Dr. Shivani Sachdev Gour at SCI Healthcare explain Natural Hatching

Natural hatching

Once the blastocyst differentiates into trophoblast and embryoblast, the cells swell and multiply. By now the embryo is 3 to 5 days old and it has reached the uterine cavity.

Ovum is covered by a gel like thick membrane called “zona pellucida”. In natural state, zona is essential to prevent multiple sperms from entering the ovum. It is important that the blastocyst should not implant in fallopian tube, otherwise ectopic pregnancy will occur. The presence of zona will allow the embryo to reach uterus safely before hatching occurs. But if the zona becomes thickened, then natural hatching may fail. Some studies have found out that 75% normal embryos do not hatch on their own. Enzymes in the fallopian tube soften the zona. If it softens very fast, of the tube is too long or kinked or in cases where some infection cause excess secretion of enzymes – the zona dissolves early and an ectopic pregnancy (pregnancy in the tube) can occur. In older age patients, in IVF cycles where there are no tubal enzymes to help, or in cases where the cryopreserved (frozen) ovum or embryo are used, the zona can be hard and hatching may fail.

Methods of Assisted Hatching:--

Assisted hatching means using methods to artificially dissolve the zona pellucida so that hatching can occur. This can be done using chemicals or laser.

Chemical hatching:-- This uses chemicals to dissolve the zona. This is difficult as very small quantity of chemicals should be used precisely and with speed and the excess acid should be washed off fast to prevent injury to the blastocyst. Overdose may injure the blastomeres and may create birth defects.

Laser hatching:-- in this a microlaser gun is used and with precision a hole is drilled on one side involving the zona only. With practice, and good programming, adequate care can be taken so that the blastomeres are not affected. A vibration free table improves the accuracy and avoids any sudden movement of the embryo during the process. This is a safer alternative to chemical hatching.

Older patients more than 37 years, when cryopreserved (frozen) embryo is used, previous failures, very low AMH values, patients needing very high dose of injections, low fertilization rate ( only few ova are fertilized ), very few embryos (1 to 3)

Oopause:-- This is a stage where the fertility is poor, oocyte quality is poor but the hormone levels of FSH, E2 and LH are still normal. The response of these patients to IVF protocols is poor. They may need high levels of Inj FSH, may produce three or less oocytes, have many empty follicles, may fail to fertilize or hatch. Also the abortion rates are very high. This stage is pre menopause. Patients often benefit from oocyte donation.

Website:-- surrogacycentreindia.com