A woman’s age affects her fertility

KOCHI: Age is no barrier to achieving many things. But it can reduce the chance of a woman getting pregnant and having a healthy baby. A woman’s age is the single most important factor affecting her fertility.

Societal shifts, triggered by a greater focus on education and career, have resulted in a trend toward delayed childbearing in women. Between 1990 and 2010, the percentage of first birth in women more than 30 years of age has increased six-fold. Along with the increase in maternal age, there has been an expansion in the number of women attempting to conceive at an age when the probability of conception is significantly decreased.

The proportion of women who remain childless increases progressively with increased age at the time of marriage, 6% at age 20 to 24 years, 9% at age 25 to 29 years, 15% at age 30 to 34 years, 30% at age 35 and 39 years and 64% at ages more than 40 years.

Causes of age-related infertility

Women are born with all the eggs to they will ever have. As the woman ages, her eggs age with her, diminishing in quantity and quality. Furthermore the risk of miscarriage and chromosomal abnormalities increases with increasing maternal age. Ageing is also associated with an increase in disorders that may impair fertility such as tubal disease, uterine fibroids and endometriosis. Reproductive ageing is the natural process of declining fecundability as women progress through the stages of puberty, fertility, the menopause transition and menopause.

However, the rate at which a woman moves through these stages can vary per individual. Therefore woman of the same reproductive age can be at different stages in their reproductive lifespans. Because of this age-related decline in fertility, an important consideration is given to women planning or attempting to conceive in their later reproductive years.

The figures about women, age and fertility

Starting at about age 32, a woman’s chance of conceiving decreases gradually, but significantly. From age 35, the fertility decline speeds up. At 30 years the chance of conception in each month is about 20%. At 40 years it is around 5%. Apart form the risks of infertility, the risks of pregnancy complications also increases as the woman’s age progress.

Is Paternal age a concern

Men can remain fertile for much longer than women. Even though male fertility also declines with age, it tends to happen gradually for men. But as in women, even though many men remain fertile into their 50’s and beyond, the proportion of sperm disorders also increase with age.

Treatment options

Infertility treatments cannot fully compensate for a decline in fertility by age. Therefore even though infertility treatments are started only after one or two years in couple with no other fertility issues at age less than 30 years of age, the current recommendations are to proceed with an evaluation for infertility after 6 months of attempted conception in a woman more than 35 years of age

In general, an infertility evaluation includes determination of ovulatory status, tests of ovarian reserve, evaluation of tubal or uterine anatomy and semen analysis. If the tests are normal, then empirical treatment is usually undertaken with controlled ovarian hyperstimulation, intrauterine insemination or in vitro fertilisation. However, these options are often limited by the woman’s age-related potential for reproduction. Even after IVF and ICSI, the likelihood of successful ongoing pregnancy is compromised by age. After the age of 30 years, the probability of ongoing pregnancy decreases by about 1.5 % per year.

Another potential option for patients with advancing age is the option for elective oocyte or egg freezing.
To conclude, with the societal shift towards delayed childbearing, it is important to remember that age is still the best marker for reproductive potential. Although fertility declines with age for both men and women, the risk of infertility (ie failure to achieve a successful pregnancy after 12 months of attempted conception), has a stronger correlation with maternal age. Also, pregnancy at an advanced maternal age has increased risks to both mother and fetus.

So to have a child before the age of 30 or at least before the age of 35 should be a priority of every woman who wishes motherhood and evaluation of causes for infertility should be considered by every couple who have failed to conceive after 12 months of attempt conception.

Dr Sneha Ann Abraham,Infertility Specialist,KIMS Hospital, Thiruvananthapuram The views expressed by the author are her own.