Caring about conception
If you're trying to get pregnant, you've likely
been inundated with advice on what you should be doing to increase
your chances of conception. Fertility specialist Dr Richard Fisher
looks at the options.
Most of us plan for events of significance in our lives.
Such relatively uncomplicated things like birthday parties and
holidays often consume the most planning effort. Buying a house
takes a degree of financial planning, but it always surprises me
how spontaneous the decision to buy a particular house can be.
Getting pregnant, likewise, should be a planned event, but the
vagaries of biology often make the particular timing difficult,
even if the intent is clear.
Unplanned and unwanted conceptions are clearly a social tragedy,
with significant risks to children conceived and grown in an
environment full of physical risk factors. Planned pregnancies,
however, are now coming under more scrutiny as well, as medicine
moves towards a further clinical and research sub-speciality of
peri-conceptional medicine. There is increasing recognition that
parents' behaviour and habits around the time of conception can
have significant short-and long-term effects on their fetus and
There is no greater gift parents could give their children than
healthy sperm and healthy eggs, and to reach this goal, you have to
understand the environment in which those gametes grow and in which
a resultant embryo will also be nurtured.
It is commonly stated that we live in a child-centred
society, and I daresay that most of us think we do. We can always
point at the exceptions as if they are not our problem. The
vulnerable in our society are so often children, and we as a
community owe them all a duty of care.
The recent debate about folate supplementation in bread to
help prevent neural tube defects like spina bifida points to our
ambivalence about this. Middle-class opposition to such
fortification was based around an argument about individual choice
and our ability to protect our own children by taking the
supplements we choose. It is so often not the children of the
middle class who are at major risk, however, for, with some
exceptions, those most at risk are born to parents who have poor
nutritional status, quite apart from a genetic predisposition. If
we are to protect those children, then we should bear some
community responsibility for this by accepting that supplementation
of bread with folate is a way in which we might significantly
reduce the risk for someone else's children, rather than care about
our own alone.
There is evidence that we now live in a society in which our
nutritional status is worse on average than it used to be. Like
those with poor nutrition, those who live in nutritional plenty are
now beginning to reap the adverse side effects of that. It is not
just the risk of Type 2 diabetes that is the problem, but being
overweight or obese affects the underlying chance of fertility for
both men and women. Recent studies from the University
of Adelaide have shown that couples having IVF had clinical
pregnancy rates which were significantly reduced, as both maternal
and paternal body mass index increased quite independently of each
other. Of particular interest in one of these studies was that
approximately 80% of all men in this unselected group were
overweight or obese, and this posed the question about what effect
paternal weight might have on the chance of natural
For overweight and obese women, not only did they have a smaller
chance of being pregnant, but the pregnancies which resulted had
more complications as well as more adverse effects on the newborn
in terms of growth, development and the rate of congenital
abnormality. Neural tube defects, heart abnormalities, and complex
abnormalities are significantly increased in the children of obese
and overweight women. If a medication had the same adverse effect
on fetal abnormality as obesity does, we would certainly ban its
Animal studies have shown that weight alone is not the
only determinant of outcome, but also the type of food consumed at
the time of conception is important. Animal work at the Liggins
Institute in Auckland has shown that mothers fed a high-fat diet at
the time of conception had babies who wentthrough puberty earlier
and had higher levels of total body fat and altered levels of sex
hormones. How well they were looked after or fed after birth had
little effect on those parameters.
Other work from the Liggins Institute has shown that sheep that are
underfed leading up to conception have lambs that are born
prematurely. Premature lambs then have significant risk of obesity
and Type 2 diabetes themselves as they mature. What is just as
disturbing is that their offspring - a further generation - are
also more likely to be obese and develop diabetes.
Intergenerational effects of problems in pregnancy are
likely to become more commonly recognised with continuing research.
Clearly, peri-conceptional nutrition is an area ripe for future
research. A well-rounded, healthy diet would seem appropriate,
although how to define this diet is difficult.
Our concern about healthy eating, however, often leads us
to irrational behaviour. Around 50% of couples presenting at
Fertility Associates are already taking supplements of some sort.
In the world of complementary medicine, marketing seems to trump
science on all occasions. With the exception of folic acid, there
is little evidence that supplementation of vitamins in someone
ingesting an otherwise healthy diet does little more than make
expensive urine. The concern that not taking supplements might be
harmful is seldom balanced by the question as to whether taking
them is actually harmful. There is evidence that high supplementary
levels of vitamin A in pregnant women is potentially harmful, and
vitamin A has been shown to be associated with an increased risk of
congenital heart defects.
