In a new study published in BMC Pregnancy and childbirth, researchers discuss the basic and clinical science of the potential interrelationships between diabetes mellitus and coronavirus disease 2019 (COVID-19) during pregnancy.
Examination: SARS-CoV-2 in diabetic pregnancies: a systematic review of the extent. Image Credit: Halfpoint / Shutterstock.com
About the study
Both COVID-19 and diabetes mellitus are pandemic. Increased severity of COVID-19, which is caused by infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been reported in patients with diabetes mellitus. However, the clinical consequences of COVID-19 in diabetic pregnancies are unknown.
To better understand this, the researchers in the current study conducted a systematic scope analysis in MEDLINE (PubMed), EMBASE, CINAHL, Cochrane Library, and the Web of Science Core Collection in September 2020.
Following PRISMA for systematic reviews and the Joanna Briggs Institute for Systematic Scoping Reviews guidelines, the researchers conducted literature searches on COVID-19 and Diabetes Mellitus (I), COVID-19 and pregnancy (II), and COVID-19 and diabetic pregnancies (III). The researchers were specifically interested in pathophysiological mechanisms, clinical outcomes and functions, screening and management.
The prognosis for pregnant women with diabetes mellitus and COVID-19 may be associated with potential underlying mechanisms, such as a simplified viral uptake of angiotensin-converting enzyme 2 (ACE2), which is the major receptor for SARS-CoV-2, a higher basal value of proinflammatory cytokines, as it is hypoxic as well as platelet activation, embolism and preeclampsia. COVID-19 may predispose infected individuals to the onset of diabetes mellitus.
SARS-CoV-2 and diabetes
Although diabetes mellitus and cardiovascular disease were the most common comorbidities observed in SAR-CoV-2 patients, several studies have reported that the incidence of diabetes mellitus is twice as high in severe cases of COVID-19. . In addition, diabetic patients with COVID-19 have a greater risk of being admitted to the intensive care unit and longer stays in the hospital.
The study observed that in COVID-19 patients with diabetes mellitus there was a higher risk of severe pneumonia, release of tissue damage enzymes, higher serum levels of inflammation-related biomarkers, altered and weaker immune response and an increased risk of prothrombotic events.
Overall, there are clear indications that the prognosis for patients diagnosed with COVID-19 and DM may be associated with a simplified viral uptake of receptor angiotensin-converting enzyme 2 (ACE2), with a higher basal value of proinflammatory cytokines, which facilitates a cytokine storm, with being hypoxemic and with elevated levels of IL-6 and AMPK / mTOR signaling pathways. ”
SARS-CoV-2 and pregnancy
Current estimates indicate that about 10% of pregnant women are diagnosed with COVID-19. Of these, pre-existing diabetes was associated with severe COVID-19 during pregnancy rather than gestational diabetes.
While there are currently limited data on maternal, fetal and neonatal outcomes for pregnant women with SARS-CoV-2 infection, there is a greater risk of pregnancy complications, including premature birth and preeclampsia. High body mass index (BMI) and high maternal age are other risk factors for severe COVID-19 in pregnant women.
Problems such as fever, cough, fetal distress, cesarean birth and lymphopenia, to name just a few, were found in a small percentage of women. In particular, the studies the authors reviewed found no cases of severe pneumonia and maternal death. All infants born to these mothers also had good Apgar scores. In addition, the presence of SARS-CoV-2 was not detected in amniotic fluid, breast milk, umbilical cord blood and neonatal sore throats.
Potential mechanisms involved
ACE-2 is expressed in several important metabolic organs and tissues, some of which include beta cells in the pancreas, adipose tissue, small intestine and kidneys. Therefore, infection with SARS-CoV-2 may lead to changes in glucose metabolism and thus complicate the pathophysiology of pre-existing diabetes mellitus or lead to other mechanisms such as insulin deficiency and increased risk of diabetic ketoacidosis.
Metabolic imbalances that occur with viral diseases are well known. SARS-CoV-2 damages islands and causes newly started diabetes mellitus. Although there is no current evidence for the role of new diabetes mellitus in pregnant women, it is conceivable that COVID-19 may also trigger gestational diabetes.
Hypoxia triggered by pneumonia and dysfunction caused by SARS-CoV-2 infection is a major clinical outcome in COVID-19 patients. COVID-19 patients with DM had an increased risk of hypoxemia, which was independently associated with hospital mortality.
Hypoxic damage to the placenta and the development of a pre-eclampsic condition are associated with the hyperinflammatory condition of COVID-19. Current evidence indicates that preeclampsia may be common in pregnant COVID-19 patients.
Interaction between SARS-CoV-2, diabetes mellitus and pregnancy.
Severe maternal inflammatory status caused by SARS-CoV-2 may result in inflammation of the placenta. Transmission through the placenta is also observed.
“Therefore, SARS-CoV-2 may cause maternal viremia, placental infection, placental inflammation and neonatal viremia.”
These changes can also cause cross-generational programming, which includes fetal, perinatal, and in utero programming. Together, these effects can lead to long-term consequences for the offspring.
When looking at the screening and management of COVID-19 during pregnancy, complications due to restrictions and social distance measures limit these pregnant women’s health care, tests, medications, and diet. These measures may therefore lead to the detection of only high-risk women or the inability to identify gestational diabetes early. Digital medicine and care can therefore help as an innovative tool involving telemetric interventions or the use of smartphone apps.
Published data on COVID-19 and pregnant women with diabetes mellitus are currently insufficient and knowledge in this area is growing. However, the risk of severe COVID-19 for a pregnant diabetic woman is high.
Given the challenges of clinical management as well as the complex and transgenerational interplay between COVID-19 and diabetic pregnancies, the researchers in this study emphasized the need for evidence-based recommendations.
“We expect our review to be a starting point for understanding and analyzing mechanisms and epidemiology to most effectively treat women with SARS-COV-2 and diabetes during pregnancy.”