Anesthesia during pregnancy


It happens that general anesthesia cannot be avoided in women who are pregnant. The planning and implementation of these non-gynecological interventions is carried out by the treating anesthetist. In total, 0.5% - 1.6% of all pregnant women undergo such an operation every year.

General anesthesia and the associated surgical intervention during pregnancy always pose a certain risk for both mother and child, which is why the decision for such an intervention should never be made lightly.
General anesthesia ensures that during a surgical procedure no pain can be perceived and that the patient not conscious is. Also be vegetative reflexes switched off and the Musculature of the body relaxed.

All drugs that are used for general anesthesia are Placenta common and get to the fetus. Whether the medication can harm the child's development is currently being investigated and has not yet been clarified with certainty. A compound of was obtained in the animal model Childhood anesthesia to a later occurring Learning disability detected. However, retrospective studies have so far only partially confirmed this relationship.

Special features of anesthesia during pregnancy

General anesthesia for a pregnant woman is always a challenge for the treating team, since instead of only having one patient as usual, responsibility for two patients must now be assumed. At the same time, some biological changes take place during pregnancy that must be taken into account when performing anesthesia.

The change in the respiratory organs is a particularly important part of monitoring the anesthesia. It is important to provide the mother, and thus also the child, with sufficient oxygen, otherwise damage to the child cannot be ruled out.
Paradoxically, an oversupply of oxygen to the mother is counterproductive for the supply of the fetus, since if there is too much oxygen in the mother's blood, less oxygen reaches the child via the placenta.
The changes in the respiratory organs mean that the anesthetic gases act faster, but can also escape faster from the body when the agent is discontinued. At the same time, there is increased blood flow to the mucous membranes, which is difficult for securing the airways through intubation. Bleeding occurs more frequently, or the airways must be secured in a different way in these cases.

Pregnancy also changes the cardiovascular and vascular system. The blood volume and the pulse rate continue to increase in the course of pregnancy. At the same time, the mother's blood pressure also rises.

Can I have a local anesthetic during pregnancy?

In principle, local anesthesia can be carried out safely during pregnancy. It should only be clarified in advance that a pregnancy exists so that the local anesthetic and, if necessary, the dose of the local anesthetic can be adjusted.

If possible, surgery during pregnancy should preferably be performed under local anesthesia rather than general anesthesia. However, only interventions that require immediate action should be carried out, i. that is, if it is possible to postpone the procedure after the birth, this would be the best option for both mother and child.

Read more on the topic: partial anesthesia

What are the risks for the baby with local anesthesia?

With the correct choice of local anesthetic and the correct administration and dosage, there are no risks to the unborn child.
Basically, preparations should be preferred that have a high plasma protein binding in order to keep a systemic effect low.

However, additives such as adrenaline and noradrenaline in the narcotic mixtures, which can lead to vasoconstriction, i.e. narrowing of the vessels, can be dangerous for the baby. If there is also a vasoconstriction in the supplying vessels of the placenta, it can lead to severe placental insufficiency with a life-threatening inadequate supply of the fetus. In addition to placental insufficiency, these additives can also lead to palpitations and fluctuations in blood pressure in the baby.

If adrenaline or noradrenaline is used, a high dilution (e.g. 1: 200,000) must therefore be ensured.

Drugs for anesthesia during pregnancy

Anesthesia for a pregnant woman is a specialty of anesthesia when it comes to the choice of medication. The anesthetic gas should be dosed lower in pregnant women, as these act faster by changing the respiratory organs.
Laughing gas should be avoided for use as an inhaled anesthetic gas in the anesthesia of pregnant women, as there is a relative risk of abortion.

The risks in the use of drugs injected intravascularly into the vasculature lie in the need for precise dosing of these substances.
Overdosing can easily damage the fetus, whereas underdosing should be avoided in the interests of the mother. At the same time, it should be noted that the use of some anesthetics can reduce or increase the muscle tension in the uterus and thus contractions may occur during the operation, which can lead to the abortion of the fetus.

Propofol during pregnancy

Propofol has become the drug of choice for most anesthetics.

Insufficient data is available on the possible consequences of anesthesia with propofol for the unborn child during pregnancy.

For this reason, its use is only recommended in absolutely necessary cases and the dose should be kept as low as possible. Like many other drugs, propofol can also get into the child's bloodstream via the umbilical cord and placenta and thus also anesthetize the child in a certain way and impair its circulatory function.
The reason for this is the high fat solubility of propofol.

On the one hand, this is necessary so that propofol can work well in the brain and cause the loss of consciousness there. Unfortunately, it is precisely this fat solubility that also causes the child's anesthesia, since fat-soluble drugs can get into the child's circulation particularly well through the placenta.

Please also read the article on the topic Propofol.

What complications can arise?

During the operation, the mother's blood pressure must be monitored in particular, as a drop in blood pressure can cause considerable harm to the fetus.

In general, the same side effects and complications apply to the anesthesia of pregnant women as to healthy people. Anesthesia is always a medical procedure and should not be performed without a serious reason, especially during pregnancy.
In the special case of anesthesia in pregnant women, there are other things to consider:

Aortocaval Compression Syndrome is a well-known complication of late pregnancy. It is caused in about 16% -20% of all pregnant women by taking the supine position.
Here, the uterus presses on two important large vessels in the body (aorta and vena cava) and can thus trigger severe side effects with symptoms of shock.

Some anesthesiological procedures, such as general anesthesia, promote the occurrence of this syndrome through normal positioning. If possible, the woman should therefore be positioned in such a way that the probability of spontaneous occurrence of the aortocaval syndrome remains as low as possible.

