Abstract
Study question
Is it possible to find viral Sars-Cov–2 RNA in FF of women undergoing treatment during Covid–19 pandemic that may compromise gamete and embryo safety?
Summary answer
No viral RNA was detected in tested FF of women undergoing IVF in compliance with recommendations. This was reassuring and supported good medical practice.
What is known already
Risks due to SARS-CoV–2 during IVF remain difficult to assess despite the screening recommended by French health authorities based on a symptom questionnaire of the couple (systematic testing by RT-PCR for the virus before egg retrieval (ER) is not mandatory). In this context, this is a real challenge for IVF laboratory to guarantee procedure, patients, gametes and embryos safety. Most studies have reported the absence of virus in sperm. No data are available for FF and only one study looked for the presence of the virus in oocytes of Covid-affected patients (Barragan M et al, 2020).
Study design, size, duration
Between June 17 and September 24, 2020, FF of consenting women were prospectively collected and symptom questionnaire recorded. During this period, women undergoing IVF in our center did not benefit from systematic PCR testing for the virus within 72 hours prior to ER through our health authorities’ recommendations. All collected FF were retrospectively tested to research viral RNA by RT-PCR and patients were recalled to answer an epidemiological follow-up questionnaire.
Participants/materials, setting, methods
For all couples, symptom questionnaires were prospectively recorded and verified at each step of IVF procedure. For all consenting women, a sample of 1 ml of FF was collected the day of ER and stored at –80 °C. After thawing, a Sars-Cov2 multiplex RT-PCR using CFX96 (Biorad*) was performed, after RNA extraction using Nimbus (Seegene*). A comprehensive epidemiological evaluation was made afterwards by phone interview and data were recorded and analyzed.
Main results and the role of chance
A total of 183 women was included out of the 214 treated during this period (85.5%). Retrospective epidemiological evaluation showed that 8 patients contracted Covid more than 2 months before the ER, 6 more than 2 months after and only one patient 1 month after ER (diagnosis based on pathognomonic signs as agueusia and anosmia or/and positive PCR ). We observed a prevalence of symptomatic Covid forms in our IVF population of 8.2% during a 6-month period surrounding their IVF cycle. Moreover, until the introduction of systematic testing by RT-PCR for the virus before ER since the end of September 2020, 3 patients have been cancelled out of the 403 planned for positive PCR despite a negative questionnaire, which represents a prevalence of asymptomatic forms on the day of the ER at 0.7%. All the 183 FF tested did not reveal any viral RNA detection, which was reassuring concerning our medical practice and patient compliance and transparency. The absence of detected viral RNA may be due to several reasons: 1) women were not infected the day of ER 2) women had an asymptomatic form of the disease with low viral load 3) FF is not a virus reservoir.
Limitations, reasons for caution
Not all patients were included (85.5%). Post-diagnosis stays uncertain because PCR tests at the beginning of the epidemic were not mandatory and hardly available.
Wider implications of the findings: The absence of viral RNA in FF of women only screened through a symptom questionnaire is reassuring concerning the safety of IVF during Covid pandemic.
Trial registration number
Not applicable
Detection of Schmallenberg Virus RNA in Bull Semen in Poland