A question has been raised about the use of vitamin E for the same
reasons, although the evidence is much less clear. The fact that a
vitamin occurs naturally and that in some specific people
replacement of inadequate levels of particular vitamins have
positive health outcomes does not mean that supplementing all diets
is necessarily beneficial. Developing a concept that both food and
vitamin supplements are drugs will be, I think, a significant
advance in ensuring that the environment in which conception occurs
is as healthy as possible. While we have printed warnings about the
health effects of adverse factors such as cigarette smoking;
perhaps it is time to issue a warning on supplements that says,
"There is no evidence that taking this supplement will do you any
Over the last decade, a considerable amount of data has become
available about sperm and sperm function. Recent data looking at
the fragmentation of DNA in sperm and its association with a
decrease in function has led to a search for effective treatments
in men whose sperm exhibits such abnormalities. The presence of DNA
fragmentation is correlated with oxidative stress, and the finding
that the use of some antioxidants can reduce the presence of
reactive oxygen species, which cause this stress, has led to
considerable research effort.
The extrapolation of findings in a small study, which showed men
who had poor sperm counts and motility in IVF cycles being treated
with micro-injection led to better pregnancy rates, has led to a
marketing explosion supporting the use of antioxidants in all men
trying to conceive. Although there is no data suggesting these
might be harmful, the people whom we think will benefit from the
use of antioxidants are those with a defined problem, and we have
no knowledge about whether otherwise normal men will be similarly
advantaged or disadvantaged.
The fear of "missing out", together with sophisticated marketing,
makes the use of supplements for "support" and "assistance" in
conception a fertile ground for exploitation. For some time it has
been known that vitamins C and E (both antioxidants) can alter
sperm function. There is limited data as to whether it makes a
difference to the chance of conception. There is no data at all as
to whether cheap products are any worse than an expensive product
with the designated use for supporting male sperm health.
The whole area of sperm function is very important and,
more than ever, focus is being placed on the male to see what we
can do about improving pregnancy outcomes. The production of
reactive oxygen species in abnormal environments may be the key to
deterioration in sperm function, and the use of antioxidants may
prove helpful in mopping these up. Antioxidants are found in foods,
particularly in highly coloured vegetables and fruits, but the
effect of improved nutrition in men, either in humans or in the
animal species, has not been subject to the same scrutiny as in
women. Oxidative stress, however, is known to be associated with
smoking and some dietary deficiencies, excessive alcohol
consumption and extremes of exercise. The way to resolve these
problems is certainly to remove the stressors rather than treat the
subsequent problem. Age and chronic disease also cause oxidative
stress, and although the latter may be alleviated, the former is a
Smoking cigarettes has long been suspected as a cause of decreased
fertility, and the increased incidence of problems in offspring.
There is now clear evidence. Not only does male smoking decrease
the chance of conception, it also increases the risk of miscarriage
in the partners of men who smoke. More recent evidence also shows
that women living in a smoking environment take longer to conceive
due to the effect of passive smoking, and that there is an
increased incidence of birth defects in their children.
Alcohol use in men also shows a correlation between the amount
ingested and the chance of conception in both men and women, quite
apart from its recognised effects in pregnancy.
So where does all this evidence leave us? Clearly, external
influences like smoking and alcohol are risk factors to avoid.
Being either overweight or underweight is undesirable in mothers
and may affect their offspring, and certainly being overweight in
men will reduce the chance of conception, and is probably
associated with an increase in congenital abnormalities in their
The influence of particular types of diet is likely to become much
clearer over the next few years. Our desire to do our best will
probably mean that we continue to consume large amounts of
unnecessary supplements, but it may take some time until we are
sure they are really safe.
The goal of healthy sperm and healthy eggs is one which we are
still some way away from achieving. We should change those factors
we can, steer away from the extremes of dietary advice and
practice, and eat as healthily as possible. We should not allow
ourselves to overmedicate with unproven supplements until we can be
more certain that they are truly beneficial, but embrace those like
folic acid which we are sure can be.
Getting pregnant need not be a military exercise, but careful
planning is likely to lead to the best outcome for our
Dr Richard Fisher (FCROG, FRANZCOG, CREI), together
with Dr Freddy Graham, established Fertility Associates in 1987
after previously starting up New Zealand's integrated infertility
medicine group at National Women's. He is New Zealand's foremost
medical spokesperson on matters of reproductive health, and has
been an advocate for better access to care for couples with
infertility throughout his career. He has four children and
is married to Leigh, without whom he could never have practiced
medicine with the enthusiasm and commitment he
As seen in OHbaby!
magazine Issue 9: 2010
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