News Release

No link found between maternal flu vaccination during pregnancy and autism

Embargoed news from Annals of Internal Medicine

Peer-Reviewed Publication

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. This information is under strict embargo and by taking it into possession, media representatives are committing to the terms of the embargo not only on their own behalf, but also on behalf of the organization they represent.

1. No link found between maternal flu vaccination during pregnancy and autism
Another study shows that vaccines during pregnancy are safe

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A large cohort study found no association between maternal H1N1 vaccination during pregnancy and risk for autism spectrum disorder (ASD) in children. Furthermore, no association was found for vaccine exposure in the first trimester and ASD or the secondary outcome, autistic disorder (AD). The findings are published in Annals of Internal Medicine.

Although some studies indicate that influenza vaccination during pregnancy protects against morbidity in both the woman and her offspring, the long-term risks of H1N1 vaccination exposure during fetal life have not been examined in detail. A recent U.S. study found a small increased risk for ASD in offspring of women who received influenza vaccination during the first trimester. The proportion of H1N1 vaccine and associated risks were not reported.

Researchers from Karolinska Institute, Stockholm, Sweden, studied live birth records between October 2009 and September 2010 with follow-up through December 2016 to examine the risk for ASD in mothers who were vaccinated against influenza A (H1N1) during pregnancy. In total, 39,726 infants were prenatally exposed to the vaccine (13,845 during the first trimester), and 29,293 were unexposed. After a mean follow-up of 6.7 years, the researchers found that ASD and AD cases were virtually the same between vaccine-exposed and unexposed children. Restricting the analysis to vaccination in the first trimester of pregnancy did not influence risk estimates for ASD or AD. According to the researchers, these findings suggest that vaccination strategies focusing on pregnant women are safe.

Media contacts: For an embargoed PDF, please contact Lauren Evans at The corresponding author, Jonas F. Ludvigsson, can be contacted through the press office at

2. Reported cannabis use on the rise among older adults
Men were twice as likely as women to report use in the past 30 days

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A survey of U.S. adults found that reported cannabis use is on the rise among older men and women, and especially in men. While the data showed increased use in states that had passed laws to allow medicinal or other types of use (as well as states not permitting such use), the authors urge caution because there was limited data from a state level. A brief research report is published in Annals of Internal Medicine.

Researchers from the University of Massachusetts Medical School and University of Waterloo, Waterloo, Ontario, Canada, studied data for 2016 to 2018 from the Behavioral Risk Factor Surveillance System, a random-digit-dial telephone survey with results that are generalizable to the U.S. population, to describe recent trends in cannabis use among older Americans, overall and by age, sex, and state legalization status. The survey asked, "During the past 30 days, on how many days did you use marijuana or hashish?" They found that the average prevalence of cannabis use for all respondents (aged 55+ years) in all years was 4.9 percent, with the proportion of men reporting use twice as high as that for women. Use decreased with age and was generally higher in states where recreational cannabis was legal.

The authors advise health care providers to be attentive to the potential for cannabis use in older adults. They also encourage increased pharmacoepidemiologic and clinical trials of cannabis use in this rapidly growing segment of the population.

Media contacts: For an embargoed PDF, please contact Lauren Evans at The corresponding author, Colleen J. Maxwell, PhD, can be contacted directly at

3. Artificial intelligence predicts 12-year risk for lung cancer from a person's chest x-ray

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A deep learning model, a form of artificial intelligence (AI), was more accurate than the current clinical standard at predicting a person's 12-year risk of developing lung cancer. The model's predictions are based on chest radiograph images (CXRs) and basic demographic data (age, sex, and current smoking status) commonly available in electronic health records (EHRs). The findings are published in Annals of Internal Medicine.

Lung cancer screening with chest computed tomography (CT) scans can prevent lung cancer death. However, Medicare's current standard to determine who is eligible for lung cancer screening CT misses most lung cancers. Furthermore, lung cancer screening participation is poor, with an estimated less than 5 percent of screening-eligible persons being screened.

Researchers from Massachusetts General Hospital developed a convolutional neural network (CXR-LC) that predicts long-term incident lung cancer based on a chest x-ray image using 41,856 people from a large multicenter trial of lung cancer screening with chest x-rays (Prostate, Lung, Colorectal, and Ovarian (PLCO) cancer screening trial). The final model was validated in 5,615 additional PLCO participants and 5,493 persons from a second trial, the National Lung Screening Trial (NLST). The deep learning model performed better than the Medicare lung cancer screening criteria, the current clinical standard, missing 31 percent fewer lung cancers while screening the same number of people.

