The trend toward older parenthood continues, with recent data from the Centers for Disease Control and Prevention (CDC) indicating that for the first time in three decades 2016 birth rates among women 30-34 surpassed those among women ages 25-29 in the United States. The average age for women having their first child is now 28 years old.
Parenthood might be delayed for a variety of reasons. Women are reaching higher educational levels and building careers. Social and cultural shifts are also in play. Perhaps there is for some a lack of childcare, inflexible workplace policies, or uncertainty regarding housing and household economics. For others it’s a matter of poor fertility and a need for help like IVF.
We’ve all heard about the “ticking biological clock” but does your 35th birthday represent a big biological milestone? Not necessarily. Women are delivering healthy babies throughout their 30’s and beyond. The age of 35 has become a marker where certain pregnancy risks become more worthy of discussion.
As a woman, you are born with all of the eggs you will ever have. Ageing means a declining number of remaining eggs, the quality of which also gradually declines. Fertility in men in similarly declining with age. Age-related factors simply make getting pregnant more difficult.
Certain genetic risks present more often in pregnancy as women age. One example is Down syndrome, that accelerates with maternal age.
Researchers have investigated why older mothers have higher risk of giving birth to babies with congenital anomalies characterized by abnormal chromosome numbers. In older mothers, recombination – a process in which pairs of chromosomes exchange genetic meaterial before separating – is less regulated. This can result in abnormal chromosome numbers of large chromosomal rearrangements.
A review published in the Canadian Medical Association Journal found that stillborn is 1.2 to 2.23 times higher for older women. Stillborn rates have been shown to be higher in women having their first child and even higher in first-time moms aged 35 or older. Unfortunately, the reasons that stillborn rate increases with maternal age is still unclear to the medical community.
Women age 35 and older are often recommended to be induced as they approach their due date because stillborn risk increases with gestation age.
Other risks to older mothers include an increased risk of gestational diabetes, breech positioning of the baby, and postpartum hemorrhage. There is also a higher probability of preterm birth and – oddly – either high or low birth weight.
But new studies indicate that low birth weight and preterm birth may not be due to the mother’s age and could be associated with individual circumstances and behaviors. Unhealthy behaviors, maternal stress, and even fertility problems may be the culprits.
The researchers who presented these findings say that women should not be concerned about their age when considering having a child, but should focus on making good behavioral choices for their own health, and ultimately that of the child.
Of course, women who delay pregnancy should be aware of the risks and proactive on optimizing their own health. Expectant parents are typically told about the risks associates with late pregnancies but are less aware of the benefits.
Children of older mothers have been found to have fewer behavioral, social and emotional difficulties, and some studies suggest being born later is also associated with being healthier and obtaining more education.
Most women aged 35 and older will have a normal pregnancy with few complications, and be able to deliver a healthy baby.