The expectant mothers and fathers who chose IVF technology began to anxiously wait for the results of embryo culture after the eggs were retrieved. When you ask the doctor about the egg fertilization, you will often hear: Normally fertilized xx embryos, abnormally fertilized xx embryos ". What does it mean?
( sperm and egg during formation of the zygote )
current IVF fertilization There are two main ways:
Conventional in vitro fertilization (IVF): is to take sperm or eggs out of the body, process or culture them into embryos, and then implant them into the mother.
Intracytoplasmic Sperm Microinjection Fertilization (ICSI):
Intracytoplasmic sperm injection fertilization (ICSI): will be injected into 1span _strong11 sperm cells.The egg is fertilized, cultured in vitro to an early embryo, and then returned to the mother's uterus for development and implantation.
01, So what does PN mean?
"PN" is the English abbreviation of "pronucleus". Usually the embryologist will observe the fertilization of the egg on the morning of the egg retrieval day. At this time, one of the fertilized eggs will appear under the microscope. Multiple circles, this is the "pronucleus". The appearance of pronucleus represents the completion of sperm and egg fertilization.
As time goes by, the pronucleus becomes more and more obvious, with obvious nuclear membrane and nucleolus. The emergence of the pronucleus represents a crucial step for the "parents-to-be and mothers-to-be" to succeed in pregnancy.
02, what is normal fertilization, what is abnormal fertilized it?
two prokaryotic (2PN)
Normally fertilized eggs can see two pronuclei (called 2PN),The two pronuclei are generally uniform in size and located in the center of the cytoplasm of the fertilized egg, indicating that the egg is fertilized normally.
single pronucleus (1PN) _spanspan_span_span1 _span4 The nucleus of the cell forms a pronucleus, and a pronucleus is called "1PN".
Some of these fertilized eggs can develop into good quality embryos, but the occurrence of chromosomal abnormality (haploid and chimera) cannot be ruled out, so if "Moms and Dads" When only 1PN embryos can be used, your attending doctor will talk to you about the risks and sign an informed consent form before they can be transplanted or frozen.
Multiple pronuclei: the most common is 3 pronuclei (3PN) _span1 _span1 _span1 _strong , All have formed the pronucleus,At this time, "3PN" or even "4PN" will be observed. Multi-prokaryotic embryos are not acceptable. Because multi-prokaryotic embryos have an extra set of genetic material , early embryonic death, miscarriage, and fetal genetic diseases often occur!
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_p15brpbr p31 span 8 Zero pronucleus 0PN)
If the egg is not fertilized and no sperm enters, it means that the combination of sperm and egg fails, and the pronucleus will not be formed. We usually call it "0PN". There are many reasons for unfertilization, such as egg quality: egg maturity, abnormal zona pellucida, etc.; sperm: the number, vitality and morphology of sperm will have a certain impact on fertilization.
Abnormally fertilized "0PN", "1PN", "3PN" embryos sometimes divide normally, and even form strong span blastocysts. However, the implantation rate after transplantation is much lower than that of normal "2PN" embryos. Even if they can be implanted, these embryos often cannot continue to develop to the later stage of pregnancy, leading to embryo abortion and abortion. Therefore, embryologists should observe and record the formation of the pronucleus of the fertilized egg, and try to choose normal developing embryos to avoid causing losses to the patient.
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