Beets on a Table

Your Mom was Right – Eat your Beets, They’re Good for Your Heart

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By Bianca Garilli, ND

From Metagenics Institute

I have a patient who doesn’t like vegetables. In fact, this person is also not a fan of water (sans flavoring), exercise, nor high fiber foods such as legumes. This scenario is, in many ways, a perfect setup for a number of lifestyle-related chronic diseases, including hypertension. This patient has been on a cocktail of medications for many years but expressed to me that they’d like reduce the list. So, it was with great excitement that I recently shared emerging research on a natural, food-based approach for reducing blood pressure with this individual.

But, first, a little science background. Nitric oxide or NO, is an important signaling molecule in humans and is required for a large number of reactions and biochemical pathways in the body. NO can be made by the body (endogenously) through various, intricate enzymatic pathways and also through non-enzymatic pathways which require precursor nitrates and nitrites.1 One of the best sources of nitrates is the diet; beetroot and leafy greens such as arugula and spinach being some of the highest sources of dietary nitrates.1 After consumption, the dietary nitrate molecules are metabolized by oral bacteria into nitrites which are then endogenously transformed into the cardioprotective NO molecule.2-3

As noted above, NO plays a critical role in cardiovascular health. For example, low levels of NO in the body can lead to various pathologies, most notably endothelial dysfunction which contributes to hypertension and atherosclerosis; low NO has also been found to play a role in diabetes and hypercholesterolemia.1

In contrast, healthy levels of NO in the body support vascular tone, healthy blood flow, leukocyte adhesion, and platelet aggregation.1 Consuming food-based nitrates on a routine basis, then, would seem to be a logical next step for those desiring to prevent or treat NO deficiency-related disease processes. And, in fact, that logic is backed by science, which is the exciting new research I was hoping to share with the unnamed individual mentioned earlier.

A recent study published in Nutrition Reviews presents a systematic review and meta-analysis including 23 studies that measured blood pressure, endothelial function, arterial stiffness, platelet aggregation, and/or blood lipid outcomes in response to oral inorganic nitrate/nitrite intake.4 The analyses demonstrated that inorganic nitrate intake significantly reduced resting blood pressure, improved endothelial function (measured as flow-mediated dilatation), arterial stiffness, and platelet aggregation.4

Many of the studies in this review, utilized beets and beetroot juice as their sources for nitrates in their research. I don’t know about you, but my mother always made sure I ate my beets. These colorful root vegetables have leaves that are also edible and are classified in the Amaranthaceae family, the same family as quinoa, spinach, and lamb’s quarters (AKA wild spinach).5

One of the beetroot studies was a double-blind, placebo-controlled clinical trial that randomized 68 hypertensive individuals 18-85 years of age to one of two groups: 250 mL/day of beetroot juice or the “placebo”250 mL/day of nitrate-free beetroot juice for 4 weeks.6 Participants consumed their respective drinks daily for 4 weeks; this was preceded by a 2-week run-in period followed by a 2-week wash-out period. The trial found that daily supplementation with dietary nitrate from beetroot juice was associated with a reduction in blood pressure: systolic ↓7.7-8.1mmHg; diastolic ↓2.4-5.2mmHg.6 Additionally, endothelial function improved by approximately 20% and there was a reduction in arterial stiffness by 0.59m/s.6

These clinical trial findings are in agreement with a review and meta-analysis7 that analyzed results from multiple studies investigating the therapeutic benefits of beetroot juice supplementation on blood pressure. This review found an overall reduction in systolic and diastolic blood pressure of 3.55 mmHg and 1.32 mmHg, respectively, and these reductions were significantly greater in the beetroot juice supplemented groups vs. control groups.7 This same publication also noted greater improvements in blood pressure with higher (500 mL/day) vs. lower (70-140 mL/day) beetroot juice doses or with longer periods of consumption (≥2 weeks vs. <2 weeks).7

So, as in every good story, there is a moral. First and foremost – listen to your parents. Next, make your plate colorful and eat your vegetables, every day and lots of them. Finally, incorporate beets and other high-nitrate foods such as spinach and arugula into your healthful diet.

