M L Marinovich1, A K Regan2, M Gissler3,4, M C Magnus5,6, S E Håberg6, J A Mayo7, G M Shaw7, J Bell8, N Nassar8, S Ball9, A T Gebremedhin1, C Marston10, N de Klerk11, A P Betrán12,13, A M Padula13, G Pereira1,6,11. 1. School of Public Health, Curtin University, Perth, WA, Australia. 2. School of Public Health, Texas A&M University, College Station, TX, USA. 3. Information Services Department, Finnish Institute for Health and Welfare, Helsinki, Finland. 4. Department of Neurobiology, Care Sciences and Society, Karolinska Institute, Stockholm, Sweden. 5. MRC Integrative Epidemiology Unit at the University of Bristol, Bristol, UK. 6. Centre for Fertility and Health (CeFH), Norwegian Institute of Public Health, Oslo, Norway. 7. Department of Pediatrics, March of Dimes Prematurity Research Center, Stanford University, Stanford, CA, USA. 8. Children's Hospital at Westmead Clinical School, University of Sydney, Sydney, NSW, Australia. 9. School of Nursing, Midwifery and Paramedicine, Curtin University, Perth, WA, Australia. 10. Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, UK. 11. Telethon Kids Institute, University of Western Australia, Subiaco, WA, Australia. 12. Department of Reproductive Health and Research, UNDP/UNFPA, UNICEF/WHO/World Bank Special Programme of Research, Development and Research Training in Human Reproduction, World Health Organization, Geneva, Switzerland. 13. Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco, CA, USA.
Abstract
OBJECTIVE: To investigate the effect of interpregnancy interval (IPI) on preterm birth (PTB) according to whether the previous birth was preterm or term. DESIGN: Cohort study. SETTING: USA (California), Australia, Finland, Norway (1980-2017). POPULATION: Women who gave birth to first and second (n = 3 213 855) singleton livebirths. METHODS: Odds ratios (ORs) for PTB according to IPIs were modelled using logistic regression with prognostic score stratification for potential confounders. Within-site ORs were pooled by random effects meta-analysis. OUTCOME MEASURE: PTB (gestational age <37 weeks). RESULTS: Absolute risk of PTB for each IPI was 3-6% after a previous term birth and 17-22% after previous PTB. ORs for PTB differed between previous term and preterm births in all countries (P-for-interaction ≤ 0.001). For women with a previous term birth, pooled ORs were increased for IPI <6 months (OR 1.50, 95% CI 1.43-1.58); 6-11 months (OR 1.10, 95% CI 1.04-1.16); 24-59 months (OR 1.16, 95% CI 1.13-1.18); and ≥ 60 months (OR 1.72, 95%CI 1.60-1.86), compared with 18-23 months. For previous PTB, ORs were increased for <6 months (OR 1.30, 95% CI 1.18-1.42) and ≥60 months (OR 1.29, 95% CI 1.17-1.42), but were less than ORs among women with a previous term birth (P < 0.05). CONCLUSIONS: Associations between IPI and PTB are modified by whether or not the previous pregnancy was preterm. ORs for short and long IPIs were higher among women with a previous term birth than a previous PTB, which for short IPI is consistent with the maternal depletion hypothesis. Given the high risk of recurrence and assuming a causal association between IPI and PTB, IPI remains a potentially modifiable risk factor for women with previous PTB. TWEETABLE ABSTRACT: Short versus long interpregnancy intervals associated with higher ORs for preterm birth (PTB) after a previous PTB.
OBJECTIVE: To investigate the effect of interpregnancy interval (IPI) on preterm birth (PTB) according to whether the previous birth was preterm or term. DESIGN: Cohort study. SETTING: USA (California), Australia, Finland, Norway (1980-2017). POPULATION: Women who gave birth to first and second (n = 3 213 855) singleton livebirths. METHODS: Odds ratios (ORs) for PTB according to IPIs were modelled using logistic regression with prognostic score stratification for potential confounders. Within-site ORs were pooled by random effects meta-analysis. OUTCOME MEASURE: PTB (gestational age <37 weeks). RESULTS: Absolute risk of PTB for each IPI was 3-6% after a previous term birth and 17-22% after previous PTB. ORs for PTB differed between previous term and preterm births in all countries (P-for-interaction ≤ 0.001). For women with a previous term birth, pooled ORs were increased for IPI <6 months (OR 1.50, 95% CI 1.43-1.58); 6-11 months (OR 1.10, 95% CI 1.04-1.16); 24-59 months (OR 1.16, 95% CI 1.13-1.18); and ≥ 60 months (OR 1.72, 95%CI 1.60-1.86), compared with 18-23 months. For previous PTB, ORs were increased for <6 months (OR 1.30, 95% CI 1.18-1.42) and ≥60 months (OR 1.29, 95% CI 1.17-1.42), but were less than ORs among women with a previous term birth (P < 0.05). CONCLUSIONS: Associations between IPI and PTB are modified by whether or not the previous pregnancy was preterm. ORs for short and long IPIs were higher among women with a previous term birth than a previous PTB, which for short IPI is consistent with the maternal depletion hypothesis. Given the high risk of recurrence and assuming a causal association between IPI and PTB, IPI remains a potentially modifiable risk factor for women with previous PTB. TWEETABLE ABSTRACT: Short versus long interpregnancy intervals associated with higher ORs for preterm birth (PTB) after a previous PTB.
Authors: Adam Mabrouk; Amina Abubakar; Ezra Kipngetich Too; Esther Chongwo; Ifedayo M Adetifa Journal: Int J Environ Res Public Health Date: 2022-08-24 Impact factor: 4.614
Authors: Gizachew A Tessema; M Luke Marinovich; Siri E Håberg; Mika Gissler; Jonathan A Mayo; Natasha Nassar; Stephen Ball; Ana Pilar Betrán; Amanuel T Gebremedhin; Nick de Klerk; Maria C Magnus; Cicely Marston; Annette K Regan; Gary M Shaw; Amy M Padula; Gavin Pereira Journal: PLoS One Date: 2021-07-19 Impact factor: 3.240