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About Gametes

  • Why does sperm have to be stored for six months quarantine period?

    The use of donor sperm is a regulated activity and without being registered for HFEA a center cannot offer such a service. Procuring sperm for the purposes of treatment requires the center to follow stringent method that satisfies scientific as well as ethical issues. The existence of a quarantine period is important for safe guarding against infections such as HIV or hepatitis B which have a long “incubation” period. However the NAT tests used advanced techniques of identifying the RNA/DNA components of viruses causing the above infections and thus are detectable very early in the blood, without having to wait for the incubation period. After an identified donor has given his last sperm donation sample, we wait for six months to do the final infection screening tests. The first infection screening test ahs happened when the donor first attends the clinic and has been counseled and founds the suitable for donation. If this test shows infection, the donor will not be used for the purpose of sperm donation. By repeating the tests six months after the final donation, we are assured that he was not in the incubation period when the samples are given. We can argue that most couples come together and even think of having babies do not subject each other such stringent scientific tests before agreeing to start a family. However the professional argument that such extra stringent diligence be shown wherein we have the opportunity to do so, when we have approached the problem in scientific manner rather than emotional manner, is the time effort and expense well worth. We couldn’t agree more. The nucleic acid tests (NAT) do not have to wait for the six months incubation period because a single test will be positive even if the prospective donor has been exposed to HIV or hepatitis B infection a few days prior. The circulating viruses and the nucleic acids are detectable by the NAT test which is highly sensitive. It doesn’t need the viruses then grow in the body and develop an immune response creating antibodies which is what normally gets checked in the standard screening tests. NAT tests are slightly more expensive but because they save the couples time, most couples will think it’s well worth the extra cost. Besides if the donor agrees to allow the center to use a sperm to treat other women, then the screening cost can be shared and thus the expense greatly reduced.

  • What is egg freezing?

    Egg freezing needs the patient to go through half of the IVF cycle, upto when we collect the eggs but without creating the embryos. We freeze the eggs so that we could use them as a later date when she desires a pregnancy. Last year the American Fertility Society advised that the success of egg freezing has improved so that it should no longer be seen or advised as an “experimental” procedure. Historically as late as 5-10 years ago, egg freezing was not a commonly available and a very successful treatment. These two factors always are each other’s cause and effect. Most new procedures in the family of IVF treatments will go through the initial years of improvement at the end of which they become more mainstream. The structure of the egg is such that it is not very easy to freeze it. This is in contrast with freezing of sperm which has been successfully done almost thirty years before egg freezing became common. In the 1990’s when IVF as a service was barely is 10-15 years old, embryo freezing was avaible. We couldn’t freeze eggs in those days. In the following 10-15 years the technique of egg freezing has improved to the point nowhere it is regarded as a mainstream treatment. In the past if a young woman needed radiation or chemotherapy for breast cancer which was going to destroy her ovaries, we put her through IVF to get her eggs but then we couldn’t freeze them and hence we had to use donor sperm create embryos which were frozen. The woman could get the frozen embryos replaced when the treatment finished and she had been cured of her cancer and ready to conceive. There was obviously the compromise, that the embryo would have her genetic material but the father would be an unknown donor. This was the best we could offer a patient 25 years ago. In today’s world, oocyte preservation is so successful that we can offer it not just to women with cancer but even for “social” reasons wherein the woman wants to delay her fertility without compromising the quality of the eggs.

  • Why do we have to freeze the eggs? Why not the ovarian tissue?

    Research began on both these aspects and both have been successful forms of treatments however freezing eggs has been more successful and convenient than freezing ovarian tissue and making it work either in the laboratory or after the implantation a few years later.

  • What is the ideal age to freeze eggs?

    The quality of eggs of a woman undergoes serious deterioration excess by decrease in the success of IVF beyond the age of 28-30 years. We would recommend women of that age to undergo a couple of cycles of ovarian stimulation and oocyte retrieval to get a 15-20 eggs to freeze. When she feels ready to have a baby which could be a year or two later or 5 or evne 10 years later, she is most welcome to try natural methods herself. If however that doesn’t work, she always has the assurance that her own eggs has been preserved to use if needed. That reassurance in itself should create stress free approach to trying to start a family and I suspect would work far better than if the woman kept on worrying about her biological clock ticking and the ,limited time she have to conceive.

  • Advantages of freezing eggs - a summary

    a. If we freeze 10-20 eggs we know that statistically there is a good chance of making enough embryos to have a successful pregnancy or two. That assurance is priceless. b. Since the oocyte preservation has happened at the younger age, the risk of having a successful outcome is much higher than the real age of the same woman, when she has these embryos reinserted in her womb. c. Apart from success of an IVF attempt, the risks of having a Down’s baby or other numerical chromosomal abnormalities, is lower at the younger age so in some ways though the woman may be nearing her forties, the risk of having a Down’s baby is based on the age at which her eggs were frozen. d. If the woman conceives spontaneously having frozen of eggs before, she can always donate her eggs to a needy couple and again priceless, altruistic satisfaction.

