Susan writes:
"While height does not always predict pelvic size, studies done in
developing countries do show that significant stunting can lead to
increased rates of obstructed labor."
Just to clarify this post, Reynaldo Martorell's (and others') research on
the long-term consequences of malnutrition in childhood leading to stunting
(reduced height) in adult women and therefore to higher risk of
complications in childbirth refers only to *stunting*, not to merely being
short. These are two different issues.
If you are 4'10" tall as an adult because of genetic factors -- both your
parents and all four grandparents are very short -- but you and your parents
and grandparents all grew up with excellent nutrition and very little
disease, then you are not stunted, you are just short. And you are not at
higher risk of obstetric difficulties, because you have a perfectly normal
pelvis. You may have broad hips and a large pelvic outlet, you may have
narrow hips and a large pelvic outlet. Or you may have a small pelvic
outlet, regardless of the size of your hips. But you have the standard risk
of obstetric difficulties based on the size of your pelvic outlet, not the
broadness of your hips or your height.
If you are 4'10" tall as an adult because you grew up under adverse
environmental conditions, such as moderate to severe childhood malnutrition,
lots of diseases, contaminated water supply, no antibiotics, no
immunizations, emotional distress such as from civil war, etc. etc. etc. --
and if you and your parents and grandparents would all have been much taller
if you had grown up under better circumstances, then you are stunted. And
you are at higher risk of obstetric difficulties.
It is the mismatch between the underlying genetic potential for height and
the actual achieved height that qualifies as stunting. If you could have
been 5'6" from genetic potential and are only 4'10" due to poor diet and
disease and emotional stress, then you are stunted and may have a malformed
pelvis with a smaller pelvic outlet due to impaired growth of the pelvis
during childhood (which goes along with impaired growth in the long bones,
leading to short stature) and therefore a higher risk of difficulty in
childbirth.
If you could have been 4'10" from genetic potential and ARE 4'10", then you
are just genetically short.
It can be difficult to fully grasp the degree to which stunting affects
height -- many people think that the Vietnamese or the Mayans of Guatemala
are all genetically short. Some of them ARE genetically short, just as any
population has a range of variation in genetic potential in height, but most
of them are short due to generations of poor diet, disease, and war. When
you alleviate the bad environmental circumstances, the kids start to grow
more normally. The younger the kid when the environment is changed for the
better, the more like US growth standards they grow. It can take 2-3
genertions of good environmental conditions before the grandchildren and
great-grandchildren are able to achieve their full genetic potential.
Go to any mall in the US on a Sunday afternoon in a city where there are
lots of relatively recent immigrants from parts of the world where
environmental conditions are difficult and you can see the stair-step effect
known as 'positive secular trend' -- here is grandma, born and raised in
Guatemala (for example), at 4'10" tall; next is mother, born in Guatemala
and brought to the US in her early teens, at 5'2" tall, and here is
daughter, born and raised in the US, and already 5'6" at age 12 years. You
see this all the time. Grandma was stunted, mother was somewhat stunted,
daughter may still be a little stunted -- perhaps she'll end up 5'7" when
her genetic potential was for 5'8". The next generation will probably max
out the genetic potential, at last.
Kathy Dettwyler
_________________________________________________________________
Get your FREE download of MSN Explorer at http://explorer.msn.com
***********************************************
The LACTNET mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software together with L-Soft's LSMTP(TM)
mailer for lightning fast mail delivery. For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html
|