Citations

  1. Luiking YC et al. Regulation of nitric oxide production in health and disease. Curr Opin Clin Nutr Metab Care. 2010; 13(1): 97–104.
  2. Hobbs DA et al. Blood pressure-lowering effects of beetroot juice and novel beetroot-enriched bread products in normotensive male subjects. Br J Nutr. 2012;108(11):2066-74.
  3. Khatri J et al. It is rocket science – why dietary nitrate is hard to “beet”! Part I: twists and turns in the realization of the nitrate-nitrite-NO pathway. Br J Clin Pharmacol. 2017;83(1):129–139.
  4. Jackson JK et al. The role of inorganic nitrate and nitrite in cardiovascular disease risk factors: a systematic review and meta-analysis of human evidence. Nutr Rev. 2018;76(5):348-371.
  5. Encyclopedia Brittanica. Amaranthaceae. https://www.britannica.com/plant/Amaranthaceae. Accessed July 26, 2018.
  6. Vikas K et al. Dietary nitrate provides sustained blood pressure lowering in hypertensive patients: a randomized, phase 2, double-blind, placebo-controlled study. Hypertension. 2015;65(2):320–327.
  7. Bahadoran Z et al. The nitrate-independent blood pressure-lowering effect of beetroot juice: a systematic review and meta-analysis. Adv Nutr. 2017;8(6):830-838.

Vitamin D: More Important than Ever

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Vitamin D has always been integral to a healthy diet, but recent evidence suggests it may have a critical role in fighting COVID-19. According to new research, people with low vitamin D levels upon hospital admission for COVID-19 have an almost quadrupled chance of dying.[1]

Vitamin D’s role in fighting COVID-19 is only beginning to be explored, but this vitamin already boasts a host of health benefits. It promotes healthy bone growth and can, according to medical research cited by Harvard University, even reduce cancer cell growth, help fight infections and reduce inflammation.[2]

Do You Get Enough Vitamin D?

So, how can you get enough vitamin D in your diet? Let’s explore options that provide good amounts of this important nutrient.

Fish contain more vitamin D than any other food type, according to the U.S. Food and Drug Administration (FDA).[3] That’s not all, though — fish also are a stellar source of protein, omega-3 fats and multiple minerals. Be careful, however, to follow FDA advisories about fish with high amounts of mercury.

Eggs are another source of vitamin D, according to the Centers for Disease Control and Prevention (CDC).[4] Although they contain less vitamin D than fish, egg yolks nonetheless have a small amount of vitamin D, according to the National Institutes of Health (NIH).[5] Eggs also are a good source of phosphorous, calcium and potassium.[5]

Although fish are among the few foods with a naturally high vitamin D content, other foods and drinks can be enhanced — or, fortified — to contain more vitamin D. Milk, for example, can be fortified with vitamin D. [4] For those avoiding animal products, fortified cereals and juices can provide a good alternative.

While food can provide varying amounts of vitamin D, it’s ultimately difficult to get enough from food alone. In fact, most people should take vitamin D supplements to get enough in their diet, according to Harvard University.[2] Supplements come in many shapes and sizes, so choose wisely!

So, do you get enough vitamin D in your diet? With the rise of COVID-19, it might be more important than ever. Consult with your doctor, maintain a healthy diet and experience the wonders of vitamin D for yourself!

You can order vitamin D through Metagenics, our trusted supplier of nutraceuticals and supplements.

Sources:

  1. https://academic.oup.com/ajcp/advance-article/doi/10.1093/ajcp/aqaa252/6000689
  2. https://www.hsph.harvard.edu/nutritionsource/vitamin-d/
  3. https://www.fda.gov/food/consumers/advice-about-eating-fish
  4. https://www.cdc.gov/nutrition/infantandtoddlernutrition/vitamins-minerals/vitamin-d.html
  5. https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/

Inflammation: The Good, the Bad, & the Ugly

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By Bianca Garilli, ND, IFMCP

Sourced from Metagenics Institute

Too much inflammation can be a bad thing

When the topic of chronic disease comes up, the term inflammation is sure to be close behind. In fact, inflammation has received a fairly bad rap in the past years as research has underscored its prominent role in the promotion and perpetuation of many aspects of physiological dysfunction. Although not the root cause per se, inflammation has been shown to “add fuel to the fire” of a host of disease processes, playing a role in nearly all chronic illnesses.1-4 Here are a few examples where inflammation “feeds the flames” of prevalent diseases:1-4

