SPEAKING OF SCIENCE
Bending biology for bearing babies
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Egg-freezing can give women more control over their fertility
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SPERM INJECTION: Frozen eggs are thawed back to room temperature and injected with a sperm to be grown into embryos.
DR. JAYASHREE Ramasethu works at the Children's Hospital in Washington DC, and is an expert in caring for premature babies. Many instances she cites are poignant.
Some `premees' are born so early that they weigh far less than a kilo. Equally worrisome is to look at the mother, who is in her early teens; and her mother (the baby's grandmother) is hardly thirty. Jayashree works hard and brings the baby to normal health.
Normal biology
These cases are subnormal. Normal biology would be when the baby arrives after the full term of nine months and weighs at least two kilos and a half, and the first child arrives when the mother-to-be is in her twenties.
Of course, biology allows puberty to start in girls, typically between the ages of 11 and 16, when they start their menstrual cycle in producing eggs and thus are fertile.
Teen-age mother
It continues until menopause, when egg production, and hence fertility, ends (usually between the ages of 45-55). Thus what we described above with the teen-age mother and her `premee' is a case of hastening biology.
What is also happening, increasingly in the U.S., is the other extreme of delaying biology. A report by Rob Stein in The Washington Post (May 13, 2007) describes how some American women "hedge bets by banking their eggs."
Intent on not upsetting their professional career paths, they postpone pregnancy and want to bear babies when they are in their forties or even later.
And an increasing number of clinics (138 at last count) are willing to help them by freezing their eggs in liquid nitrogen for decades.
When the lady is ready to bear a child, the frozen eggs are thawed back to room temperature and injected with the sperm of the father-to-be. These in-vitro fertilized eggs are grown into embryos in the clinic.
The healthiest embryos are selected and transferred into the uterus of the woman in another outpatient procedure. Nine months later, the baby is born. The lady has her career and her baby too. So goes the happy scenario, drawn up by the agency that markets these egg-freezing clinics.
Birth control pill
It says "In the same way the birth control pill gave women a whole lot of options, we think egg-freezing can do the same with the new generation of the women — giving them more control over their fertility and giving them more options."
What one lady, who has had her eggs frozen for a later-year motherhood, says summarizes the idea well: "This is kind of like my insurance policy. It gives me the alternative of still having my own child with my own gene pool."
Freezing eggs
Some women argue that freezing their eggs is a better ethical option, with no complications or dilemma as with embryo transfer.
This is true to a point, since many eggs are discarded on a monthly basis even in the normal course of ovulation. Some even argue that an egg (or for that matter, sperm) is "less alive" (if alive at all) than an embryo, which is a result of fertilization.
Even if it were `alive,' freezing does not kill it, but keeps it in suspended animation. Dropping its temperature by over 230 degrees drops its metabolic rates by a million-fold, and not stop them.
Recall that every drop of ten degrees drops the rate of many biochemical reactions by half.
New life
And if we accept sperm freezing for later day use, egg banking should not pose any newer problems. After all it is only when sperm meets egg and fertilizes it can a new life begin.
Yet there are other issues about egg-freezing that worry people. The most obvious is one of the greater vulnerability of eggs compared to sperm and embryos.
Advances in cell biology and technology, though, will be able to tackle this problem soon enough. With that, the costs should also drop from the current $12,000 per freeze, plus $ 400 per year storage fee.
Sociologically, the question being asked is why employers should not provide a more family-friendly work environment, so that baby rearing does not have to hinder the career path.
(Happily enough, the Indian Government has a policy and special funds for their agencies and offices to set up on-campus crèches and baby care centres. We at the CCMB - IICT campus at Hyderabad put up one such over a decade ago, which has since grown larger).
As the Professor at Vassar College has said: "I'd like to see us focusing on solving that rather than taking women into a risky medical procedure."
Unorganised sectors in India, such as the construction industries, leave the poor mothers to their wits. See the number of nursing mothers on site next time you pass by.
Biological health
Many others worry about the health, in particular the reproductive biological health, of women above 40, who would have the embryo implanted in themselves and carry it full term to deliver the baby.
And then, of course, there is the issue of demographic shifts when mothers in their 40s and 50s have their first child, at a time when traditionally women have their first grandchildren.
Born infertile
Then there is the bizarre story, reported in the same Stein report, of a Canadian mother who has frozen her eggs in order to give them to her 7-year-old daughter who was born infertile.
The girl could eventually give birth to her own half-sister! Another equally bizarre one is the possibility of shipping eggs across the world. Rather than adopt a child, would one adopt eggs?
New techniques
Tradition and conservation are challenged by newer techniques and approaches. Recall that Louise Brown, the first test-tube baby ever, is now 25 years old.
She heralded the era of test-tube babies born out of in-vitro fertilization, and since then there have been thousands and thousands more.
If one of them decides to freeze and bank her eggs for child-bearing later on, should that raise an eyebrow?
Would we agree with Stanford's William Hurlbut, who says: "I think our society needs to acknowledge the physiological constraints on women's fertility and get back to a more natural timing of child bearing," or would we contest the words "physiological constraints"?
D. BALASUBRAMANIAN
dbala@lvpei.org
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