There are both challenges and advantages to parenting at older age, writes Dr David Addenbrooke.
Women are increasingly delaying pregnancy until later life. The reasons for this are many and solid arguments could be made regarding the increasing average time in education and training, modern gender equality in professional careers and the increasing economic pressure for double incomes, particularly in urban centres.
There are clear advantages to starting a family with a higher level of emotional maturity and financial stability. The biology of aging however does not discriminate and it is also clear that fertility and pregnancy can become more challenging with time. The biological clock is ruthless when it comes to reproduction.
In obstetric circles, the move towards becoming an “elderly primipara” begins in the mid thirties.
The first reassuring statement to make about “advanced maternal age” is that outcomes remain generally good and no woman should be discouraged from undertaking a pregnancy based purely on age. There are a number of undeniable challenges though, which come largely down to three factors. Older eggs. Older bodies. Older minds.
Every woman is born with their entire lifetime supply of ova, dormant in primordial follicles until, with each menstrual cycle, a cohort are signalled to undergo meiotic division. With age, errors in meiotic division become more common and chromosomal nondisjunction produces imbalanced gametes more frequently.
Not only is this the basis for the ever-increasing risk of aneuploidy in embryos with advancing maternal age, but it is also a primary reason for higher miscarriage rates and lower conception rates with age. The stigma of age 35 came about because, statistically, the risk of aneuploidy in an embryo approaches the risk of intervention by amniocentesis after this age.
With modern technology we are now able to offer non-invasive screening, and more recently non-invasive diagnosis. All women, regardless of age, should currently be offered aneuploidy screening.
Once a healthy embryo is carried to the second trimester we must consider the additional challenges of the “older body” of the elderly pregnant. Many women are now embarking on pregnancy with pre-existing chronic conditions developed in their thirties or forties.
The older body may be less adaptable to the physiological changes of pregnancy. Conditions such as pregestational diabetes, thyroid dysfunction and autonomic disorders should all ideally be optimised prior to conception. Even in previously healthy women, physiological complications of pregnancy such as gestational diabetes and hypertensive disorders are more common with age.
It is good practice to offer women of advanced maternal age glucose tolerance testing at diagnosis of pregnancy, in addition to routine screening at 28 weeks. Early baseline renal and liver functions can also be useful to exclude pre-existing impairment.
A number of other conditions can be adversely influenced by the hormonal state of pregnancy. In particular, we must maintain vigilance for signs of venous thromboembolic conditions and breast cancer – both of which are higher risk with advanced age in pregnancy.
Moving forward to the third trimester, there are small but significant associations with age and placental dysfunction. Preterm birth, low birthweight, placenta praevia and placental abruption are all more common with age, though the absolute risk remains low. Importantly, the risk of unexplained stillbirth at term begins to rise after age 35.
Many units are now adopting a policy of early induction of labour, close to term, for women 40 and older. Alternatively, increased fetal surveillance should be offered to those women who wish to await spontaneous labour after term.
When labour occurs, the elderly primipara is more likely to have abnormal progress (particularly second stage) and statistically more likely to be delivered by Caesarean section, either planned or emergent. Vaginal birth should still remain the preferred mode of delivery when appropriate, regardless of age.
There are both challenges and advantages to parenting at older age. A few of the considerations include a generational peer gap and the potential for health burden with ageing parents during the child’s adolescence and young adulthood.
It is important to be mindful not to stigmatise women undertaking pregnancy at older age. I am often struck by how many women feel the need to justify their “pre-menopausal” pregnancy, despite the fact that these are often more considered and desired pregnancies than those of the younger cohort.
Despite the factors outlined above, it remains important to congratulate these women on their choice and support them with information in a non-judgemental manner.