Timely and balanced inflammation can be a good thing

Interestingly, inflammation is not always a “bad thing” and, when expressed in a timely and correct manner, is an integral part of human health. In fact, appropriate, acute inflammation serves as a first line response to potential pathogens, it limits excessive tissue damage after trauma, and stimulates the body’s inherent repair processes.5

Dolor (pain), calor (heat), rubor (redness), and tumor (swelling) were initially identified in the first century AD by the Roman scholar Celsus as the four classic signs of the inflammatory process.6 A fifth cardinal sign, functio laesa (loss of function), was eventually added and thought to be attributed to Galen, although controversy remains over the original contributor.7

The body is naturally primed to respond to damage or infection through the acute inflammatory reactions of locally occurring cells that produce cytokines and other acute inflammatory mediators. These strategically placed immune cells respond to looming “danger” (infectious agents and trauma) by sending out a series of chemical messages to communicate the problem to various cell types located elsewhere throughout the body. At the same time, other cells are stimulated to release specific substances such as histamine, bradykinin, serotonin, and prostaglandins—each playing a unique role in inflammatory processes, such as the extremely important vasodilation of local blood vessels.8 When “reinforcements” (mainly neutrophils, sometimes eosinophils and others) from various locations answer the chemical signal and arrive to the scene, they are able to migrate directly through the vasodilated capillary walls (diapedesis), making it easier and more expedient for an acute response to occur.9

Healthy, acute inflammation stimulates healing

The benefits of this complex, orchestrated sequence of events is protection and repair to the damaged or infected tissues and can be characterized by the processes of “hemostasis and chemotaxis.”10 These processes reduce the risk of excessive bleeding, further damage, or spread of infection beyond the localized site.10 The acute inflammation stage typically lasts a matter of hours to days.10

In a synchronized dance and while initial steps of acute inflammation are still occurring, additional chemical signals are also being sent out to initiate critical phases of the healing process. The healing process can be characterized by two major phases—the proliferative phase and the maturation-remodeling phase:10

  • The proliferative phase, which can last several weeks, is when granulation tissue is formed, and re-epithelialization and neovascularization occur within the damaged tissues.
  • The maturation-remodeling phase is when strengthening of the scar tissue occurs for maximum impact.

Bacterial infection, an open tissue wound, and blunt trauma are just a few examples where these acute inflammation processes are both critical and beneficial. Acute inflammation plays a major role in human health, essentially discouraging further damage and supporting the healing process. Without an appropriate inflammatory response to infectious agents or trauma, healing is difficult and incomplete.

Resolving prolonged inflammation is critical

Unfortunately, when the inflammatory process goes awry or simply continues too long, this leads to the well-known term, “chronic inflammation,” along with its subsequent downstream chronic illness influences. In some cases, the cells associated with an appropriate inflammatory response fail to return, or resolve, to their pre-inflammation states; in other cases the inflammatory process is heightened and prolonged.11 In both situations there is typically an external stimuli perpetuating the inflammation; this could be a persistent infectious agent, or in other cases, it may involve dietary interactions or toxic exposures. In many cases, the chemical milieu associated with obesity perpetuates the inflammatory molecules, leading to further downstream damage.11-13

Maintaining a healthy and effective inflammatory response

There are two approaches to maintaining a healthy and effective inflammatory response: First, an appropriately timed and placed acute inflammatory process is required in response to infection and trauma and for initiating the healing process. Second, it’s critical that once the benefit of the acute inflammatory response has passed, that the molecular basis of the response returns to its pre-inflammatory state, rather than smoldering into a low-grade chronic inflammation state. This inflammation resolution is an active process facilitated by lipid mediators—specialized pro-resolving mediators (SPMs); this physiological process and the key players were discovered only a couple decades ago by Charles Serhan, PhD, DSc and colleagues.14-16

Here are some specific steps related to lifestyle and personalized nutrition that can be implemented to support a healthy and effective inflammatory response and combat the chronicity of inflammation:16-20

