Busy pursuing educational and career goals, most women these days delay marriage and pregnancy.
This, when it's common knowledge that a woman's fertility levels start dropping between her late 30s and early 40s. However, with rapidly progressing medical technology — the latest, which allows one to freeze eggs for future use — women now have more chances of conceiving even after they cross 35.
Egg-freezing is the latest development in the field of Assisted Reproduction Technology (ART), says Dr Firuza R Parikh, director of Assisted Reproduction and Genetics at a city hospital.
Dr Nandita Palshetkar, gynaecologist and infertility specialist, says, "This technique gives women an opportunity to slow down their biological clock by freezing their eggs till they are ready for conception. When they decide to get pregnant, the eggs are thawed, fertilised in-vitro and transferred back into the uterus."
Infertility specialist consultant Dr Richa Jagtap states, "Today's lifestyle tries to defy nature. Women choose partners late and this means they delay pregnancy. However, we can now do oocyte cryopreservation. The American Society of Reproductive Medicine removed the "experimental" label from the technique in 2012 and it has since been included in mainstream fertility practice."
Dr Parikh adds, "There are many women who cannot contemplate marriage in the near future as they are still looking for the right partner or have many compulsions like working their way through their careers. Freezing eggs is a woman's biological insurance against ageing. However, many women are complacent and believe that egg-freezing can be done at any age. They wait till they turn 40, but by that time, it is too late! Eggs are best frozen between the ages of 25 and 37. Women who can afford this option should not waste time."
The technique The patient is initially tested for HIV and Hepatitis B and C. Thereafter, the eggs are removed surgically and frozen — either by cooling down slowly or by vitrification i.e. fast freezing. Eggs frozen at a temperature of -196 degrees C in liquid nitrogen and liquid cryoprotectant ensure long-term storage. During this period, the woman can decide if she wants to use the eggs herself or donate them to help another woman get pregnant.
Recent studies have shown that egg-freezing by vitrification method increases conception rates. That's because the chances of the eggs surviving the freeze-thaw process is comparatively higher.
In oocyte cryopreservation, the eggs are harvested by a process similar to the natural cycle. The patient will be made to grow more eggs, with the help of hormonal injections, which are patient-friendly and can, in most cases, be self-administered. The eggs are later retrieved by a 10-minute procedure under short anaesthesia. The patient can resume normal life within a day. The eggs are cryopreserved using advanced vitrification process, which causes minimal damage to the eggs — they can be maintained for five years or even more. The duration of storage does not hamper egg quality.
The biologyA woman is born with all the eggs she will ever have. In fact, the strength of her oocyte reserve is finalised when she is in her mother's womb. This number promptly becomes half by the time of birth. The eggs lie dormant till hormonal activity starts at puberty. Each month, a bunch of eggs start their journey towards ovulation. Only the best are selected and the rest are discarded naturally. By the age of 37, there is a sharp decline in the egg reserve and the number steeply declines till the age of 40-plus, when there are but few good ones left.
Advantages of egg-freezing It's been proven advantageous in many situations. For example, chemotherapy or radiotherapy are highly toxic for the eggs. So, young cancer patients can freeze their eggs before treatments begin. Also, many women today delay pregnancy due to various reasons. Freezing eggs at an early age will help them start a family whenever they wish. It's even more important for women with a family history of early menopause, as the eggs start depleting at an early age.
Points to ponder- Approximately 2,000 babies have been born from frozen eggs till date.- Research shows that they have no increased rate of birth defects as compared to the general population.- There is no increase in the rate of chromosomal defects in embryos derived from frozen eggs.- Ideal candidates for egg freezing will be single women in their early thirties and those undergoing medication that hampers fertility.- It's important to freeze your eggs before their quality begins to decline, which happens after around 37 years of age. (With inputs from Dr Firuza R Parikh, Dr Nandita Palshetkar and Dr Richa Jagtap)
How many eggs can you store? While deciding the number of eggs to be stored is a matter of personal choice, it is advisable to freeze about 10 eggs. Most women under 38 years of age harvest 10-20 eggs per cycle. Out of the 10, only seven may survive the thawing process. Of these, only five or six may get fertilised. The best three or four embryos are transferred to women up to 38 years of age.
Did you know? - Eggs are stored in cryotanks or cryobanks, which are cylinders filled with liquid nitrogen. Each repository stores only one sample, so there are no chances of any mix-up. - Egg-freezing costs between `20,000 and `80,000. In Vitro Fertilisation (IVF) will cost anything from `80,000 to `1 lakh, without medicines (with medicines, this will go up to around `2 lakh).
