MRI in pregnancy: contraindications, consequences

For one reason or another, we all sometimes have to undergo some diagnostic tests. Women during pregnancy are no exception, because they have to monitor not only their health, but also the development of the unborn child. In addition to a routine ultrasound, a doctor may prescribe an MRI during pregnancy. What is this diagnostic method, and what is it used for?

Is it possible to have an MRI during pregnancy?

MRI (stands for magnetic resonance imaging) is a diagnostic method that uses the properties of magnetic fields. During pregnancy, MRI may be prescribed if necessary to examine diseases of the woman and the fetus.

MRI during pregnancy is used as an independent, isolated study, or as an addition to diagnostics already performed:

• to assess existing pathologies in the fetus;
• for diagnostics of tumor processes;
• to clarify preliminary diagnoses.

Magnetic resonance imaging allows us to detect problems with the spine, joints, and central nervous system.

The Impact of MRI on Pregnancy

The MRI method is sometimes confused with CT – computer tomography, which uses unsafe ionizing rays. The negative impact of radiation on the body has been proven for a long time and does not require additional confirmation. It is especially undesirable to perform CT during pregnancy – it can cause considerable harm to the body of both the mother and the child.

MRI, on the other hand, involves the use of a completely different principle of obtaining information. Inside the MRI machine, a powerful magnetic field with a strength of 0.5-3 T is generated. Such a field cannot initially cause any harm to the human body.

Numerous studies confirm that magnetic resonance imaging is completely safe for both pregnant women and any other patients.

Is MRI harmful during pregnancy? Definitely not. The only condition is that MRI is not recommended in the first trimester. And it is not at all about the fact that it is considered harmful. It is just that the first trimester is the time when the main organs of the future baby are laid. In addition, until the placenta is formed, the fetus still does not have sufficient protection. Therefore, it is better to play it safe and schedule MRI for a later period of pregnancy.

[ 1 ], [ 2 ], [ 3 ]

Advantages and Disadvantages of MRI During Pregnancy

Advantages	Flaws
The procedure is safe, since the method does not involve the use of radiation or X-rays.	The photo may not be available immediately.
It is possible to obtain a three-dimensional image of the area being examined.	Sometimes the image is distorted by breathing movements and heart rhythm.
The resulting image shows natural contrast from blood circulation.	MRI scans are usually relatively expensive.
The outlines of the bone tissue in the image are not distorted.	It is not possible to perform diagnostics on people with metal implants.
Soft tissues have a strictly differentiated display.	A pregnant woman has to stay in a closed space for some time in a motionless state.

[ 4 ], [ 5 ]

Indications for the procedure

MRI during pregnancy cannot be prescribed "just like that": there must be clear indications for this procedure, which are determined by the doctor. Such indications include:

• suspicion of pathologies in the unborn child;
• pathologies of the spine, joints or internal organs in a pregnant woman;
• assessment of indications for abortion;
• clarification of diagnosis if a tumor process is suspected.

In addition, MRI during pregnancy can be used instead of traditional ultrasound in cases where the latter is impossible. For example, ultrasound may not be indicative if the woman is obese or if the baby is in an awkward position in the late stages of pregnancy.

[ 6 ]

Preparation

In most cases, MRI does not require any special preparation. Only in some cases, when examining certain areas, the doctor will recommend a preparatory stage before the procedure.

• Before undergoing an MRI of the internal abdominal organs, it is advisable not to drink or eat food for approximately 5 hours before the procedure.
• Before undergoing an MRI of the pelvis, you must drink enough fluid to fill your bladder.
• Before undergoing an MRI of the spine, you must be prepared to remain motionless for some time - this procedure is not very fast.

Immediately before the procedure, you should remove any metal jewelry, watches, glasses, or piercings.

[ 7 ]

Technique MRI in pregnancy

Before the MRI procedure, the woman is warned about possible contraindications and the intricacies of the diagnostics. After this, the patient, if necessary, changes clothes and, with the help of medical personnel, lies down on a special surface, which is then carefully moved into the MRI machine.

The woman then needs to relax, calm down and wait for the procedure to be over. You must not move while the images are being taken, otherwise you may blur the image.

If you are irritated by extraneous noises, ask the medical staff for special earplugs; during the procedure, the device produces a slight monotonous noise, which can increase the degree of discomfort.

You should be prepared for the fact that the session may last 20-40 minutes.

MRI with contrast during pregnancy

MRI with contrast is most often used to detect tumor and metastatic processes - tomography allows you to assess the size and structure of the pathological focus.

The contrast agent is a gadolinium salt, which is soluble in water and has the lowest toxicity. Other contrast agents can be used for MRI: Endorem, Lumirem, Abdoscan, Gastromark.

The contrast is introduced into the circulatory system and accumulates in the tissues – this makes the area being examined clearer and also allows one to assess the quality of the blood supply to the tissues.

MRI with contrast during pregnancy is allowed to be performed in the second or third trimester, excluding early stages, when the fetus is not yet surrounded by protection - the placental layer. In other cases, the use of contrast agent is not prohibited: if necessary, it is administered even to pediatric patients.