  • Follow an anti-inflammatory dietary approach—variety of whole, minimally processed foods rich in fiber, brightly colored fruits and vegetables high in antioxidants and phytonutrients, and adequate intake of high-quality proteins and healthy fats, especially long-chain omega-3 fatty acids; some food plans avoid or limit gluten, soy, nightshades, dairy products, and sugars.
  • Maintain a healthy weight and support lean and bone mass by participating in routine exercise and
  • Limit exposure to endocrine-disrupting chemicals (EDCs) like obesogens whenever possible
  • Make adequate and high-quality sleep a priority
  • Avoid or limit chronic sources of stress and support healthy stress responses to avoid inflammatory stress molecule production
  • Promote healthy gut barrier function through intake of prebiotics and probiotics
  • Reduce oxidative damage to cells through sufficient or increased intake of antioxidants such as vitamins C, E, and A (beta-carotene) and phytonutrients
  • Consider a personalized supplementation plan with anti-inflammatory actions in the body, such as omega-3s EPA and DHA, curcumin, xanthohumol, Boswellia serrata, ginger, and tetrahydro-iso-alpha acids (THIAA), and CoQ10
  • Consider a personalized supplementation plan that includes targeted nutraceuticals that support the resolution of inflammation, like SPMs, to target unresolved inflammation and turn off the damaging effects of long-term, low-grade chronic inflammatory pathways

Citations

  1. Hunter P. The inflammation theory of disease. The growing realization that chronic inflammation is crucial in many diseases opens new avenues for treatment. EMBO Rep. 2012;13(11):968–970.
  2. Forrester JS et al. Persistence of inflammatory cytokines cause a spectrum of chronic progressive diseases: implications for therapy. Med Hypotheses. 2005;65(2):227-231.
  3. Tsoupras A et al. Inflammation, not cholesterol, is a cause of chronic disease. Nutrients. 2018;10(5):E604.
  4. Felger JC et al. Imaging the role of inflammation in mood and anxiety-related disorders. Curr Neuropharmacol. 2018;16(5):533–558.
  5. Munn LL. Cancer and inflammation. Wiley Interdiscip Rev Syst Biol Med. 2017;9(2).
  6. Ciaccia L et al. Fundamentals of inflammation. Yale J Biol Med. 2011;84(1):64–65.
  7. Rather LJ. Disturbance of function (function laesa): the legendary fifth cardinal sign of inflammation, added by Galen to the four cardinal signs of Celsus. Bull N Y Acad Med. 1971;47(3):303–322.
  8. Medline. Immune response. https://medlineplus.gov/ency/article/000821.htm. Accessed March 29, 2019.
  9. Muller WA. Getting leukocytes to the site of inflammation. Vet Pathol. 2013;50(1):7–22.
  10. Wallace HA et al. Wound Healing Phases. Treasure Island, FL. StatPearls Publishing. 2019. https://www.ncbi.nlm.nih.gov/books/NBK470443/. Accessed March 29, 2019.
  11. Minihane AM et al. Low-grade inflammation, diet composition and health: current research evidence and its translation. Br J Nutr. 2015;114(7):999–1012.
  12. Bischoff SC et al. Intestinal permeability – a new target for disease prevention and therapy. BMC Gastroenterol. 2014;14:189.
  13. Pahwa R et al. Chronic Inflammation. Treasure Island, FL. StatPearls Publishing. 2019. https://www.ncbi.nlm.nih.gov/books/NBK493173/. Accessed April 3, 2019.
  14. Serhan CN et al. Novel functional sets of lipid-derived mediators with antiinflammatory actions generated from omega-3 fatty acids vi cyclooxygenase 2-nonsteroidal antiinflammatory drugs and transcellular processing. J Exp Med. 2000;192(8):1197-1204.
  15. Serhan CN et al. Lipid mediators in the resolution of inflammation. Cold Spring Harb Perspect Biol. 2015;7(2):a016311.
  16. Serhan CN. Pro-resolving lipid mediators in inflammation are leads for resolution physiology. Nature. 2014;510(7503):92–101.
  17. Beavers KM et al. Effect of exercise training on chronic inflammation. Clin Chim Acta. 2010;411(11-12):785–793.
  18. Nappi F et al. Endocrine aspects of environmental “obesogen” pollutants. Int J Environ Res Public Health. 2016;13(8):E765.
  19. Calder PC et al. Inflammatory disease processes and interactions with nutrition. Br J Nutr. 2009;101 Suppl 1:S1-45.
  20. Liu YZ et al. Inflammation: the common pathway of stress-related diseases. Front Hum Neurosci. 2017;11:316.

COVID-19 and Pregnancy: What Do We Know?

