Q:
I am a 49 year old man considering becoming a father again. Should I be concerned that my age has an impact on sperm quality?

A:
Although there is no strong evidence that sperm suffer the same age related degradation as women’s eggs undergo, older sperm do cause their fair share of genetic problems, albeit in a much different way.

In contrast to females, who are born with all their eggs, men have no sperm when they are born. They don’t make any sperm until they reach puberty, when a prolific and persistent production begins. The average man makes about 250 million sperm a day: that’s about 6,000 sperm every time his heart beats. As a man ages, sperm production continues unabated, and there is no strong clinical or scientific evidence that production decreases significantly even in 70 and 80 year old men.

Since sperm production is so high, a man has to keep copying his DNA over and over again to make sperm. All this DNA copying leads to small mistakes, called mutations. If you remember that at its most basic level, DNA is a series of letters that make up recipes called genes. If the recipe is copied millions of times a day, mistakes inevitably happen.

Imagine having a cake recipe that has 3 cups of flour as part of the text. You photocopy the recipe for a friend. She photocopies your photocopy for a friend and so on. After multiple copies, your 3 cups of flour might start to look like 2 cups of flour, and suddenly your cake recipe doesn’t work any more.

These subtle copying defects cause a long list of diseases in the children of older fathers. Lesch Nyhan Syndrome, Polycystic kidney disease and Hemophilia A are among the most well known. For fathers over age 40, the risk of having a child with a disease-causing mutation is similar to the risk the mother has for a child with Down syndrome.

The biology of eggs and the aging of ovarian reserves are relatively well understood phenomena. As people gain a better understanding of how aging sperm can contribute to fertility complications, older couples will have better tools for planning their families.

Q:
It’s the New Year and my husband and I plan to get serious about exercising and shed 10 pounds. Since I am trying to get pregnant, is there anything we should know?

A:
Before you jump on that bicycle, be aware that there is considerable debate about the impact of exercise on fertility. A sudden and extreme change in your diet or work out regimen can have hidden consequences. Too strenuous exercise can lower estrogen levels and suppress the hypothalamus and pituitary gland, leading to irregular ovulation. Some women who exercise vigorously cease menstruating and ovulating all together.

In fact, because the research on even moderate exercise has been inconclusive, some reproductive endocrinologists advise their female patients to avoid all exercise that brings the heart rate above 110 beats per minute. This pretty much rules out jogging, aerobics and biking but not necessarily yoga and weight lifting.

Both women and men need some body fat in order to reproduce. (Although overweight women experience more hormonal imbalances because excess weight can cause excessive production of estrogen.) Body Mass Index measures the ideal level. Women who have a BMI of between 20 and 25 are most fertile.

As far as the male factor, the most important thing to remember is that sperm are very sensitive to heat. Taking saunas and hot tubs are enjoyable side benefits at many exercise clubs, but these heated conditions can greatly diminish healthy sperm counts. Bicycling is the main sport that is best avoided by men who want to maintain optimal conditions for reproduction.

Q:
I am 40 years old and have been experiencing unexplained infertility for about 2 years. I have been reading that PGD may help to improve my chances of success with IVF. Is this true?

A:
PGD, or Pre-implantation Genetic Diagnosis is a technique, when used in combination with IVF, that can help to determine if the embryos have what it takes to successfully establish a pregnancy. As women get older, there are more errors in the chromosomal make-up of eggs. The most well-known of these defects is Down Syndrome or Trisomy 21, a condition in which the fetus or baby has an extra chromosome number 21. Having a missing or an extra chromosome may make the embryo unable to develop much past a few days of life or may result in a first trimester miscarriage. PGD uses a DNA-binding technique to determine if there are a correct number of chromosomes in the embryo. To do this, embryos on Day 3 of culture (5-10 cells) undergo a biopsy to remove a single cell. The rest of the embryo remains in culture in the IVF laboratory. The biopsy cell is analyzed for the correct number of chromosomes. Currently, PFC with its cytogenetic partner, St. Barnabas Medical Center, tests for 9 chromosome pairs which represent the most common abnormalities seen and some of the most serious in terms of a potential birth defect. As this technology continues to evolve, we expect to be able to assess all 23 pairs. IVF with PGD cannot correct defects in chromosomes. It can only diagnose whether an embryo is abnormal for these 9 chromosomes. The embryo could still be abnormal for one of the other 14 pairs. PGD may decrease the possibility of a miscarriage due to abnormal chromosomes. It may allow for the selection of the embryos most likely to implant and cause a normal pregnancy. If a woman has a good number of fertilized eggs to work with, it may eliminate having an excess number of embryos returned to the uterus at any one time and may eliminate having frozen embryos that really are not genetically normal. Because the embryos will have been screened for some of the major chromosomal abnormalities, theoretically, the remaining embryos should provide a patient who is older a better chance at a viable pregnancy. Some studies have shown that the implantation rates (chance that any one embryo will successfully implant) can be doubled with IVF/PGD. Also, miscarriage rates have been reduced by one-half and the delivered pregnancy rate is increased. Women or couples interested in this procedure should discuss it with their Reproductive Endocrinologist. At PFC, we also refer our PGD patients for a special genetic counseling session in preparation for this process.

