folate at this crucial time can lead to serious malfor-
mations of the spine (spina bifida) and the brain (anen-
cephaly). Folic acid supplements (400mg/day) are
advised before conception and during the first 12
weeks of pregnancy because research has shown that
they can reduce the risk of neural tube defects such as
spina bifida by around 70%. Women who have
already given birth to a baby with a neural tube defect
should take a supplement that provides 5mg/day.
Extra folate in the diet is also needed throughout
pregnancy in order to prevent anaemia so pregnant
women should also eat a diet that includes plenty of
folate-rich foods (such as green leafy vegetables,
oranges and pulses such as beans and lentils) and
foods fortified with folic acid (such as fortified break-
fast cereals). In the United States and Canada, fortifi-
cation of flour with folic acid in recent years has
greatly increased folate intakes. Although the number
of babies born with neural tube defects has declined,
this can not be attributed with certainty to increased
folic acid intake.
Extra iron is needed during pregnancy, mostly in
the last two trimesters. Inadequate blood iron levels
causes iron deficiency anaemia which can make people
feel tired, irritable and less able to concentrate. The
risk of becoming anaemic is greater during pregnancy
and anaemic women are more likely to deliver a baby
of low birth weight and with poor iron stores. In the
US, most recommendations advise pregnant women
to take a supplement of 30 mg of ferrous iron as well as
eating a well-balanced diet. In other countries, such as
the UK, supplements are advised on an individual
basis where considered necessary. However, pregnant
women should eat plenty of iron-rich foods, such as
lean red meat, pulses, dark green leafy vegetables and
fortified breakfast cereals. Consuming foods contain-
ingvitamin Cat the same time as non-meat iron-rich
foods helps to enhance iron absorption. Examples
include having a glass of orange juice (a source of
vitamin C) with a bowl of cereal (containing iron) or
baked beans (containing iron) with a baked potato (a
source of vitamin C).
Vitamin Dis needed to absorb calcium from the diet
and an adequate supply is therefore essential for healthy
bones and teeth. A vitamin D supplement of 10mcg/day
is currently recommended for all pregnant women as
a precautionary measure. Vitamin D is obtained mainly
by the action of sunlight on the skin but is also found
naturally in eggs, meat and oily fish. Most fat spreads
are also now fortified with vitamin D.
DHA (docosahexaenoic acid) and EPA (eicosa-
pentaenoic acid) are types ofomega 3 fatty acids
found in oil-rich fish (e.g. mackerel, salmon, kippers,
fresh tuna, herring, trout and sardines). These are a
major constituent of the brain and retina and there has
been a lot of recent interest in their role in infant
development. Eating fish has been associated with a
lower risk of pre-term delivery and low birth weight.
DHA and EPA can be made in the body from a type of
polyunsaturated fatty acid called alpha-linolenic acid
but it is not known how efficiently the body does this.
Alpha-linolenic acid is found in oils (e.g. rapeseed,
linseed, soya, walnut oils), nuts (e.g. walnuts, peanuts),
grass-fed animals (e.g. beef) and green leafy vegetables
(e.g. spinach).Recommended dietary supplements
Apart from folic acid (400mg/day) and vitamin D
(10mg/day), other vitamin and mineral supplements
should not normally be necessary during pregnancy.
However, if dietary intakes are thought to be inad-
equate, then a low dose multivitamin and mineral
supplement can be taken as a safeguard. High dose
supplements should be avoided, particularly those
that containvitamin A (retinol). There are now a
number of specially formulated supplements available
for pregnant women, and those planning to conceive.The effect of diet on gastrointestinal
symptoms and morning sickness
Indigestion, heartburn and intestinal discomfort
are common, especially in late pregnancy when the
baby takes up more space and squashes internal organs.
Women usually learn by experience which foods to
avoid and this is unlikely to lead to any nutritional
problems unless it involves foods that are a major
source of important nutrients (e.g. all meat or dairy
products). Eating small meals, avoiding fatty and
spicy foods may help.
Women who are experiencing constipationor
haemorrhoids should increase the amount of fibre in
the diet, by increasing intake of starchy carbohydrate
foods, particularly whole-grain cereals and breads. An
adequate fluid intake is also important, along with
gentle exercise.
The causes of nausea and vomiting in pregnancy
are not fully understood, although it has been sug-
gested that changes in hormone levels or a heightened
sense of smell may be involved. The experiences of
individual women is very variable and can also differ
with successive pregnancies. Some women find that the
eating small, frequent meals can help to reduce nausea.
Carbohydrate foods (e.g. bananas, toast, cereal, dried
fruit), together with plenty of fluid are often the best
choice. Some research has suggested that vitamin B 6Pregnancy diet