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By Michael Stanclift, ND

Sourced from Metagenics Institute


Introduction
Expectant mothers may find some reassurance in recent evidence suggesting COVID-19 infection during pregnancy doesn’t appear to pose the same dangers as related viral infections (e.g. SARS, MERS).1 Pregnant women contracting COVID-19 must still be cautious about their and their developing babies’ health, especially since treatment options are more limited during pregnancy; however, documented cases give us some insight into the short-term effects. As with all things related to COVID-19, the data is still emerging, and we must keep in mind that new information could further support or undermine what we know now. Data on pregnancy is limited by the number of cases and the time frame of the pandemic—meaning we will not know longer range effects or the validity of these findings for some time.

COVID-19-positive pregnant women mostly without symptoms
Doctors in a London hospital during its COVID-19 peak detected coronavirus (SARS-CoV-2) in 7% of pregnant women admitted for delivery; nearly all of them (89%) had no symptoms.2 During the pandemic peak in New York, the positive rate for SARS-CoV-2 in pregnant women was over twice as high as London (15%), with a similar number of them asymptomatic as well.2,3 The authors expressed concern that their findings support a trend of asymptomatic infection in healthcare facilities, suggesting poor infection control.2


What happens when a pregnant woman gets COVID-19
Unlike with infections such as influenza, pregnant women do not appear to be at increased susceptibility for COVID-19 infection, nor do they have more severe disease when they contract it.4 COVID-19 infection in pregnant women presents in much the same way as in nonpregnant patients—usually with a cough, fever, labored breathing, and low lymphocytes.1 Compared to infections caused by similar coronaviruses (SARS/MERS), the death rate in pregnant women with COVID-19 has yet to be determined; initial reports are very low, while SARS/MERS respectively have an 18% and 25% mortality rate in this population.1,5,6

Mother With Baby

  • 1st trimester: In other infections, developing a fever in the first trimester doesn’t contribute to birth defects, though it does increase the likelihood of inattention disorders in childhood.1 Because of the timeline of the pandemic, we don’t have data on COVID-19-related effects from young children born to mothers who had the infection, but experts hypothesize the same may hold true.1 Based on small numbers of COVID-19 cases, it doesn’t appear to increase the risk for miscarriage (spontaneous abortion) above the risk of the general population.1,7
  • 2nd/3rd trimester: Data from small numbers of cases show COVID-19 infection poses fetal risks, such as intrauterine growth restriction (9-10%) and preterm birth (39-43%), though the preterm birth information is somewhat conflicting.1,7,8
  • Early childhood: COVID-19 presents mostly as a mild respiratory illness in most children.1
  • Predicting severity of COVID-19 in pregnancy: Assessing and predicting mortality of COVID-19 in pregnant patients is more difficult than in nonpregnant patients, as the normal course of pregnancy skews measures used to predict the course of disease, such as D-dimer and sequential organ failure assessment (SOFA).1 This can make it a bit more difficult to predict when the severity of a case may increase and require higher levels of interventions.
  • Treatment of COVID-19 in pregnancy: Pregnant women who develop severe disease and require a ventilator need higher levels of oxygen to adequately provide for their growing fetus.1 Remdesivir, the most promising drug for the treatment of COVID-19, appears to be safe for use during pregnancy, as does chloroquine, though it may require higher doses in pregnant patients.1 An HIV antiviral being used, lopinavir-ritonavir, is safe in pregnancy, as demonstrated through public health data.1 Unfortunately, ribivarin, an antiviral drug, and baricitinib, a Janus kinase inhibitor being used for COVID-19, aren’t safe to use during pregnancy.1 Pregnant and breastfeeding women are excluded from current vaccine phase 1 and 2 clinical trials, though some OB/GYNs argue this is “both misguided and not justifiable and may have excluded them from potentially beneficial interventions.”9-11
  • Special considerations for pregnant healthcare workers: N95 masks can reduce oxygen uptake and are recommended against (as is frontline work) for pregnant women working in healthcare with growth-restricted fetuses.1
  • Vertical transmission (mother spreading the virus to baby): In theory, passing the infection from mother to baby while in utero is possible due to ACE2 (the receptor the virus uses to enter cells) expression on the placenta; however, no confirmed cases proving this have been recorded to date.1 A study published in JAMA found IgG and IgM antibodies against SARS-CoV-2 in newborn infants born to COVID-19-positive mothers.12 Since IgM does not cross the placenta, it suggests the infants were possibly exposed to the virus in utero; however, throat swabs and blood samples from the babies were negative for the virus.12 Measuring IgM antibodies has limitations with the possibility of false positives, so more evidence is needed to confirm the infection could be passed this way.13 In cases where a baby tested positive after being delivered by a COVID-19-infected mother, other causes of transmission could not be completely ruled out.1 Additionally, in COVID-19-positive mothers the virus does not seem to appear in amniotic fluid, umbilical cord blood, breast milk, or throat swabs from the infants.1
  • Delivery, breastfeeding, and skin-to-skin contact: Numerous reputable professional obstetrics societies declare vaginal delivery is safe for women with COVID-19, without risk of spreading the infection to the infant.1,8 Women with the infection may need to wear a facemask and avoid skin-to-skin contact with their new babies after delivery; however, all evidence suggests it is safe for the baby to drink breastmilk—which should bring some comfort to both.1

