Biological Clock: A Truth or A Myth

You must have heard the word “biological clock” from your your grandmothers, in-laws and of course the aunties in a social gathering who frequently asks about the “good news”. This is the story of most married women aged below or above 30! With so many celebrities giving birth in their late 30's and 40's and with technological advancement in the field of reproductive science we can lower our guards. But the question of biological clock still lingers in our mind. Is there much truth in it or is it just a myth?
Dr. Vijaya Krishnan is the only Indian Certified Professional Midwife (CPM), and the co-founder and Director of Healthy Mother Sanctum, Natural Birth Center, has answers to your queries and is here to quell your worries.
There is a lingering debate that biological clock in women is ticking and that they can't have children after a certain age, is it true?
There is no straight answer to this question. But generally, women can conceive as long as they are fertile. Chronological age and biological age are different though. A 38 year old woman, who has taken good care of her health, eats cleanly, works out regularly and who is overall active, may have the biological age of a 30 year old. Similarly, a 25 year old who is obese, eats fast food 4 times a week, never works out, and is sedentary, will have the biological age of a 40 year old.
The biological clock and its relation to reproduction first surfaced in 1978, when Richard Cohen wrote an article in the Washington Post about how women were juggling jobs and a family – he wrote “the clock is ticking for the careerwoman”. Now, the popular use of the biological clock is used to refer to the maternal instincts of women, particularly as they grow older. It is also used to talk about “maternal instincts” and “longing for a baby” – all these can happen as early as in the woman’s 20s. Currently however, this term emphasises the woman’s mythical biological age ‘window of opportunity’ to have a child; and the whispers start the minute you start approaching 30.
How does age affect fertility?
Women are born with the total number of eggs that they will ever release. This is called the ovarian reserve. Every menstrual cycle (or alternate cycles for some women), the woman will release an egg, which sits and waits in the fallopian tube for a sperm to fertilise it. If fertilisation happens, and hormones are optimal, the woman will go onto become pregnant. If there is no fertilisation, that cycle ends with menstruation.
There is no concrete number at which fertility declines but it’s a fact that the ovarian reserve depletes with age. Age is the most important determinant of fertility, and though the depletion varies from woman to woman, it rises steeply after 35. It is advisable to visit a gynaecologist, if after 6 months of trying to conceive, you have still not become pregnant. This is true for a woman of any age, who is trying for a baby.
Being healthy, and exercising regularly, and not smoking increase your chance of getting pregnant, even if you get older, but still there will be certain increase in inherent risks as you age.
Is there a certain age within which a woman should plan a family and why?
As the woman grows older, so do her eggs. The chances of having chromosomal abnormalities and having a child with Trisomies such as Down’s Syndrome, increases dramatically after the age of 35. If the overall risk is <1:10,000 and age predicted risk at 25 years is 1:1500, it will increase to 1:400 at 35 years of age.
Chances of miscarriages and stillbirths also seem to increase as the age increases, partially because of lifestyle diseases. However, it is also partially due to increasing hardening of arteries, which then sends decreased blood flow to the placenta, which is the nourishing organ for the unborn child. Thus, the rate of early or first trimester pregnancy losses is also showing increasing rates, as women age.
Another issue that is surfacing fairly commonly these days is hormonal problems. Coupled along with improper sleep or wake cycles, sedentary lifestyle, and age playing its role, hormonal issues like Poly-cystic Ovarian Disease can cause immense barriers for conception.
Finally, even if the woman gets pregnant, after 35 years of age, the chances of having problems like gestational diabetes, gestational hypertension, or even hypothyroidism during pregnancy increase, as pregnancy puts increased stress on the woman’s physiology.
All things considered, it would be advisable for women who want children, to try for having their first baby, at least in the early 30s.
Do men have a 'ticking' biological clock too? What is their maximum age limit?
While men can apparently feel the clock ticking too, and a body of research suggests that sperm count diminishes with age, but they do not feel the biological urgency, the social pressure of having a baby and the sense of being incomplete if you don’t have one.
Women bear the brunt of social pressure unlike men to have children within a certain age. In what way can a woman prolong her fertility window?
Again, being healthy helps. We know that trying to minimise environmental stresses and healthy eating and keeping yourself fit and being in the optimal weight range improves the hormonal aspects of fertility. However, there is no substitute for your ovarian reserve. So, unless you have frozen your eggs or are looking at IVF or surrogacy, conceiving a child after 40 will require guidance by a health care professional.
What are the medical tests to find out the time limit within which a woman can reproduce?
You can find out how much ‘time’ you have to make a baby by initiating an Anti-Mullerian hormones (AMH) levels check. Processed in the form of a blood test, it gives you information about the amount of hormone produced by your eggs. However, a single AMH test cannot reveal the whole fertility picture. Only a thorough check up with a gynaecologist or fertility specialist enables to get the full picture of your fertility. Even then, the variables can be many.
What are the birth complications that can happen if a women gives birth in their late 30' or 40's?
Other than the increased risk of chromosomal disorders, and the increased risk of developing lifestyle diseases during pregnancy, there are no other major complex issues. If the woman is otherwise healthy, she will have a healthy pregnancy and can have a natural childbirth at age 40, just as much as she can at age 30.
The social pressure creates more pressure on women then physical limitations, what are the consequences a women can face if she gives birth “late”?
Not much in my opinion. The older mother is more mature, and is able to balance her work-life pressure better. That said, there can be no generalisations in this regard. Taking the responsibility to have a child is immense, whether you are 20 or 40, and you need to be prepared for it physically, emotionally and psychologically, so as to give the best possible environment for your child to grow up in!
For Appointments : Dr. Vijaya Krishnan, CPM, DPT, LCCE, FACCE Certified Professional Midwife Director, The Sanctum Natural Birth Center, Hyderabad