In vitro fertilization egg and sperm retrieval: Parents’ cleanliness obsession can save the baby’s life!

Author: Chen Weiwei, Chief Technician, Sichuan Jinxin Xinan Women and Children's Hospital

Reviewer: Meng Xiangqian, Associate Researcher, Sichuan Jinxin Xinan Women and Children's Hospital

For parents who have undergone egg and sperm retrieval surgery, the most common questions heard on the day of the operation are not only the identity information verification of the staff, but also a series of detailed inquiries from the embryologist. These questions include: "Is all the semen collected in the semen collection cup? Is there any semen missed?" "Did you wash your hands before semen collection?" "Have you touched the inside of the semen collection cup?" "Did you defecate before semen collection?" "Did you take a shower after defecation?", etc. Behind these questions is a common goal: to ensure that the semen is not contaminated by pathogens. Once the gametes (sperm or eggs) or embryos are contaminated, it may result in no embryos available, or even all embryos apoptosis. Therefore, if there is a risk of contamination, the embryologist should be informed truthfully so that the embryologist can take timely treatment measures according to the specific situation.

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Although all technical operations in the laboratory are performed under sterile conditions, contamination cannot be completely eliminated. Understanding which factors may bring contamination risks and taking corresponding preventive measures is the key to ensuring the success rate of IVF.

1. What are the sources of pollution risks?

1. Improper sperm collection methods that are contaminated by sperm. During sperm collection, if the operation is improper, pathogens may be introduced. According to literature reports, during in vitro fertilization-embryo transfer, sperm-derived contamination accounts for 63% to 100% of all contamination.

2. Egg-derived contamination: Inflammatory pathogens present in the vagina may contaminate the egg retrieval process.

2. How to avoid pollution risks?

1. Prevention of sperm source contamination

(1) Take care of the inside of the sperm collection cup: Treat the inside of the sperm collection cup as if it contains a treasure that cannot be exposed to any microorganisms. Do not touch the skin because the skin carries a large number of bacteria, the most common of which is epidermal Staphylococcus. If the inside of the sperm collection cup is touched, the embryologist should be informed immediately, and a clean sperm collection cup should be replaced to collect semen again.

(2) Wash your hands thoroughly: Wash your hands thoroughly before collecting semen, and wait until your hands are completely dry before collecting semen to prevent moisture from your hands from entering the semen collection cup during the collection process. Be careful not to use disinfectants containing alcohol to avoid affecting the quality of semen.

(3) Adequate cleaning: If you have bowel movements, you should do a thorough cleaning. Because there are more intestinal flora, microorganisms such as Enterobacteriaceae and Coccus will compete with gametes and embryos for nutrients. The endotoxins and exotoxins they secrete will affect the development of the embryo. In severe cases, it may cause the gametes and embryos to completely degenerate.

(4) Pay attention to hand hygiene: During the sperm collection process, you must "control" your hands and do not touch items in the sperm collection room, such as the sofa, because you do not know what the previous user did to the room. If you accidentally touch it, wash your hands carefully and keep them clean.

(5) Avoid using condoms to collect semen: because condoms may bring skin flakes into the semen, affecting the quality of semen.

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2. Prevention of egg-derived contamination During in vitro fertilization-embryo transfer (IVF-ET), although egg-derived contamination is relatively rare, it still needs to be taken seriously.

(1) Prevent vaginal microbial contamination: Egg-derived contamination mainly comes from vaginal microorganisms. When women have bacterial vaginitis or candidal vaginitis, the risk of contamination increases significantly. Common vaginal pathogens include bacteria (such as Escherichia coli, Streptococcus) and fungi (such as Candida). If there is an infection, it should be treated promptly.

(2) Personal cleanliness before egg retrieval: Take a shower before going to bed the night before egg retrieval and clean your vulva by yourself to ensure that the vulva is clean. Be sure to use mild cleansers and avoid using soap, as soap may change the acid-base balance of the vagina and increase the risk of infection.

(3) Medical measures on the day of egg retrieval: On the day of egg retrieval, the doctor will perform multiple flushing to reduce the risk of contamination of the oocyte collection needle. The egg retrieval process should be carried out under sterile conditions, and all instruments and materials used should be strictly sterilized.

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I hope that every mother who undergoes egg and sperm retrieval surgery can understand the importance of the above issues, actively cooperate with the work of medical staff, and create the best conditions for the birth of the baby.