The author of an accompanying editorial from the National Cancer Institute discusses the researchers' findings and raises a number of issues associated with the use of AI and, more generally, data mining of EHRs to improve patient care.

Media contacts: For an embargoed PDF, please contact Lauren Evans at The corresponding author, Michael T. Lu, MD, MPH, can be reached through Julie Cunningham at JULIE.CUNNINGHAM@MGH.HARVARD.EDU. The editorialist, Paul Pinsky, PhD, can be reached at

4. U.S. VA/DoD guidelines recommend intensive BP lowering in most patients with hypertension to improve cardiovascular outcomes

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The U.S. Department of Veterans Affairs (VA) and the U.S. Department of Defense (DoD) recommend intensive blood pressure (BP) lowering in most patients with hypertension to improve cardiovascular outcomes. A synopsis of the 2020 joint clinical practice guideline for the diagnosis and management of hypertension in the primary care setting is published in Annals of Internal Medicine.

To inform the guidelines, researchers from the independent nonprofit ECRI, working on behalf of the VA, reviewed 8 systematic reviews of randomized controlled trials to summarize the effects of intensive (or targeted) systolic BP or diastolic BP lowering with pharmacologic treatment on cardiovascular outcomes and harms in adults with hypertension. Hypertension was defined as having a systolic BP of 130 mm Hg or greater and a diastolic BP of 80 mm Hg or greater. High-strength evidence showed benefit of intensive BP lowering (a reduction of 10 mm Hg) in patients with hypertension for improving cardiovascular outcomes. In most subpopulations, intensive lowering was favored over less-intensive lowering, but the data were less clear for patients with diabetes or cardiovascular disease.

The patient-centered guideline also recommends periodic screening for elevated BP in adults. For nonpharmacologic BP lowering, the researchers recommend weight loss, exercise, and the Stop Hypertension Diet or a dietician-led Mediterranean diet. Evidence supports the use of a thiazide-type diuretic, a calcium-channel blocker (CCB), or either an angiotensin-converting enzyme inhibitor (ACEI) or an angiotensin II receptor blocker as primary pharmacologic therapy for hypertension. For patients with resistant hypertension (defined as those who are not adequately controlled with maximally tolerated dose of triple therapy [i.e., a thiazide-type diuretic, calcium channel blockers, and angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker]), the guideline suggests adding spironolactone in those patients without contraindications.

Media contacts: For an embargoed PDF, please contact Lauren Evans at To speak with the corresponding author, Kristen E. D'Anci, PhD, please contact Laurie Menyo at

5. Synopsis: ADA issues new guidelines for pharmaceutical management of type 2 diabetes
Early combination therapy now recommended for patients with cardiovascular disease or chronic kidney disease

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The latest clinical guidelines from the American Diabetes Association (ADA) recommends early combination therapy for patients in whom glycemic control is not achieved within 3 months and for those with cardiovascular disease (CVD) or chronic kidney disease (CKD) and type 2 diabetes. Metformin is still the preferred initial pharmacologic agent. A synopsis of the 2020 American Diabetes Association's Standards of Medical Care in Diabetes Clinical Guideline is published in Annals of Internal Medicine.

Authors from Mark's Hospital and St. Mark's Diabetes Center, Salt Lake City, Utah, summarized the guidelines, which were developed by the ADA Professional Practice Committee, comprising physicians, adult and pediatric endocrinologists, diabetes educators, registered dietitians, epidemiologists, pharmacists, and public health experts. The committee selected and reviewed published studies, developed the recommendations, and solicited feedback from the larger clinical community. In summary:

  • Lifestyle changes and metformin are still recommended as first-line treatments;
  • Second-line medication options include SGLT2 inhibitors, GLP-1 RAs, dipeptidyl peptidase-4 (DPP-4) inhibitors, thiazolidinedione, sulfonylureas, and basal insulin;
  • Early combination therapy should be initiated for patients who do not achieve glycemic control within 3 months and/or for those with CVD or CKD;
  • Insulin therapy should be discussed with patients as a way to escalate therapy, rather than as a failure on the patient's part.

The synopsis focuses on pharmacological treatment of type 2 diabetes. The full clinical guidelines can be accessed at

Media contacts: For an embargoed PDF please contact Lauren Evans at The lead author, Kacie Doyle-Delgado, DNP, APRN, can be reached directly at


Also in this issue:

Toward Historical Accountability and Remembrance: The German Society for Internal Medicine and Its Legacies From the Nazi Past

History of Medicine

In the Clinic: Hepatitis C Virus

In the Clinic

Signs You Might Be a Physician Mom

Graphic Medicine

T-regulatory Cells: Treatment for COVID-19?

Annals On Call

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