MRI of the brain during pregnancy

MRI of the brain may be prescribed to pregnant women if the following indications are present:

• tumor processes in the brain;
• vascular pathologies in the brain;
• pituitary disorders;
• acute cerebrovascular accident;
• head injuries;
• CNS pathologies;
• severe headaches of unknown origin.

With such indications, MRI diagnostics is more informative. Other procedures cannot always determine the cause of the pathology. MRI during pregnancy not only provides comprehensive information about the state of the brain, but is also a safe method of research.

MRI of the fetus during pregnancy

MRI of the fetus is prescribed during pregnancy if there is a suspicion of gross developmental defects, which may be an indication for artificial termination of pregnancy - abortion.

Many may notice that most patients undergo ultrasound examination to assess the condition of the fetus. However, it is not always possible to perform ultrasound, or it may be uninformative. For example, MRI is preferable if the pregnant woman has a significant fat layer (obesity). Indications for MRI also include oligohydramnios (low water) and an awkward position of the fetus in late pregnancy.

MRI of the sinuses during pregnancy

Diagnosis of the sinuses using MRI is allowed from about the 18th week, but only after consultation with a gynecologist. The doctor can prescribe MRI of the sinuses during pregnancy only if there are strict indications:

• suspected tumors in this area;
• inflammatory process in the sinuses;
• fungal infections of the sinuses;
• cysts and other benign neoplasms;
• bleeding into the nasal cavities, purulent sinusitis.

MRI of the sinuses has no negative effects, even in case of repeated use. This procedure is considered painless and safe.

MRI of the lungs during pregnancy

Magnetic resonance imaging of the respiratory system, namely the lungs and bronchi, is used if a pregnant woman is suspected of having:

• pleurisy;
• vascular changes in the lungs;
• tumor processes;
• pulmonary circulation disorder;
• cystic fibrosis;
• pneumonia;
• atelectasis;
• tuberculosis.

During pregnancy, MRI is much preferable to X-ray examination, which is highly not recommended during this period, as it can cause undeniable harm to the fetus.

MRI in early pregnancy

MRI is not recommended in early pregnancy. However, if there are strict indications, the doctor may prescribe this diagnostic procedure - for example, if there is a suspicion of serious pathologies in the fetus (MRI provides much more information than ultrasound).

If the brain or spinal cord needs to be examined in the first trimester, the doctor will always give preference to MRI. Sometimes MRI can be used instead of ultrasound at the first screening (at 12 weeks). Tomography allows for better tissue visualization, identification of possible fetal defects, and timely medical care.

The magnetic field during MRI does not pose any harm to the human body. The fact that in some cases doctors do not recommend using MRI in the early stages is nothing more than "overcaution". The first trimester is the period when the fetus is actively developing, so medical specialists try to avoid any procedures and interventions at this time.

MRI of the spine in early pregnancy

If spinal diseases worsen with the onset of pregnancy, the doctor may prescribe an MRI procedure to clarify the diagnosis. Is it possible to perform the procedure in the early stages?

If the pathology of the spine is such that you can wait a few weeks until the second trimester, then it is better not to rush with the diagnosis. MRI of the spine in the early stages is carried out only according to strict indications:

• if there is a suspicion of tumor processes in the spine;
• for acute pain of unclear nature.

In principle, the MRI procedure is not dangerous, but it is generally accepted that in the early stages it is performed only if there are emergency indications.

MRI in late pregnancy

Magnetic resonance imaging does not involve the use of ionizing radiation. The main mechanism of action in MRI is the influence of an electromagnetic field. A picture of the required area of the body is obtained as follows: the device generates a magnetic field with a power of 0.5-2 T, and waves are directed to the area being examined, transmitting a rotational impulse to the protons. After the waves cease to act, the particles "calm down", simultaneously generating a certain dose of energy, registered by a special hardware sensor. The reaction of atoms to the influence of electromagnetic waves is described by the term "resonance", which determines the name of the MRI procedure.

If you carefully study the mechanism of action of this type of diagnostics, you can see that the procedure does not have any destructive consequences for the body. At least, the magnetic field used in MRI machines can be used in medicine without any risk, including in the late stages of pregnancy.

Contraindications to the procedure

It is not advisable to perform MRI during pregnancy in the first trimester - during the period of formation of the main organs of the future baby. Although the presence and extent of harm from MRI for the child even in this period has not been proven.

Other contraindications for MRI during pregnancy include:

• the presence of metallic interference in the body that can affect the function of the magnetic field (pacemakers, metal implants, frames and spokes);
• the woman's body weight is more than 200 kg.

Since MRI involves placing the patient in a confined space, people suffering from claustrophobia or certain mental disorders are usually not allowed to undergo the procedure.

[ 8 ], [ 9 ]

Complications after the procedure

Often women who are concerned about the normal course of pregnancy and the condition of the future child are wary of such a diagnostic method as MRI. However, over all the years of practice, no negative consequences have been noted after this procedure.

If a pregnant woman undergoes an MRI scan in the absence of contraindications, she will not harm her baby’s health in any way.

However, despite everything, MRI during pregnancy should be performed only if there are strict medical indications, and not for "interest". MRI is a very serious method and is prescribed only by a doctor for specific diagnostic purposes.

[ 10 ], [ 11 ]