With the opening up of new crown epidemic control, after three years of epidemic prevention, we finally realized the freedom to travel at this moment, but before we had time to see the world, we suddenly found that we seemed to have entered the "sheep pen", and everyone around us became "Xiaoyang people".
This has caused panic and mental burden for many people preparing for pregnancy and pregnant women, especially for couples who are undergoing in vitro fertilization.
Does novel coronavirus infection affect the outcome of assisted reproduction (ART)?
Research shows that the new coronavirus mainly enters human cells through the ACE-2 receptor on the surface of human cells, with respiratory epithelium as the main target. The main symptoms are fever, fatigue, dry cough, etc.
So, will the new coronavirus attack the female reproductive system?
Research has found that severe infection with the new coronavirus may affect the menstrual cycle, mainly manifested by heavy menstrual flow and prolonged menstrual periods. No significant effects were found on ovarian reserve, function and follicular fluid parameters. However, some studies have shown that viral RNA can be detected in the follicular fluid of severely ill patients. The expression of ACE2 in the ovarian cortex and medulla is extremely low, indicating that these tissues are less likely to be infected; and there are relatively high positive cell rates in different development stages of follicles and , and the ACE2 positive cell rate in egg cells before and after during the ovulation period of is 100%. It is suggested that there is a risk of new coronavirus infection during follicle development, especially before and after ovulation, and more attention is needed.
However, will these findings necessarily affect pregnancy outcomes on ART? There is no conclusion yet, but in principle it is not recommended to carry out assisted reproductive treatment for patients with symptomatic infection of the new coronavirus. The
study also showed that there is no co-expression of viral receptor ACE2 and transmembrane serine protease 2 (TMPRSS2) related to the onset of infection in the myometrium, uterus or fallopian tube, indicating that these organs have no or only very low susceptibility to new coronavirus infection. Not only that, there is also literature showing that the inactivated new crown vaccine has no impact on the pregnancy outcomes and neonatal outcomes of infertile women who have frozen embryos in the early stage and undergo frozen-thaw embryo transfer (frozen-thaw embryo transfer). Therefore, COVID-19 seems to have little impact on the pregnancy outcomes of frozen-thaw embryo transfer cycles.
If the frozen-thawed embryo is "positive" before the embryo is transferred into the cycle, can the cycle be started first?
We know that the course of COVID-19 infection is about 1 week, and the time interval from entering the frozen-thaw embryo transfer cycle on the 2nd to 5th day of menstruation to the embryo transfer is about 2-3 weeks. Therefore, for patients who want to enter the frozen-thawed embryo transfer cycle as soon as possible for various reasons, if they have just been infected with the new coronavirus when they menstruate, or if the infection is in progress, or if the symptoms have improved and will be cured immediately, etc., no matter they are at any stage of the infection, they can choose to enter the frozen-thawed embryo transfer cycle and prepare the endometrium first. Due to the time interval, most patients with COVID-19 infection can recover before embryo transplantation. nucleic acid test turns negative before transplantation, and current research has not found that COVID-19 infects the myometrium and other uterine tissues. Therefore, for COVID-19-positive patients who urgently need to enter a frozen-thawed embryo transfer cycle, if you are currently in early menstruation, you can consider entering a frozen-thawed embryo transfer cycle.
If you enter a frozen-thawed embryo transfer cycle, we will choose an endometrial preparation plan for frozen-thawed embryo transfer that minimizes the number of visits. For patients with irregular menstrual cycles or short menstrual cycles (short proliferative period, the nucleic acid may not turn negative during ovulation), you can choose a hormone replacement cycle (HRT); you only need to take oral estrogen drugs as directed by your doctor and review them regularly. If you have a regular menstrual cycle (28-37 days), you can choose natural cycle (NC); you only need to test the ovulation test paper at home, and if you find positive , you can come to the hospital for treatment.
After the frozen-thawed embryo is transferred into the cycle, can it continue if it becomes "positive"?
If you develop symptoms of COVID-19 infection after entering the frozen-thaw embryo transfer cycle and find that the nucleic acid test is positive, you need to decide whether to continue based on the time and stage of treatment.
If the endometrium is prepared for a natural cycle or a minimal stimulation program, and COVID-19 infection occurs in the early and middle stages of the follicles, it is considered that it is still 10 days or more before the embryo transfer. The follicles and endometrium can be continued to be monitored. If the embryos have been cured before the embryo transfer and the nucleic acid turns negative, the embryo transfer can be considered. If infection occurs in the late follicle or after ovulation, it is recommended to cancel the cycle considering that the time until the embryo transfer is short.
If you choose a hormone replacement cycle (HRT) or a down-regulated HRT regimen, and infection occurs before progesterone conversion, you need to inform the doctor in time. We will extend the estrogen administration time as appropriate, and try to perform progesterone conversion after the new coronavirus is cured and the nucleic acid turns negative, and then perform embryo transplantation. If COVID-19 infection occurs after progesterone conversion, consider that the time until embryo transfer is short and the cycle needs to be cancelled.
How long does it take for a frozen-thawed embryo transfer to assist in pregnancy?
If the previous cycle was canceled due to COVID-19 infection, how long will it take before I can enter the frozen-thaw embryo transfer cycle again? As mentioned before, the infection and impact of the new coronavirus on the uterus, myometrium or even endometrial tissue have not yet been found. Therefore, patients who have cryopreserved embryos can enter the frozen-thawed embryo transfer cycle again after their menstrual period has recovered from the new coronavirus infection and the nucleic acid has turned negative.
Finally, please adjust your mentality, do a good job in daily life management, actively face the current new situation, take personal protection when going out, wear a good mask, enhance resistance, wash your hands frequently and avoid gatherings, a good mood will make it easier to get pregnant. I hope you can give birth to a healthy baby as soon as possible!
