Public Release: 

Beta blockers safe for use in early pregnancy

American College of Physicians

Below please find summaries of new articles that will be published in the next issue of Annals of Internal Medicine. The summaries are not intended to substitute for the full articles as a source of information.

1. Beta blockers safe for use in early pregnancy
The antihypertensives are not associated with a significant risk for birth defects

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Beta-blockers used in the first trimester of pregnancy are not associated with a large increase in the risk for cardiac or other general birth defects. Findings from an international cohort study are published in Annals of Internal Medicine.

Chronic hypertension is increasingly prevalent in pregnancy and up to 1 percent of pregnancies in are exposed to beta blockers during the first trimester in the United States. Because beta-blockers cross the placenta, there is concern that they could have a negative effect on the unborn fetus.

Researchers from Brigham and Women's Hospital and Harvard Medical School studied health records for 3.6 million pregnancies drawn from the registries of the five Nordic countries and the MAX (2000-to-2010 Medicaid Analytic eXtract) data set in the United States to estimate the risk for major congenital malformations associated with first-trimester exposure to beta-blockers. They found that the excess risk per 1000 persons exposed to beta-blockers in the first trimester of no more than 12.6 for congenital malformations overall, 8.4 for cardiac malformations, 3.0 for cleft lip or palate, and 4.0 for CNS malformations after adjustment for confounding factors, including maternal hypertension. The risk estimates were generally consistent in the Nordic and U.S. data.

According to the author of an accompanying editorial from the University of Toronto, fetal well-being depends on maternal well-being, and untreated maternal disease both jeopardizes the health of the fetus and may shorten pregnancy. The author confirms that beta-blockers should be used in pregnancy when indicated.

Media contact: For an embargoed PDF, please contact Lauren Evans at To interview the lead author, Brian T. Bateman, MD, MSc, please contact Elaine St. Peter at

2. Replacement of recipient hematopoietic cells with donor cells may be a major factor in HIV remission after allo-HSCT
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Radical reductions in HIV-infected cells, and even cure, have been noted following allogeneic hematopoietic stem cell transplantations (allo-HST). The mechanisms determining why some, but not all, HSCT recipients achieve such favourable results have not been clear. Replacement of recipienthematopoietic cells with donor cells, the source of the stem cells used in the transplant and a graft-versus-host effect may be major factors in achieving profound long-term reductions in the HIV reservoir after allo-HST. Findings are published in Annals of Internal Medicine.

Combination antiretroviral therapy (cART) is unable to eliminate HIV infection despite effective viremic control. Allo-HSCT has contributed to the only known case of complete HIV eradication (the "Berlin patient"), but the underlying biological mechanisms are not fully understood. The IciStem consortium was constituted in 2014 with funding from The Foundation for AIDS Research, amfAR, to study these mechanisms.

Researchers from the IrsiCaixa AIDS Research Institute in Barcelona, Spain studied six HIV-infected, ART-treated participants who survived more than 2 years after allo-HSCT with CCR4 wild-type donor cells to investigate the mechanism of HIV-1 eradication. Five of them had undetectable reservoir in blood and tissues. The only participant with a detectable HIV reservoir received a cord blood transplant, did not develop graft-versus-host-disease and had mixed chimera in T cells up to post-transplant month 18. In one of the participants, viral antibodies were not detected after 7 years post-transplant, suggesting that he experienced seroreversion. These results suggest that such factors as stem cell source, conditioning, and possible "graft-versus-HIV-reservoir" effect may have contributed.

According to the authors, understanding the mechanisms involved in HIV eradication after allo-HSCT can enable the design of new curative strategies.

Media contact: For an embargoed PDF, please contact Lauren Evans at To interview the lead author, Javier Martinez-Picado, PhD, please contact Júlia Bestard at

3. ICU admissions among Medicare beneficiaries on a decade-long downward trend
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Admission rates to the intensive care unit (ICU) among Medicare fee-for-service beneficiaries in the United States have been declining over the past 10 years, with large variations by state. Findings from a brief research report are published in Annals of Internal Medicine.

Researchers from the University of Pennsylvania used the entire Medicare Provider Analysis and Review file to evaluate all hospitalizations involving acute and ICU care between 2006 and 2015 among Medicare fee-for-service beneficiaries aged 65 years or older to evaluate geographic differences in admission incidence. They found that as a whole, ICU admission rates have declined over the past decade, but rates varied greatly between states. The heterogeneity in admission rates across states was only partially associated with ICU bed availability, whereas temporal changes in admission rates were not associated with bed growth.

According to the authors, future research should focus on more local and granular data to identify factors associated with underlying regional differences in ICU admission patterns.

Media contact: For an embargoed PDF, please contact Lauren Evans at To interview the lead author, Gary E. Weissman, MD, MSHP, please contact Katie Delach at


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