ArticleCMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne2021
Maternal cardiovascular disease after twin pregnancies complicated by hypertensive disorders of pregnancy: a population-based cohort study.
Article in CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 9 papers, 1 of them a synthesis that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
9 citing papers in PubMed, 1 synthesis or guideline pooled it, 18 citations in OpenAlex.
- Association between multiple pregnancy with peripartum cardiomyopathy: a systematic review and meta-analysis.BMC cardiovascular disorders · 2025Pooled it
- Influence of Enhanced Administrative Case-Finding Strategies on Prevalence of Hypertensive Disorders of Pregnancy in Ontario: A Population-Based Descriptive Study.Journal of the American Heart Association · 2026Article
- Longitudinal maternal hemodynamics from late pregnancy to postpartum in uncomplicated twin pregnancies-A glimpse into long-term cardiovascular risk?Acta obstetricia et gynecologica Scandinavica · 2026Article
- Hospitalization for cardiovascular disease in the year after delivery of twin pregnancies.European heart journal · 2025Article
- History of multifetal gestation and long-term maternal mortality.Paediatric and perinatal epidemiology · 2024Article
- Association of adverse pregnancy outcomes and multiple gestation with natural menopause: A population-based cohort study.Maturitas · 2023Article
- Coronary Artery Restenosis in Women by History of Preeclampsia.Journal of the American Heart Association · 2022Article
- Defective Uteroplacental Vascular Remodeling in Preeclampsia: Key Molecular Factors Leading to Long Term Cardiovascular Disease.International journal of molecular sciences · 2021Review
- Assisted human reproduction and pregnancy outcomes in Alberta, 2009-2018: a population-based study.CMAJ openArticle
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
12 authors at 4 institutions in 3 countries.
Funding
Abstract
backgroundPeople whose singleton pregnancy is affected by hypertensive disorders of pregnancy (HDP) are at risk of future cardiovascular disease. It is unclear, however, whether this association can be extrapolated to twin pregnancies. We aimed to compare the association between HDP and future cardiovascular disease after twin and singleton pregnancies.
methodsWe conducted a population-based retrospective cohort study that included nulliparous people in Ontario, Canada, 1992-2017. We compared the future risk of cardiovascular disease among pregnant people from the following 4 groups: those who delivered a singleton without HDP (referent) and with HDP, and those who delivered twins either with or without HDP.
resultsThe populations of the 4 groups were as follows: 1 431 651 pregnant people in the singleton birth without HDP group; 98 631 singleton birth with HDP; 21 046 twin birth without HDP; and 4283 twin birth with HDP. The median duration of follow-up was 13 (interquartile range 7-20) years. The incidence rate of cardiovascular disease was lowest among those with a singleton or twin birth without HDP (0.72 and 0.74 per 1000 person-years, respectively). Compared with people with a singleton birth without HDP, the risk of cardiovascular disease was highest among those with a singleton birth and HDP (1.47 per 1000 person-years; adjusted hazard ratio [HR] 1.81 [95% confidence interval (CI) 1.72-1.90]), followed by people with a twin pregnancy and HDP (1.07 per 1000 person-years; adjusted HR 1.36 [95% CI 1.04-1.77]). The risk of the primary outcome after a twin pregnancy with HDP was lower than that after a singleton pregnancy with HDP (adjusted HR 0.74 [95% CI 0.57-0.97]), when compared directly.
interpretationIn a twin pregnancy, HDP are weaker risk factors for postpartum cardiovascular disease than in a singleton pregnancy.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.