Q:
Hi – I have severe painful endometriosis, am 34, otherwise healthy and fit with one failed fresh IVF cycle and one failed frozen transfer. Is there anyway I can help the process of implantation? And could the endometriosis be preventing the implantation? Many thanks for your help.

A:
Endometriosis is the condition where tissue that forms the uterine cavity lining each month (and is shed as menstrual flow is now growing outside of the uterine cavity. This extra-uterine tissue is most commonly found around the ovaries, fallopian tubes, and outer layer of the uterus. In general, the negative affects of endometriosis are due to processes occurring in the pelvis. These negative affects make the pelvic fluid more hostile to eggs and sperm. Therefore, the negative pregnancy affects are limited to the processes that are occurring in this pelvic environment (egg bathed by pelvic fluid as they are ovulated, fallopian tubes bathed by pelvic fluid and impacting fertilization and early embryo development). The uterine cavity itself seems to be protected from these negative affects. For patients who need to proceed to IVF, we bypass the “pelvic environment” and all steps which would be occurring in the pelvis are now occurring in the laboratory (egg recovery, fertilization, early embryo development). The uterus is protected from the negative pelvic affects, so pregnancy rates are the same for endometriosis patients, as they are for other patients who need IVF. Exceptions to this would be patients with adenomyosis. Adenomyosis is a benign condition characterized by the endometrium lining growing INTO the muscular layer of the uterus, instead of just staying confined to the uterine cavity. The other exception is for patients who have endometriomas (endometriosis ovarian cysts filled with thick, dark brown blood). These can impact egg quality, so it is not uncommon that if you have endometriomas, it might take a few more IVF cycles than the average to achieve a successful pregnancy.

Isabelle Ryan, MD  and Joe Conaghan, Ph.D contributed to this post

Q:
If I use an egg donor, how many embryo transfers can I expect?

A:
PFC maintains detailed records of all treatment procedures and outcomes at our world class laboratory. Nevertheless, the answer to this question is not as straight forward as one might expect. Averages can be summarized, but there are wide swings in the first stage of this procedure – how many eggs a donor can produce. Also, the decision on how many fertilized eggs to implant and how many to freeze can be highly subjective according to the patient.

In 2002, each donor recipient received an average of 23 eggs. But one donor that year failed to produce even a single egg, whereas another donor produced a remarkable 52 eggs. Several successful pregnancies resulted from only a three egg retrieval, so remember, it only takes one healthy embryo to establish a pregnancy!

Once the eggs are retrieved, the fertilization rates are a tad bit more predictable, since most of the donors are in their 20s. In 2002, between 65% – 76% of the retrieved eggs from donors successfully fertilized, depending on whether the donated eggs underwent IVF or IVF-ICSI.

In the next step, the implantation stage, PFC transferred on average 2.3 embryos per patient, and froze on average 7.8 from a single donor cycle. (The average number for freezing would have jumped from 7.8 to nearly 10 if this figure had excluded the 20% of women who did not produce enough eggs for freezing.)

In other words, 80% of donor egg recipients had at least some remaining embryos to freeze after the initial implantation.

And the odds were good for those embryos that entered the deep freeze. Last year, 77% of all thawed embryos were transferred, an improvement over previous years.