The long and short of pregnancy intervals
By Reeta Raman, TODAY

SINGAPORE: When intervals between pregnancies, that is the time
lapse between the delivery of the last child and the conception of
the subsequent child, are shorter than 18 months and longer than 59
months, there are increased risks of low birth weight, small size
for gestation age - measurement of time inside the uterus - and
pre-term birth, according to an article in the Journal of the
American Medical Association (JAMA).
Researchers analysed studies published between 1966 and 2006 to
examine the association between birth spacing and the risk of
adverse peri-natal - the period immediately before and after birth
- outcomes.
The study discovered that infants of mothers with pregnancy
intervals longer than 59 months had a 20 to 43 per cent higher risk
of adverse outcomes.
The study also found out that in particular, inter-pregnancy
intervals shorter than six months and longer than 50 months, about
four years, were associated with an increased risk of foetal and
early neo-natal death. Neo-natal death refers to death of the baby
soon after birth. This association, however, is less clear.
There are a few explanations to comprehend the association between
long and short inter-pregnancy intervals and the risk of adverse
peri-natal outcomes, said Dr Law Wei Seng, registrar, department of
general obstetrics and gynaecology, KK Women's and Children's
Hospital (KKH).
For instance, one theory behind a short inter-pregnancy interval
and unfavourable peri-natal outcome is that a mother who had just
given birth would have poorer maternal nutrient stores to provide
for her subsequent baby. This is because there is insufficient time
to recover from the stress of her previous pregnancy before being
subjected to another, said Dr Law.
Along the same lines, it is believed that the association with a
long interval between pregnancy and unfavourable peri-natal outcome
is that after delivery, a woman's reproductive capacity gradually
declines, and eventually becomes similar to women who have never
delivered before.
The authors of the study hope that their findings would encourage
doctors to advise women on the benefits of delaying a subsequent
pregnancy for approximately two to five years to improve the health
of both mother and the next infant.
While the study is well-written, there are some limitations
concerning the quality of the original data such as the differences
in defining inter-pregnancy interval, said Dr Law.
"It may be too early to comment on the validity of this study
unless more information can be provided to explain the mechanisms
by which birth spacing might improve the health of mothers and
their children," he said.
So the long and short of the study: The ideal interval between the
delivery of the last child and the conception of the next child
should be between one-and-a-half to two years, a view that Dr Law
shares. He said: "Delaying conception for more than two years after
the last delivery should be weighed against the risks that come
with the mother's increasing age." - TODAY /dt
Copyright © 2006 MCN International Pte Ltd
Source:
http://www.channelnewsasia.com/stories/health/view/208539/1/.html