Conclusion
Pregnant women are not more likely to get COVID-19, nor are they more likely to have a severe case based on the findings so far. While COVID-19 infection during pregnancy certainly presents possible risks to them and their babies, the emerging evidence is reassuring. In the absence of other modifying factors that increase risk and course of disease, pregnant women can reasonably expect that contracting COVID-19 while pregnant has the same risks as nonpregnant patients of similar makeup. Treatment options for pregnant women are mostly similar, with some limitations. There is no compelling evidence that pregnant women can spread the infection to their babies, other than normal transmission routes, namely respiratory droplets. Should their babies develop the infection, the course is generally mild in children.

The American College of Obstetricians and Gynecologists (ACOG) along with the Centers for Disease Control (CDC) has created guidelines based on the available research to date; however, there are still several unanswered questions, and additional information is needed to make better informed decisions.  Therefore, those clinicians with pregnant women under their care should routinely monitor any changes and updates to these recommendations.

Citations

  1. Dashraath P et al. Coronavirus disease 2019 (COVID-19) pandemic and pregnancy. Am J Obstet Gynecol. 2020. pii: S0002-9378(20)30343-4.
  2. Khalil A et al. SARS-CoV-2 in pregnancy: symptomatic pregnant women are only the tip of the iceberg. Am J Obstet Gynecol. pii: S0002-9378(20)30529-9.
  3. Coronavirus Resource Center. Johns Hopkins University and Medicine. https://coronavirus.jhu.edu/map.html. Accessed May 14, 2020.
  4. Blitz MJ et al. Intensive care unit admissions for pregnant and non-pregnant women with COVID-19. Am J Obstet Gynecol. 2020. pii: S0002-9378(20)30528-7.5.
  5. Karami P et al. Mortality of a pregnant patient diagnosed with COVID-19: A case report with clinical, radiological, and histopathological findings. Travel Med Infect Dis. 2020;101665.
  6. Hantoushzadeh S et al. Maternal death due to COVID-19 disease. Am J Obstet Gynecol. 2020;S0002-9378(20)30516-0.
  7. Yan J et al. Coronavirus disease 2019 (COVID-19) in pregnant women: A report based on 116 cases. Am J Obstet Gynecol. 2020;S0002-9378(20)30462-2.
  8. Della Gatta AN et al. COVID19 during pregnancy: a systematic review of reported cases. Am J Obstet Gynecol. 2020;S0002-9378(20)30438-5.
  9. Safety and immunogenicity study of 2019-nCoV vaccine (Mrna-1273) for prophylaxis of SARS-CoV-2 iInfection (COVID-19). ClinicalTrials.gov. https://clinicaltrials.gov/ct2/show/NCT04283461?term=mrna-1273&draw=2&rank=1. Accessed May 13, 2020.
  10. Safety, tolerability and immunogenicity of INO-4800 for COVID-19 in healthy volunteers. ClinicalTrials.gov. https://clinicaltrials.gov/ct2/show/NCT04336410?term=ino-4800&draw=2&rank=1. Accessed May 13, 2020.
  11. Costantine MM et al. Protection by exclusion: Another missed opportunity to include pregnant women in research during the coronavirus disease 2019 (COVID-19) pandemic. Obstet Gynecol. 2020. [Epub ahead of print].
  12. Zeng H et al. Antibodies in infants born to mothers with COVID-19 pneumonia. JAMA. 2020;323(18):1848‐1849.
  13. Kimberlin DW et al. Can SARS-CoV-2 infection be acquired in utero?: Moredefinitive evidence is needed. JAMA. 2020. [Epub ahead of print].