Understanding IVF

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1. What is Preimplantion Genetic Testing (PGD/PGS)?
   
   PGD/PGS is a relatively new procedure in which embryos are tested for certain genetic conditions prior to being replaced in the womb. Couples can benefit when the woman is 35 or older, by testing for age-related chromosomal disorders, also called aneuploidy. Younger women with repeated unexplained miscarriages can also benefit from this test. The purpose is to select and replace only those embryos that appear to be chromosomally normal, so that women may increase the chance of conceiving, while reducing the probability of losing the pregnancy or carrying a chromosomally abnormal baby to term. PGS for aneuploidy can determine the presence or absence of a certain number of chromosomal disorders, but cannot detect genetic disease nor predict congenital malformation.
2. What is ovarian hyperstimulation syndrome (OHSS)?
   
   The single most serious complication that an IVF patient faces, apart from multiple pregnancy, is the risk of becoming seriously ill after being stimulated with injectable fertility medications. This condition is known as Ovarian Hyperstimulation Syndrome (OHSS) and reports suggest that 1 to 2% of patients who receive these medications may develop signs of hemoconcentration, weight gain, severe abdominal distension, ovarian enlargement and in severe cases even renal failure. The exact cause of this syndrome is still incompletely understood, although it is well known that the administration of Human Chorionic Gonadotropin (HCG) is the precipitating event which sets in motion the symptoms mentioned above and that OHSS is made worse by pregnancy! When there are more than 20 follicles developing and the estradiol level rises above 4000 pg/ml then there is a risk of moderate OHSS and with more than 30 follicles and estradiol greater than 6000 pg/ml there is an 80% chance of developing severe OHSS. In the past, the only way of avoiding severe OHSS was to withhold the administration of the HCG and cancel the IVF cycle.
   
   The patients most likely to develop OHSS are patients with menstrual cycles longer than 30 days or patients with irregular ovulation and menstruation. Age is also a factor, but OHSS can occur in patients over 40 years if more than 20 follicles are produced. We can therefore predict which patients are most likely to develop hyperstimulation based on menstrual history and we can also identify early during stimulation, which patients are producing more than 20 follicles. "Prolonged Coasting" is a simple procedure whereby the fertility medication is stopped at a very specific time, in patients that are at risk for OHSS. The correct time to discontinue the fertility medication is when approximately 30% of the follicles have reached 15 or 16 millimeters in diameter. The estradiol levels should be followed daily thereafter and they will continue to rise and when the estradiol level falls below 3000 pg/ml it is safe to administer HCG and proceed to egg retrieval.
   
   Embryo quality after coasting is better than the quality seen in non-coasted patients and the pregnancy outcome in patients who require coasting is excellent. It is important to restrict fluid intake to one liter of a sports drink like Gatorade per day for approximately 10 days after the egg retrieval.
   
   If you think that you are a high responder or have menstrual cycles that are irregular, make sure that your doctor is familiar with "prolonged coasting" it may prevent a cancelled cycle and also avoid causing ovarian hyperstimulation syndrome.
3. What is meant by the biological clock or ovarian reserve?
   
   A female fetus starts out with more than one million immature eggs and this number decreases steadily so that at the time of puberty, there are approximately 200,000 eggs remaining in the ovaries for future ovulation. Many eggs are recruited each month but in a natural cycle only one egg matures. Menopause refers to the time when all viable eggs have been used up and this generally occurs in the mid to late 40's. The biological clock therefore refers to the time starting with puberty and ending with the menopause during which the number of eggs decreases steadily. As a woman approaches menopause, the ovaries become more resistant to stimulation producing fewer eggs than they did in the years before. For some women this ovarian resistance can start in the 30’s and even occasionally in the teens and early 20's.
   
   There are a number of ways of estimating ovarian reserve; the most common is to measure the FSH and the estradiol on the second or third day of the menstrual cycle. An FSH level over 10 and or an estrogen level over 70 suggests the onset of ovarian resistance.
4. What is surrogacy?
   
   There are two types of surrogacy. The first, Classical Surrogacy, involves the insemination of a surrogate with the sperm of the father-to-be. The surrogate contributes her genes to the make-up of the child, carries the baby to term, and then gives up the child for adoption to the Intended Parents at birth. At Zouves Fertility Center, we only perform Gestational Surrogacy, where the woman who carries the child does not contribute her gametes to the equation. The eggs are obtained from the genetic mother and the sperm from the genetic father. The resulting embryos are incubated in the uterus of a surrogate who undergoes prior hormonal preparation. At birth, the surrogate gives the child back to the Intended Parents. Depending upon the State where the birth takes place, there may be issues of custody and the Intended Parents might have to undertake formal adoption procedures to acquire legal custody of the child. In some states, the name of the Intended Parents rather than the surrogate (the birth mother) will appear on the birth certificate. However, regardless of legalities, in Gestational Surrogacy, given that the eggs are not supplied by the surrogate, there can be no real debate as to who the rightful parents are.