BMI-specific IPI associated with the lowest PTB risk.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>This population-based retrospective cohort study utilized data from 127,542 multiparous women in Dongguan, China (2014-2024). We employed two complementary approaches: a generalized additive mixed model and generalized estimating equations with restricted cubic splines, to examine the interaction between IPI and pre-pregnancy BMI on PTB. The robustness of the findings was evaluated through inverse probability weighting and subgroup analyses.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Pre-pregnancy BMI significantly modified the IPI-PTB association. A clear inverse relationship was observed, whereby the IPI associated with the lowest PTB risk shortened progressively as BMI increased. The adjusted IPI associated with the lowest PTB risk decreased from 38.8 months (95% CI: 32.0-60.0) among underweight women to 32.4 months (29.7-37.2) for normal weight and 26.7 months (6.0-30.8) for overweight. For women with obesity, within the studied range (IPI \u2265 6 months), the lowest risk was observed at the shortest interval (6.0 months), although the wide 95% confidence interval (6.0-60.0) and the exclusion of IPIs\n                      <jats:bold>&amp;lt;<\/jats:bold>\n                      6 months warrant cautious interpretation. This\n                      <jats:bold>\u201c<\/jats:bold>\n                      dose-response\n                      <jats:bold>\u201d<\/jats:bold>\n                      pattern remained robust across sensitivity and subgroup analyses.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>This study provides evidence that pre-pregnancy BMI is an important effect modifier of the IPI-PTB relationship. The finding that the IPI associated with the lowest PTB risk shortens with increasing BMI indicates that the relationship between interpregnancy interval and preterm birth varies by maternal BMI. Although causal inference cannot be drawn from this observational study, the results suggest that uniform IPI guidelines may warrant re-examination across BMI categories.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fendo.2026.1762209","type":"journal-article","created":{"date-parts":[[2026,6,12]],"date-time":"2026-06-12T04:42:49Z","timestamp":1781239369000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Pre-pregnancy BMI modifies the optimal interpregnancy interval for preventing preterm birth: a population-based retrospective cohort study"],"prefix":"10.3389","volume":"17","author":[{"given":"Min-Yi","family":"Yuan","sequence":"first","affiliation":[{"name":"Dongguan Maternal and Child Health Care Hospital","place":["Dongguan, Guangdong, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Si-Liang","family":"Zeng","sequence":"additional","affiliation":[{"name":"Dongguan Maternal and Child Health Care Hospital","place":["Dongguan, Guangdong, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wei-Chao","family":"He","sequence":"additional","affiliation":[{"name":"Dongguan Maternal and Child Health Care Hospital","place":["Dongguan, Guangdong, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,6,12]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"B2","DOI":"10.1016\/j.ajog.2022.02.021","article-title":"Society for Maternal-Fetal Medicine Special Statement: Quality metrics for optimal timing of antenatal corticosteroid administration","volume":"226","author":"Hamm","year":"2022","journal-title":"Am J Obstet Gynecol"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.1016\/j.lana.2024.100687","article-title":"Association of interpregnancy interval with adverse pregnancy outcomes according to the outcomes of the preceding pregnancy: a longitudinal study with 4.7 million live births from Brazil","volume":"30","author":"Tedde","year":"2024","journal-title":"Lancet Reg Health Am"},{"key":"B3","doi-asserted-by":"publisher","first-page":"331 e331","DOI":"10.1016\/j.ajog.2021.05.013","article-title":"Long and short interpregnancy intervals increase severe maternal morbidity","volume":"225","author":"Garg","year":"2021","journal-title":"Am