08 November 2004


"How realistic is it for a young woman today to expect to delay her childbearing into the fifth or sixth decade of her life while she pursues her career?"

Does that question sound like a dialogue from a science fiction movie? A doctor posed that question in this week's issue of the New England Journal of Medicine (which I just finished reading late last night, whew!). Doctor Linda J. Heffner, from the Department of Obstetrics and Gynecology, of Boston University School of Medicine, wrote a perspective article, titled: "Advanced Maternal Age --- How Old Is Too Old?" She tried to explore the possibility of safe pregancy and parturition among older women --- old because they were often busy pursuing their careers.

In the Philippines, there are two types of women --- the majority who either get married or pregnant at a young age (less than 20 years old) and the minority who either get married or pregnant at an older age (more than 30 years old). There's also a sub-classification of the latter, in which young women marry, but decide not to have kids in the first few years of marriage.

I will limit this post's discussion on the merits and demerits of advanced maternal age.

According to Dr. Heffner, there is only one desired outcome of pregnancy and that is to have a healthy mother giving birth to a healthy baby. In order to achieve this, it is necessary to study the effect of maternal age to the outcome of pregnancy by analyzing five specific factors that can negatively affect the desired outcome of a pregnancy. These are:

  1. Fertility - it has been found that fertility remains relatively stable through 30 years of age, at more than 400 pregnancies per 1000 exposed women per year, and then begins to decrease substantially. When women reach 45 years old, the fertility rate is only 100 pregnancies per 1000 exposed women.

  2. Miscarriage - defined as spontaneous pregnancy loss before the 20th week of gestation or around 5 months of pregnancy. Doctor Heffner found that 20-year-old women have about 10 percent miscariage rates. This increases to a high of more than 90 percent when women reach 45 and beyond. The high miscarriage rate contributes significantly to decreasing fertility among older women.

  3. Chromosomal Abnormalities - both advanced maternal and paternal ages contribute highly to increase incidence rates of chromosomal abnormalities like Down's syndrome, Marfan's syndrome, and achondroplasia. The specific culprit identified is deterioration in the quality of the ova with advancing maternal age.

  4. Hypertensive Complications - both chronic hypertension and pregnancy-induced hypertension complicate pregnancies by hindering fetal growth and may even be the reason why premature delivery options are made. This risk of hypertensive complications of pregnancy increases steadily with advanced maternal age and these complications become twice as likely among women 40 years of age or older than younger women. Also, the risk of giving birth to low-birth-weight (LBW) or preterm infants is increased among women in their 40s.

  5. Stillbirth - defined as the death of a fetus on or after the 20th week of gestation (5 months of pregnancy). This is about 10 times as common as sudden infant death syndrome among women with advanced maternal age.

[NEJM, November 4, 2004]

Career-oriented women might still want to argue that there are already findings that olders moms are able to deliver healthy babies comparable to their younger counterparts. Here's what Dr. Heffner says:

"....the beaming faces of these older moms as they pose for their photo shoots belie three unspoken truths about pregnancy.

"The first is that these perimenopausal women are typically screened for underlying health risks before they are accepted into donor-egg programs. The presence of hypertension, diabetes, or a history of cancer often precludes participation.

"Second, even among these healthy women, the rate of pregnancy complications is high. Pregnancy-induced hypertension has been reported in as many as 35 percent of women who become pregnant by means of donor-egg in vitro fertilization at 50 years of age or older.

"Finally", the cost of assisted reproduction restricts its availability to a small subgroup of the women who wish to bear children later in life. And it will be another 20 years before we can ask both parents and children from these perimenopausal pregnancies what it was like to face retirement and adolescence together.

"Recent advances in the ability to freeze eggs and the possibility that stem cells might some day yield oocytes may allow older women of the future to conceive children that are biologically their own, but these advances will not eliminate any of the concerns just described."

[NEJM, November 4, 2004]

It seems there are no merits in delaying childbearing after 30 years old among women who prioritize career over family life.

I know it's difficult, and I can be accused of making all these sound so easy because I'm a man...but hey, as I've always said in my previous posts: balance is the key.

Good luck, ladies. Stay healthy.

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