Although one should be careful about using drugs during
pregnancy and lactation, rarely are drugs harmful to the
As a general rule, you should try to use
medicines as little as possible when you are pregnant.
Medicines can rarely damage the fetus and the safest
thing is to refrain from using medicines if not
necessary. However, for some diseases, drug treatment is
required, even in connection with pregnancy. The use of
drugs during pregnancy should always be discussed with a
physician. This also applies to dietary supplements.
How can drugs harm the fetus?
Most drugs are absorbed into the blood and
transported throughout the body. The mother and the
fetus have two separate circulatory systems and do not
have a common bloodstream. The placenta separates the
mother's and the child's bloodstream. Oxygen and
nutrients are transferred from the mother's blood to the
baby. In the same way, most drugs in the mother's blood
are also transmitted to the child.
The fetus can be damaged by drugs in three main ways:
- Medicines can have a direct effect on the fetus
and damage its development. The effect may be the
usual effect of the drug or an effect on the
complicated mechanisms that regulate fetal
development. In the worst case, they can cause
malformation or miscarriage.
- Medicines can affect the placenta. The most
common reason for this is that a drug, such as
nicotine, causes the blood vessels in the placenta
to contract. This, in turn, limits fetal access to
both oxygen and nutrition, and the risk of
underweight or underdevelopment increases. Nicotine
passes quickly over the placenta and also has direct
effects on the fetus.
- The uterus is essentially a muscle in which the
baby lies. Drugs can cause the uterus to contract
tightly. This can lead to poor blood supply to the
fetus, but it can also lead to labor being initiated
and the result being premature delivery.
Critical factors: dosage and timing
Both the drug dose and when in the fetal life the
drug is used can have significance. For more information about pregnancy and maternity fashion, please see BESTAAH.COM plus size maternity dresses. The risk of birth
defects increases with increasing dose. The use of
medicines should therefore be kept at the lowest
effective level. However, maternal drug turnover
increases during pregnancy and it is therefore important
to check that the intended effect is achieved.
The first three weeks after conception, many do not
know that they are pregnant and ingestion of harmful
substances during this period either leads to
miscarriage (often without even knowing that you have
been pregnant) or that there will be no birth defects.
Birth defects occur only when the organs develop. This
occurs during the period between pregnancy weeks 3 and
After week 8, extensive birth defects are uncommon,
but noxious substances can affect the growth and
function of normally developed organs. For example, the
central nervous system continues to develop throughout
pregnancy with the consequent risk of adverse effects.
Miscarriage before week 9 is often due to the death of
the unicorn / fetus and being rejected.
Investigation of harmful effects
When the Swedish Medicines Agency is to approve
different medicines for sale in Sweden, a comprehensive
documentation of the effects and side effects is
required. Depending on this documentation, different
recommendations regarding treatment with the drug are
given to pregnant women.
For ethical reasons, drug studies cannot be conducted
on pregnant women. Animal experiments may be indicative,
but the results cannot be directly transmitted to
humans. Some drug groups have been used over a long
period of time for pregnant women and have proven to be
safe. For several newer drug groups, sufficient evidence
is still lacking. In such cases, the older drug groups
are often used.
In some cases, the mother has a disease that requires
treatment with potentially harmful drugs for the fetus.
An example of this is blood pressure drugs. High blood
pressure can be harmful to mother and fetus and at the
same time some blood pressure drugs can cause birth
defects. Pregnant women who are treated for high blood
pressure are therefore usually treated with drugs other
than those used for women who are not pregnant.
However, switching to a new drug can be risky in
itself, for example in epilepsy and high blood pressure.
It is therefore advantageous if the doctor discusses a
possible pregnancy when a woman of childbearing age
should start a long-term treatment. In this way, the
most appropriate drug can be selected.
In February 2014, a Danish study showed that there
may be a possible link between the use of the painkiller
paracetamol during pregnancy and subsequent
neuropsychiatric injuries in the child. The European
Medicines Agency EMA's safety committee PRAC has
subsequently found that there is no scientific support
for a link between the use of paracetamol during
pregnancy and the impact on the child's neuropsychiatric
The Swedish Medicines Agency's recommendations for
painkillers during pregnancy:
- Every drug treatment should be justified.
- If it is a temporary or short-term pain, try to
relieve it by other methods.
- For pregnant women, medication with paracetamol
is the first choice for pain and fever.
- If you are pregnant and need painkillers for
longer than a few days, this should be discussed
with your doctor.
- Anti-inflammatory drugs (such as ibuprofen,
naproxen and diclofenac) can cause malformations and
miscarriages. These drugs should only be given after
careful medical consideration during the first
two-thirds of pregnancy, and should not be used at
all during the last three months.
There are various ways to make vaccines. Some
vaccines are considered safe to take during pregnancy,
while others should be avoided if you are pregnant. In
particular, vaccines with live, attenuated viruses
should be avoided by pregnant women. This applies, among
other things, to vaccines against red dogs and smallpox.
In general, pregnant women should not be vaccinated
unless there is an acute risk of infection. This can be
a problem in travel or epidemics. During the swine flu
epidemic, the disease was found to cause a serious
course of pregnancy, while the vaccine was considered
harmless. For this reason, the swine flu vaccine is
recommended for pregnant women during the second and
third thirds of pregnancy. This also applies generally
to epidemics with influenza A.
Medicines in connection with childbirth
Both local anesthetic and analgesic medication given
to the mother at birth can have an effect on the child.
Such drugs are therefore used in as small doses as
possible to achieve the intended effect. Especially
opiate (morphine) can cause impaired breathing and
drowsiness in the newborn baby. The same applies to
sedative and anxiety-reducing drugs and anesthetics. In
maternity wards, staff are used to dealing with such
problems and therefore may be more liberal in the use of
Illness or treatment?
The focus is often on harmful effects of substances
in the environment during pregnancy. Of these, smoking
and alcohol are probably the most important substances.
As a rule, drugs do not have adverse effects on the
fetus at normal dosage. When this occurs, the harmful
effects of the treatment should be weighed against the
harmful effects of the disease. Therefore, it is
important to talk to the doctor about both medicines
used during pregnancy and the danger of avoiding taking