J Obstet Gynecol"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.1007\/s12519-023-00728-4","article-title":"Interactions between long interpregnancy interval and advanced maternal age on neonatal outcomes","volume":"19","author":"Ma","year":"2023","journal-title":"World J Pediatr"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.1002\/uog.29170","article-title":"Association of maternal body mass index with hemodynamic and vascular alterations at 35-37 weeks' gestation","volume":"65","author":"Charakida","year":"2025","journal-title":"Ultrasound Obstet Gynecol"},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.1093\/ajcn\/nqab416","article-title":"Associations of maternal birth weight, childhood height, BMI, and change in height and BMI from childhood to pregnancy with risks of preterm delivery","volume":"115","author":"Pedersen","year":"2022","journal-title":"Am J Clin Nutr"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.1161\/circresaha.123.322762","article-title":"Body mass index, adverse pregnancy outcomes, and cardiovascular disease risk","volume":"133","author":"Khan","year":"2023","journal-title":"Circ Res"},{"key":"B8","doi-asserted-by":"publisher","DOI":"10.1016\/j.bbcan.2023.189000","article-title":"The interplay of obesity, microbiome dynamics, and innovative anti-obesity strategies in the context of endometrial cancer progression and therapeutic approaches","volume":"1878","author":"Burkett","year":"2023","journal-title":"Biochim Biophys Acta Rev Cancer"},{"key":"B9","doi-asserted-by":"publisher","DOI":"10.1037\/met0000444","article-title":"Space-time modeling of intensive binary time series eye-tracking data using a generalized additive logistic regression model","volume":"27","author":"Cho","year":"2022","journal-title":"Psychol Methods"},{"key":"B10","doi-asserted-by":"publisher","first-page":"117891","DOI":"10.2139\/ssrn.4965120","article-title":"The effect of PM(2.5) exposure on placenta and its associated metabolites: A birth cohort study","volume":"292","author":"Wang","year":"2025","journal-title":"Ecotoxicol Environ Saf"},{"key":"B11","doi-asserted-by":"publisher","DOI":"10.1177\/0962280210395740","article-title":"Review of inverse probability weighting for dealing with missing data","volume":"22","author":"Seaman","year":"2013","journal-title":"Stat Methods Med Res"},{"key":"B12","doi-asserted-by":"publisher","DOI":"10.1016\/j.envres.2024.119276","article-title":"Maternal pre-pregnancy BMI influences the associations between bisphenol and phthalate exposures and maternal weight changes and fat accumulation","volume":"257","author":"Irvine","year":"2024","journal-title":"Environ Res"},{"key":"B13","doi-asserted-by":"publisher","first-page":"61","DOI":"10.1186\/s12966-022-01298-w","article-title":"Associations of ultra-processed food intake with maternal weight change and cardiometabolic health and infant growth","volume":"19","author":"Cummings","year":"2022","journal-title":"Int J Behav Nutr Phys Act"},{"key":"B14","doi-asserted-by":"publisher","DOI":"10.3390\/biomedicines12122801","article-title":"The interplay of uterine health and obesity: A comprehensive review","volume":"12","author":"\u0160i\u0161ljagi\u0107","year":"2024","journal-title":"Biomedicines"},{"key":"B15","doi-asserted-by":"publisher","first-page":"101","DOI":"10.1186\/s12933-024-02184-4","article-title":"Postpartum weight retention and the early evolution of cardiovascular risk over the first 5 years after pregnancy","volume":"23","author":"Kramer","year":"2024","journal-title":"Cardiovasc Diabetol"},{"key":"B16","doi-asserted-by":"publisher","DOI":"10.1530\/rep-24-0464","article-title":"Impacts of maternal excess adiposity on the uterine immune environment: contributions to placental dysfunction and adverse pregnancy outcomes","volume":"170","author":"Bellissimo","year":"2025","journal-title":"Reproduction"},{"key":"B17","doi-asserted-by":"publisher","first-page":"71","DOI":"10.1530\/joe-20-0446","article-title":"Obesity is associated with heavy menstruation that may be due to delayed endometrial