Fertility Preservation
What is Fertility Preservation?
Fertility preservation is an emerging field that provides the opportunity to maintain the reproductive health to all those patients who either have to receive medical treatment most commonly being cancer related treatments(Oncofertility) or want to preserve their gametes to postpone childbearing(social fertility preservation)
It can be offered to both males and females.
The treatment of cancer in the form of chemotherapy, radiotherapy and surgery can affect fertility and future childbearing. There are ways whereby fertility can be preserved prior to starting any of the above treatments.
Fertility can be preserved by following methods-
- Embryo cryopreservation
- Oocyte cryopreservation
- Sperm cryopreservation
- Ovarian tissue cryopreservation
- Fertility sparing surgeries
Oocyte cryopreservation
Oocyte (egg) freezing or cryopreservation is a procedure of freezing good quality and mature oocytes for further use. They can then be fertilised with sperm at a later stage whenever a woman plans to start a family.
What does oocyte cryopreservation involve?
It involves stimulation of ovarian follicles with injections known as Gonadotrophins which are same as in IVF procedure.
What is Ovarian Stimulation?
During IVF treatment, hormones in the form of injections are given to stimulate ovaries with more than one egg with purpose of collecting all eggs and selection. This process involves daily injections for 9-11 days during which follicular monitoring happens to assess the growth of eggs. Once 3 or more eggs reach size of 18mm, they are collected outside by a process of egg collection.
What is egg collection (oocyte retrieval)?
This is a minor surgical procedure which involves collection of eggs. This process is ultrasound guided. A small needle is inserted through the vagina into the grown up follicles. Follicles are aspirated and handed over to embryology laboratory to confirm for presence or absence of oocytes in a particular follicle and also confirm total number of oocytes retrieved.
The procedure of egg collection is done under mild anaesthesia (LMA- Laryngeal mask airway). Sometimes, it is done with pain killers and sedation. Total procedure timing including anaesthesia delivery is half an hour. Women do not feel anything during the procedure (they are relaxed and comfortable).
Recovery is quick and generally a woman is fit for discharge four hours after the procedure.
The eggs are then assessed for their maturity in embryology labarotary and prepared for Vitrification.
What is Vitrification?
It is one of the methods of freezing of the Oocytes and Embryos.
The development of and improvements in cryopreservation technology over the last decade have helped to increase overall clinical pregnancy rates from a single oocyte retrieved.. There are two different types of cryopreservation: vitrification and slow freezing.
The process of slow freezing the egg is long and involves step-wise programmed decrease in temperature. The procedure is lengthy and hence, there are increased chances of ice crystal formation within the cell being frozen which in turn can have extremely deleterious effects.
Vitrification is a rapid method of freezing over few minutes. It solidifies the cell into a glass-like state, thus, avoiding the formation of both intra and extracellular ice crystals and hence, risk of damage to cells. This is usually accomplished through the use of relatively high concentrations of cryoprotectant agents (CPA) and/or very high cooling rates (15,000–30,000°C/min). This technique is far more time-efficient, requiring only several minutes (12-15 mins.), compared with 1-2 hours with controlled-rate slow freezing.
Embryo Cryopreservation
Embryo cryopreservation is a procedure of preserving fertised egg(Embryo).
The development of and improvements in cryopreservation technology over the last decade have helped to increase overall clinical pregnancy rates from a single oocyte retrieved.. There are two different types of cryopreservation: vitrification and slow freezing.
The process of slow freezing the egg is long and involves step-wise programmed decrease in temperature. The procedure is lengthy and hence, there are increased chances of ice crystal formation within the cell being frozen which in turn can have extremely deleterious effects.
Vitrification is a rapid method of freezing over few minutes. It solidifies the cell into a glass-like state, thus, avoiding the formation of both intra and extracellular ice crystals and hence, risk of damage to cells. This is usually accomplished through the use of relatively high concentrations of cryoprotectant agents (CPA) and/or very high cooling rates (15,000–30,000°C/min). This technique is far more time-efficient, requiring only several minutes (12-15 mins.), compared with 1-2 hours with controlled-rate slow freezing.
Sperm Cryopreservation
It involves freezing of ejaculated sperm. The sample is generally frozen in multiple vials. The number of vials depend on quality of semen sample. The quality of semen sample is assessed by number, movement and shape of sperm.
In case semen sample shows inadequate number of sperms, patient is asked to come again for repeat samples. Some cancers affect the sperm count and hence, one sample may not be enough for freezing Generally, 5 to 6 vials of semen sample are recommended to be frozen before they start their chemotherapy treatment.
So, sometimes the patient is asked to come multiple times to preserve adequate amount of sperm samples.This is only recommended if there is time available before the start of cancer treatment. If ejaculatory sample is not possible, then electro ejaculation or testicular extraction of semen sample is recommended for freezing . There are some cancers where the risk is more such as high-grade Hodgkin’s lymphoma, testicular tumours.
Please speak to your IVF doctor if you need more information on freezing or preserving your fertility before your cancer treatment.
Ovarian Tissue Cryopreservation
This method of preserving fertility is a relatively new procedure. It is offered as being experimental . This procedure though holds a promising future and will hopefully be classified as standard procedure in the near future.
Around 100 children have been born so far by this procedure. This procedure involves removing a portion or whole of ovary and dissecting out the outermost part of ovary known as ovarian cortex.
Ovarian cortex is sliced into small pieces and frozen by either slow freezing method or by rapid freezing method known as vitrification. Once a woman has completed her cancer treatment and her oncologist feels safe for her to plan a pregnancy then this tissue can be replaced back into woman's pelvic area with the aim of achieving pregnancy either spontaneously or through IVF.
Fertility sparing surgeries
This kind of fertility preservation methods is mainly considered in those cancers where a male or a female is already undergoing a surgical procedure for the cancer treatment. This is mainly considered in those cancers which involve reproductive organs like uterus, ovaries, cervix, vagina, testicular area.
Whether these surgeries are applicable or not will depend on stage and grade of cancer. Oncologist in discussion with reproductive medicine specialist can make this decision better with you.
Dr. Puneet Arora is one of the best fertility treatment doctor in Gurugram, India with a successful career of more than 20 years. Dr. Puneet is an expert in this field and is one of the best IVF specialist and Gynecologist in Delhi/NCR. – She may explain more about Blastocyst in case you wish to discuss further.