  • Why has the success of egg freezing increased ?

    Freezing any gamete or embryo has several challenges the main being preventing the water within the gamete cell from crystallizing. If that were to happen, the cell membrane and other structure gets irreversibly damaged. Various sugars and proteins and such combinations have been used historically to prevent this from happening. Traditional wisdom means that the process had to be done slowly. In the late nineties radically different way of freezing gametes was tried which was called rapid freezing or vitrification. Over the last ten years that technique has further improved to the point where in the old method of slow freezing is practically less used and may soon become absolute. More than anything else it is a development in the art of vitrificaiton which has revolutionized the survival of oocytes after freezing. In the past the chance of oocyte surviving freezing and subsequent thying was less than 50%. Today the chance of this survival is above 90%. The process hardens the lining of the oocyte and thus necessity its ICSI than doing simple IVF.

What do various IVF drugs do?

  • GnRH –Anologues (Buserelini, Lupreide, Zoladex) GnRH is the hormone secreted by your hypothalamus which acts on the pituitary gland to secrete FSH which stimulates the growth of follicles in the ovary. In normal cycle the pituitary depends on feedback from estridial hormone from the ovary to decide when … which bring the better ovulation. In IVF cycle the estrogen levels go up and this could trigger the LH secretion quite early in the cycle. This would make a planned egg collection difficult or impossible. To avoid this pituitary needs to be quite and to do it needs a regular supply of GnRH analogues which effectively sets down the FSH and LH production of the pituitary glands. This hormone is neither swift (sineral) nor injected intradermal (lupride). Injection started typically on the 21st day of the period and it brings on down regulation of the pituitary in around ten days. Only when we confirm that the pituitary is quite and as a result grow well, do being the hMG injections. Links – How to take your GnRH-A

  • Gonadotrophins – FSH or a combination of FSH/LH (Gonal F, Humegon, Puregon, Menagon)

    This injection does the job done by FSH in the normal cycle. It acts on the ovary and stimulates follicles to start growing and then continue growing. The selection of number of follicles to start growing is called “recruitment”. FSH is needed for this as well as the increase in size which is called follicular growth. Follicle is seen as dark circular spaces and that is because of the fluid in the follicle which appears dark on ultrasound scans. The egg is growing within the follicle and there is a rough correlation between the size of the follicle and the maturity of the egg. The FSH dose is increased to reduce the based on the speed of the growth of the follicles. FSH injection is typically stopped on the day we give the hCG “trigger”.

  • HCG trigger (Pregnyl)

    This hormone is similar to the luteinizing hormone or LH. Its job is to prepare the follicle for rupture. The triggers starts an important phase of division of the egg needed for it to mature. HCG is typically given 35 or 36 hours before the proposed time of egg collection. Each follicle larger than 17 m or 18 mm in size are good enough to give an egg. HCG traditionally came from human placenta (hence its name Human Chorionic gonadotrophin). This the very hormone we check in your pregnancy test. If there are excessive follicles then the trigger injection can cause the precipitation of ovarian hyper stimulation syndrome. This in turn gets worse if the woman gets pregnant wherein the implanted embryo starts secreting its own hCG. Some clinics use hCG to support the corpus luteum which produces progesterone needed for the embryo to survive.

  • Progesterone tablets or pessaries (Cyclogest, Duphaston)

    Progesterone is a hormone secreted by the follicle after the egg is ruptured. This is the hormone which brings about special changes in the lining of the womb increasing the growth and activity of glands. It also relaxes the uterus and its important for the pregnancy to implant. The follicles from where the eggs are collected will secret progesterone as well but since we want the high level of progesterone we give the supplemented medications. Progesterone basically relaxes all smooth muscles of the body, mainly in the abdomen. So while it relaxes the uterine muscles, it also relaxes the colon. It is thus a common complaint that women feel a bit gassy, and constipated once these tablets start.

  • Anticoagulant Clexane

    Giving injections of anticoagulant Clexane is an empirical treatment to promote implantation and promote blood supply to the uterus. Better the blood supply to the embryonic chorionic tissue (precursor of the placenta) may help better implantation of the embryo. It is also known that in conditions where blood has a greater than usual tendency to clot, miscarriages happen. Giving heparin in low dose is a way to avoid these micro clots from happening and thus increasing blood supply to the nearly implanting embryo.

  • Prednesolone

    The big rate limiting step in test tube baby treatment is successful implantation of the embryo. It is known that the uterus identifies the embryo as a foreign body and there is a physiological reaction and secretion of steroids to blunt the immune-rejection reaction. Prednesolone tablets are immune suppressive and in some ways are expected to support the implantation of the embryos. These are given in relatively low doses and do not affect the body’s immunity generally. They are given only to tide over the period of implantation.