The changes in the abdomen of a pregnant woman also lead to more frequent aspiration of stomach contents during anesthesia. For this reason, pressure on the abdomen during the operation should be avoided if possible and the risk of aspiration through intubation should be kept to a minimum. Performing the procedure while in an elevated position also reduces the risk.

In pregnant women, it is particularly important to keep an eye on blood pressure during the operation, as a sudden drop in blood pressure can damage the fetus.

The risk of spontaneous abortion during anesthesia is another complication during anesthesia. Through the use of anesthetics, which are common to the placenta and thus also reach the fetus, as well as the stress caused by the procedure, an abortion of the child cannot be ruled out during the procedure.

Read more on the topic: Side effects of anesthesia

Risks of anesthesia during pregnancy

In general, the reasons for an operation and the associated anesthesia during pregnancy must be weighed very carefully and anesthesia should only be carried out in the case of interventions that cannot be postponed.
The pregnant woman is in a time full of physical changes, which must also be observed during the anesthesia.

Read more about the topics:

  • Skin changes during pregnancy
  • Changes in the nipples during pregnancy

Every anesthetic procedure has its own risks.
The special features of epidural anesthesia, an anesthetic that is injected into the spinal canal, are the side effects that are common for this type of anesthesia, such as headaches and a drop in blood pressure. In the worst case, the child will be insufficiently supplied.
Nevertheless, peridual anesthesia is considered very safe for the unborn child.

General anesthesia is a bit more risky during pregnancy. In contrast to the anesthesia in the spinal canal, the mother-to-be is completely put into a coma and is unconscious for the duration of the operation, while this remains in a peridual anesthesia.
In the case of general anesthesia, it is important to note that the artificial coma is induced by medication in the mother's bloodstream or by inhaled anesthetic gases. These then always reach certain proportions through the umbilical cord to the child, who is also anesthetized to a certain extent. Studies have shown that there is an increased risk of premature births or miscarriages with general anesthesia during pregnancy. It has also been shown that with general anesthesia during childbirth, a higher rate of newborns suffer from breathing difficulties.

Read more on the topic: Risks of anesthesia

Risks to the baby from anesthesia

A pregnant woman is usually only operated on under general anesthesia if it is an unavoidable procedure that is intended to ensure the survival of the pregnant woman. Other procedures should either be postponed until after the birth or performed under local anesthesia.

Anesthesia in the first and second trimester of pregnancy can be dangerous for the embryo; in the last trimester there are fewer risks for the unborn child.

Scientifically, no increased incidence of malformations in the embryos when the mother is anesthetized has been proven. However, it has been shown to be at greater risk for it to occur

  • a miscarriage,
  • infant death up to 168 hours after birth and
  • the child is underdeveloped (low body weight and height).

Statistics on anesthesia during pregnancy

Every year approx. 0.5% - 1.6% of all pregnant women undergo surgery including general anesthesia.

About 0.5% -1.6% of all pregnant women have to undergo a non-gynecological operation during their pregnancy. Of these interventions, around 40% are performed in the first trimester, 35% in the second and 25% in the third trimester. The risk of the mother's death during anesthesia was given as 0.006% in a study with over 12,000 patients.

The risk of spontaneous abortion of the fetus has also been investigated in some studies. These studies came to very different results, although they all had in common that the risk of having a miscarriage is logically increased by surgery.
Depending on the study, the risk was 0.6% to 6.5% higher than in women who did not have to undergo surgery with anesthesia. According to study results, the risk of this complication is significantly greater if the procedure was performed during the first trimester.
Studies have not yet been able to definitively clarify the connection between the substances used in anesthesia and related neuronal damage.

Overall, however, studies have shown that the likelihood of miscarriages, premature births and infants who are underweight at birth are linked to an operation performed under general anesthesia.

Alternatives to anesthesia during pregnancy

If possible, surgery and the necessary anesthesia are avoided during pregnancy. Incalculable risks are too great for elective surgery.
If an intervention cannot be avoided during pregnancy, regional anesthesia is the first choice. Regional anesthesia also involves risks, but is much better tolerated by pregnant women and children. Studies show that the risk of dying from anesthesia is about half as high when using regional anesthesia than when using general anesthesia. Nonetheless, many pregnant women are operated on with general anesthesia every year, as there is no alternative for many operations.

Anesthesia during pregnancy at the dentist

Even if anesthesia should always be carefully weighed up during pregnancy, dental interventions are usually not a problem. In any case, the dentist must be informed about the pregnancy in order to be able to observe the specifics of anesthesia during pregnancy.

In contrast to major operations under general anesthesia, which should not be used in the first few months of pregnancy, procedures at the dentist can usually still be carried out, as local anesthesia of the oral cavity is sufficient and no risky general anesthesia is necessary.

Actually, no medication is intended in the bloodstream for local anesthesia, but there is still a risk of transfer, which affects the selection of the medication for local anesthesia, as one must also be prepared for this incident.
The usual drugs (= local anesthetics) are very fat-soluble and can easily pass through the umbilical cord into the child's circulation.

Therefore, for pregnant women, narcotics should be selected that are not so easily soluble in fat and that cannot get into the child's circulation in the event of a narcotic leak into the mother's bloodstream.
Usually, drugs are added to the local anesthetic agents to narrow the blood vessels. This addition prevents the drug from spreading excessively and causing major bleeding.
Here, adrenaline derivatives should be used during pregnancy, as some other substances can promote labor.

If you take all these peculiarities into account, there is usually nothing standing in the way of dental procedures under local anesthesia.

More on this topic at: Local anesthetics in pregnancy

If fear of operations plays another major role, tranquilizers can be used. Benzodiazepines such as diazepam have proven particularly suitable. These can be used briefly during pregnancy with a clear conscience to dampen the expectant mother's stress reactions, because these can also be felt by the unborn child.

Read more on the topic: Anesthesia at the dentist