Sunday, April 17, 2016

Older Moms Have Smarter and Taller Kids

Summary: Midwives have been saying this for ages, and researchers of the related field too have reported that the children delivered by older women are at greater health risks. Childbearing at older ages is understood to increase the risk of negative pregnancy outcomes such as Down syndrome, as well as increase the risk that the children will develop Alzheimer's disease, hypertension, and diabetes later in life.

It is a Declaration ..... Not a Debate

A research reported in journal Population and Development Review, put this old age observation in a fix. It suggests children of older mothers are healthier, taller and obtain more education than the children of younger mothers. The main reason is that in industrialized countries educational opportunities are increasing, and thanks to advancement in medicine science, people are getting healthier by the year. In other words, report supports old age pregnancy and birth.
Methdology: Researchers used data from over 1.5 million Swedish men and women born between 1960 and 1991 to examine the relationship between maternal age at the time of birth, and height, physical fitness, grades in high school, and educational attainment of the children. Physical fitness and height are good proxies for overall health, and educational attainment is a key determinant of occupational achievement and lifetime opportunities.
In their statistical analyses, researchers compared siblings who share the same biological mother and father. Siblings share 50% of their genes, and also grow up in the same household environment with the same parents.
1. Women in the developed world are having children at later ages. Mean age at first birth, which has increased in each of the 23 OECD countries since 1970, now averages 28 years.
2. Advanced maternal age is associated with increased risk of poor perinatal outcomes and increased risk of mortality and cancer in adulthood. The research documenting these negative outcomes, however, neglects the potential benefits of being born at a later date.
3. Delaying parenthood means that the child is born in a later birth cohort. This is beneficial, since form any important outcomes related to health and educational attainment, long-term trends are positive.
4. Researchers find that the total effect of increasing maternal age-which includes individual-level factors such as reproductive aging and changing social resources, as well as the positive impact of improving macro-level period conditions-is consistently positive. This is true even in cases where the individual-level effect is negative, because the macro-level positive trends more than offset the negative effect.
5. Researchers found that when mothers delayed childbearing to older ages, even as old as 40 or older, they had children who were taller, had better grades in high school, and were more likely to go to university.
Conclusions: The authors concluded as “For example, a woman born in 1950 who had a child at the age of 20 would have given birth in 1970. If that same woman had a child at 40, she would have given birth in 1990. Those twenty years make a huge difference. A child born in 1990, for example, had a much higher probability of going to a college or university than somebody born 20 years earlier. Moreover, the benefits associated with being born in a later year outweigh the individual risk factors arising from being born to an older mother. We need to develop a different perspective on advanced maternal age. Expectant parents are typically well aware of the risks associated with late pregnancy, but they are less aware of the positive effects".
Article Citation: Barclay, K. and Myrskyla, M. Advanced Maternal Age and Offspring Outcomes: Reproductive Aging and Counterbalancing Period Trends. Population and Development Review 2016, 42(1), 69-94. (free copy)
Maternal-Age Stats from the Study: In 1968, approximately 75 percent of all births were to mothers aged less than 30, and fewer than 10 percent of births were to mothers aged 35 or above. Over a 45-year period childbearing at later ages at all parities has become more common; by 2013 approximately 60 percent of births were to mothers aged 30 or older, and 5 percent to mothers aged 40 or older. There are many reasons for the increase in the mean of maternal age at birth over these years. Much of the fertility postponement has been attributed to the use of the contraceptive pill, the expansion of career opportunities for women, and increasing economic uncertainty.