Interpregnancy intervals and adverse birth outcomes in high-income countries: An international cohort study.
<h4>Background</h4>Most evidence for interpregnancy interval (IPI) and adverse birth outcomes come from studies that are prone to incomplete control for confounders that vary between women. Comparing pregnancies to the same women can address this issue.<h4>Methods</h4>We cond...
| Main Authors: | , , , , , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2021-01-01
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| Series: | PLoS ONE |
| Online Access: | https://doi.org/10.1371/journal.pone.0255000 |
| _version_ | 1818851901385474048 |
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| author | 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 |
| author_facet | 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 |
| author_sort | Gizachew A Tessema |
| collection | DOAJ |
| description | <h4>Background</h4>Most evidence for interpregnancy interval (IPI) and adverse birth outcomes come from studies that are prone to incomplete control for confounders that vary between women. Comparing pregnancies to the same women can address this issue.<h4>Methods</h4>We conducted an international longitudinal cohort study of 5,521,211 births to 3,849,193 women from Australia (1980-2016), Finland (1987-2017), Norway (1980-2016) and the United States (California) (1991-2012). IPI was calculated based on the time difference between two dates-the date of birth of the first pregnancy and the date of conception of the next (index) pregnancy. We estimated associations between IPI and preterm birth (PTB), spontaneous PTB, and small-for-gestational age births (SGA) using logistic regression (between-women analyses). We also used conditional logistic regression comparing IPIs and birth outcomes in the same women (within-women analyses). Random effects meta-analysis was used to calculate pooled adjusted odds ratios (aOR).<h4>Results</h4>Compared to an IPI of 18-23 months, there was insufficient evidence for an association between IPI <6 months and overall PTB (aOR 1.08, 95% CI 0.99-1.18) and SGA (aOR 0.99, 95% CI 0.81-1.19), but increased odds of spontaneous PTB (aOR 1.38, 95% CI 1.21-1.57) in the within-women analysis. We observed elevated odds of all birth outcomes associated with IPI ≥60 months. In comparison, between-women analyses showed elevated odds of adverse birth outcomes for <12 month and >24 month IPIs.<h4>Conclusions</h4>We found consistently elevated odds of adverse birth outcomes following long IPIs. IPI shorter than 6 months were associated with elevated risk of spontaneous PTB, but there was insufficient evidence for increased risk of other adverse birth outcomes. Current recommendations of waiting at least 24 months to conceive after a previous pregnancy, may be unnecessarily long in high-income countries. |
| first_indexed | 2024-12-19T07:12:23Z |
| format | Article |
| id | doaj.art-5a06ca8363124014bec183d4d1f7e992 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-19T07:12:23Z |
| publishDate | 2021-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-5a06ca8363124014bec183d4d1f7e9922022-12-21T20:31:09ZengPublic Library of Science (PLoS)PLoS ONE1932-62032021-01-01167e025500010.1371/journal.pone.0255000Interpregnancy intervals and adverse birth outcomes in high-income countries: An international cohort study.Gizachew A TessemaM Luke MarinovichSiri E HåbergMika GisslerJonathan A MayoNatasha NassarStephen BallAna Pilar BetránAmanuel T GebremedhinNick de KlerkMaria C MagnusCicely MarstonAnnette K ReganGary M ShawAmy M PadulaGavin Pereira<h4>Background</h4>Most evidence for interpregnancy interval (IPI) and adverse birth outcomes come from studies that are prone to incomplete control for confounders that vary between women. Comparing pregnancies to the same women can address this issue.<h4>Methods</h4>We conducted an international longitudinal cohort study of 5,521,211 births to 3,849,193 women from Australia (1980-2016), Finland (1987-2017), Norway (1980-2016) and the United States (California) (1991-2012). IPI was calculated based on the time difference between two dates-the date of birth of the first pregnancy and the date of conception of the next (index) pregnancy. We estimated associations between IPI and preterm birth (PTB), spontaneous PTB, and small-for-gestational age births (SGA) using logistic regression (between-women analyses). We also used conditional logistic regression comparing IPIs and birth outcomes in the same women (within-women analyses). Random effects meta-analysis was used to calculate pooled adjusted odds ratios (aOR).<h4>Results</h4>Compared to an IPI of 18-23 months, there was insufficient evidence for an association between IPI <6 months and overall PTB (aOR 1.08, 95% CI 0.99-1.18) and SGA (aOR 0.99, 95% CI 0.81-1.19), but increased odds of spontaneous PTB (aOR 1.38, 95% CI 1.21-1.57) in the within-women analysis. We observed elevated odds of all birth outcomes associated with IPI ≥60 months. In comparison, between-women analyses showed elevated odds of adverse birth outcomes for <12 month and >24 month IPIs.<h4>Conclusions</h4>We found consistently elevated odds of adverse birth outcomes following long IPIs. IPI shorter than 6 months were associated with elevated risk of spontaneous PTB, but there was insufficient evidence for increased risk of other adverse birth outcomes. Current recommendations of waiting at least 24 months to conceive after a previous pregnancy, may be unnecessarily long in high-income countries.https://doi.org/10.1371/journal.pone.0255000 |
| spellingShingle | 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 Interpregnancy intervals and adverse birth outcomes in high-income countries: An international cohort study. PLoS ONE |
| title | Interpregnancy intervals and adverse birth outcomes in high-income countries: An international cohort study. |
| title_full | Interpregnancy intervals and adverse birth outcomes in high-income countries: An international cohort study. |
| title_fullStr | Interpregnancy intervals and adverse birth outcomes in high-income countries: An international cohort study. |
| title_full_unstemmed | Interpregnancy intervals and adverse birth outcomes in high-income countries: An international cohort study. |
| title_short | Interpregnancy intervals and adverse birth outcomes in high-income countries: An international cohort study. |
| title_sort | interpregnancy intervals and adverse birth outcomes in high income countries an international cohort study |
| url | https://doi.org/10.1371/journal.pone.0255000 |
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