Hot off the press the world talking about COIVD-19, the pneumonia-causing virus that was first reported as an outbreak in WuHan China at the end of 2019.
Viruses are thought of as ‘molecular pirates or wizards’, as they are cunning and sneaky in the way they replicate and hijack the host’s cells.
COVID-19 is a disease that has mutated and evolved over time to be able to infect humans. Viruses have no properties of normal cells, such as a nucleus, or ribosomes, meaning that they are intracellular parasites that depend completely on their host.
What we need to remember at this point in time is that we have over come HIV, Hepatitis, Zika and SARS (2002), when it comes to pregnancy, IVF and the human race.
There is one plus for pregnant women with COVID-19. Unlike Zika, it has not yet been proven that the virus crosses the membrane barrier to the baby causing any issues to a pregnancy. So far babies born have not been infected.
The Science
The protein structure from SARS (2002) and SARS-CoV-19 are both a three prong structure for attachment to the hosts cells derived from an animal virus that show 77.5% identical in the amino acid sequence. But to show how sneaky these viruses are, the COVID-19 virus has changed its protein receptor at its three-prong attachment so that it is only 46% identical to SARS-CoV-2.
What does this mean? This means that people who were previously infected by SARS in 2002, their antibodies will not attack the new virus, leaving them vulnerable to infection.
How does COVID-19 impact IVF?
The good news is, that Covid-19 is unlikely to replicate during IVF procedures, scientist use a techniques use in the lab for HIV patients. This involves a special process of washing out the viral load from the sperm, use single use items per patient, stringent cleaning procedures, and correct personal protective equipment for all staff involved.
A study by Pan et al, 2020 showed evidence that Covid-19 is not present in semen from male’s patients that had been infected.
An interesting note, Covid-19 lasts for up to 3 hours in the air from a cough or sneeze, up to 4 hours on copper, and 24 hours on cardboard and up to 2 to 3 days on plastic and stainless steel. Where as hepatitis is stable in dried blood for up to 4 months!
It has been discussed that using the normal dilution process for washing and cleaning embryos would allow for very low risk of the virus being attached to the embryo in the lab during procedures and during the freezing thawing process. It has been discussed that all potential patients at this stage may need to use the ICSI procedure to make sure they are minimizing risk. The precautions would need to be taken when coming in close distance to patients for embryo transfer, and making sure it is not passed from aerosols or vaginal fluid at this time.
The bottom line is that all human tissue should be considered as potentially infectious, meaning that a strong quality control policy is essential for all IVF laboratories.
What does it mean for those who are already pregnant?
The good news for pregnant women is that it is thought so far there is no reason the uterus would use the angiotensin-converting enzyme 2 (ACE2) that has been found to be the functional receptor for covid-19. This enzyme is found in oral and nasal mucosa, lung, stomach, small intestine, colon, lymph nodes, thymus, bone marrow, spleen, liver, kidney and brain. Being most abundant in the lung leading to the route of infection, and the less likelihood of it passing through the placental barrier.
In a study by Dashraath, P et al, 2020 reported 55 cases of pregnant women with Covid-19 with 46 babies that were born and there is no evidence so far of vertical transmission. This means that at this stage they have not seen mum pass Covid-19 to their baby.
Although babies at this stage seem to be safe from contracting Covid-19 in utero, this is not the same for you. Mum becomes more susceptible to infections such as viruses during pregnancy.
During pregnancy the immune system has a bias towards your unborn baby over mum. Therefore mum is more at risk of infections such as Covid-19 leading to death due to the compromised immune system.
A review by Karimi-Zarchi, M et al, 2020 found the symptoms of pregnant women and non-pregnant women were the same for infections with Covid-19. They found that after delivery their babies tested negative for Covid-19 but there was an increase in maternal death after birth due to the compromised immune system.
In the same review it was reported that out of 5 women looked at in early pregnancy (1st trimester), 2 of the women in the study had a normal placenta whereby the other 3 women had a change in the placenta, thought to be associated with abnormal blood flow to the placenta.
It was also noted by Chen, S et al 2020, pregnant women infected with Covid-19 did not show fever until after delivery.
In conclusion to the studies so far we know there are more studies needed, higher sample sizes than 5 or 55 pregnant women and women of all stages of pregnancy.
The take home advice is, for infected women to be more careful and higher care needed leading up to birth. Take all precautions when breast feeding your newborn to not infect your baby via aerosols from mum
References:
Chen, S., Liao, E., Shao, Y., 2020. Clinical analysis of pregnant women with 2019 novel coronavirus pneumonia ‘Medical Virology’ 1-19
Dashraath, P., Jing Lin Jeslyn, W., Mei Xian Karen, L., Li Min, L., Biswas, A., Ariandas Choolani, M., Matter, C., Lin S, L., 2020. Coronavirus Disease 2019 (COVID-19) Pandemic and Pregnancy ‘American Journal of Obstetrics and Gynecology’ 1-47
Hamming, I., Timens, W., Bulthuis, M, L., Lely, A, T., Navis, G., van Goor, H., 2004. Tissue distribution of ACE2 protein, the functional receptor for SARS coronavirus. A first step in understanding SARS pathogenesis ‘Journal of Pathology’ 203(2): 631-7
Karimi-Zacrchi, M., Neamatzadeh, H., Dastgheib, S, A., Abbasi, H., Mirjalili, R., Behforouz, A., Ferdosian, F., Bahrami, R., 2020. Vertical Transmission of Coronavirus Disease 10 (COVID-19) from infected Pregnant Mothers to Neonates: A Review ‘Fetal and Pediatric Pathology’ 1551-3823 (online).
Pan, F., Xiao, X., Guo, J., Song, Y., Li, H., Patel, D., Spivak, J., Alukal, J., Zhang, X., Xiong, C., Li, P., Hotaling, J, 2020. No evidence of SARS-CoV-2 in seman of males recovering from COVID-19. Fertility and Sterility’ 1-11
Vankadari, N and Wilce, J, A., 2020. Emerging WhuHan (COVID-19) coronavirus: glycan shield and structure prediction of spike glycoprotein and its interaction with human CD26 ‘Emerging Microbes and Infections’ 9(1): 601-604