repair","volume":"249","author":"Reavey","year":"2021","journal-title":"J Endocrinol"},{"key":"B18","doi-asserted-by":"publisher","DOI":"10.1111\/obr.13567","article-title":"Maternal obesity and offspring health: Adapting metabolic changes through autophagy and mitophagy","volume":"24","author":"Wang","year":"2023","journal-title":"Obes Rev"},{"key":"B19","doi-asserted-by":"publisher","DOI":"10.1093\/ajcn\/nqaa436","article-title":"Short interpregnancy intervals and risks for birth defects: support for the nutritional depletion hypothesis","volume":"113","author":"Petersen","year":"2021","journal-title":"Am J Clin Nutr"},{"key":"B20","doi-asserted-by":"publisher","DOI":"10.1016\/j.blre.2023.101159","article-title":"Iron deficiency anemia among women: An issue of health equity","volume":"64","author":"Tang","year":"2024","journal-title":"Blood Rev"},{"key":"B21","doi-asserted-by":"publisher","DOI":"10.1016\/j.neubiorev.2023.105512","article-title":"Methyl\u00a0donor micronutrients, hypothalamic development and programming for metabolic disease","volume":"157","author":"Kubant","year":"2024","journal-title":"Neurosci Biobehav Rev"},{"key":"B22","doi-asserted-by":"publisher","first-page":"397","DOI":"10.1177\/17474930231212972","article-title":"Effect of abnormal body weight on mortality and functional recovery in adults after stroke: An umbrella review","volume":"19","author":"Holland","year":"2024","journal-title":"Int J Stroke"},{"key":"B23","doi-asserted-by":"publisher","DOI":"10.1016\/j.fertnstert.2022.07.027","article-title":"Nutrition recommendations for a healthy pregnancy and lactation in women with overweight and obesity-strategies for weight loss before and after pregnancy","volume":"118","author":"Hart","year":"2022","journal-title":"Fertil Steril"},{"key":"B24","doi-asserted-by":"publisher","DOI":"10.1016\/j.eclinm.2025.103071","article-title":"Inter-pregnancy interval and uterine rupture during a trial of labour after one previous caesarean delivery and no previous vaginal births: a retrospective population-based cohort study","volume":"80","author":"Adily","year":"2025","journal-title":"EClinicalMedicine"},{"key":"B25","doi-asserted-by":"publisher","DOI":"10.1007\/s10995-016-2140-8","article-title":"Racial differences in the influence of interpregnancy interval on fetal growth","volume":"21","author":"Atreya","year":"2017","journal-title":"Matern Child Health J"},{"key":"B26","doi-asserted-by":"publisher","DOI":"10.1001\/jamanetworkopen.2022.16658","article-title":"Association of interpregnancy interval with adverse birth outcomes","volume":"5","author":"Xu","year":"2022","journal-title":"JAMA Netw Open"},{"key":"B27","doi-asserted-by":"publisher","DOI":"10.1001\/jama.2021.6949","article-title":"Behavioral counseling interventions for healthy weight and weight gain in pregnancy: US preventive services task force recommendation statement","volume":"325","author":"Davidson","year":"2021","journal-title":"JAMA"},{"key":"B28","doi-asserted-by":"publisher","DOI":"10.1097\/aog.0000000000001891","article-title":"Interpregnancy interval and adverse pregnancy outcomes: an analysis of successive pregnancies","volume":"129","author":"Hanley","year":"2017","journal-title":"Obstet Gynecol"},{"key":"B29","doi-asserted-by":"publisher","DOI":"10.1055\/s-0038-1673395","article-title":"The association between maternal height, body mass index, and perinatal outcomes","volume":"36","author":"Marshall","year":"2019","journal-title":"Am J Perinatol"}],"container-title":["Frontiers in Endocrinology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fendo.2026.1762209\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,6,12]],"date-time":"2026-06-12T04:43:03Z","timestamp":1781239383000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fendo.2026.1762209\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,6,12]]},"references-count":29,"alternative-id":["10.3389\/fendo.2026.1762209"],"URL":"https:\/\/doi.org\/10.3389\/fendo.2026.1762209","relation":{},"ISSN":["1664-2392"],"issn-type":[{"value":"1664-2392","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,6,12]]},"article-number":"1762209"}}