The research about the effects of delaying marriage and childbearing is sobering, particularly to middle-aged women whose biological clock is running down despite the advances in medical technology that are pushing back the age at which women may conceive. There is the growing evidence about the deterioration of the quality of a woman’s eggs as she ages. Despite all that medical science can do, it is not uncommon for middle-aged women to face difficulties in conceiving, especially among those who have had abortions or whose tubes have been scarred by infections. Fertility treatments have benefited many women, but they can be costly and are not without problems. More and more women are having their first child after their 35th birthday, especially married women, and a great many of them have used fertility treatments to accomplish this.
An analysis of 20 years of mother-child data from some 79 million birth certificates reveals some important facts about middle-aged pregnancy.
From 1985 to 2004 the percentage of first births among married women accounted for by those 35 and older rose from 3.4 percent to 12.2 percent. Of these births, the share of plural births increased from 1.5 percent to 5.7 percent. There was a small increase in the percentage of plural births to married women 20 to 34 years old but not nearly as great as that of the 35-and-older women; the result was that the rate of plural first births for married women 35 and older increased from 1.3 times the rate for 20-34 year olds in 1985 to 2.4 times the 20-34 year-olds rate in 2004.
Women who delay marriage and childbirth often require the use of fertility drugs if they desire children; these treatments frequently increase the likelihood of plural births (the majority of which produce low-birth-weight babies). Women who follow this path need to know and fully absorb all of the facts about the prevalence of the associated pre-term deliveries and low-birth-weight babies and what this implies in terms of health risks to the child both as an infant and on through childhood. “The weight of the newborn is an important predictor of future morbidity and mortality. For VLBW [very low-birth-rate] infants, the risk of dying in the first year of life is nearly 100 times that of normal weight infants; the risk for MLBW [moderately low-birth-weight] infants is more than five times higher than that of heavier newborns.”
A delay in childbearing into the age range 35 and up of married women, by itself carries a moderately higher risk of delivering a first-born infant with low birth weight (a one-third increase from 6 percent to 8 percent when the infant is not a plural birth). But if that first birth is a plural birth (twins or more), the risk of having low-birth-weight infants is nearly 9.5 times as great as that encountered by a married women 20 to 34 years old having a single birth (57.4 percent as compared with 6 percent). The situation for unmarried women is much the same: delaying the first birth increases the risk from 8.5 percent to 12.7 when the infant is not a plural birth with the rate going to nearly 60 percent when the infants are delivered as part of a plural birth.
These sobering realities about middle-aged pregnancy stand in sharp contrast to the glowing picture of the young woman who flaunted with such abandon and enthusiasm the fact that she was most definitely expecting, in every sense of the word. When I think back on her brashness in light of the realities of middle-age pregnancy, I am a bit more forgiving of her behavior; her appearance at that meeting is one of those occasions when the recklessness of youth deserves, if not a pass, at least an indulgent smile.