The Dangers Of Using Antibiotics During Pregnancy

The use of antibiotics during pregnancy is relatively common. Several women’s health conditions require antibacterial treatments, and there would be no other way to get cured without them.

In the case of a urinary tract infection, for example, or, in its most silent form, asymptomatic bacteriuria, the doctor is forced to prescribe an antibiotic for the pregnant woman.

The point is that using antibiotics during pregnancy can be dangerous if you don’t go the right way. As with all medications, there are adverse reactions to be considered. During pregnancy, these effects can affect both mother and fetus.

While there are extremists who propose not using any medication of any kind during the entire pregnancy, we know that this is often not feasible. So far, the science demonstrated the safety of the use of various drugs during this important period of life of women, including antibiotics.

However, the ban is total for some of them. Likewise, certain antimicrobials cannot be prescribed or used for self-medication during pregnancy, as the result can be disastrous.

How does antibiotic use affect pregnancy?

When an antibiotic is used in pregnancy, the process that the drug follows in the body is very similar to the usual one. Almost all antibiotics end up being excreted in the urine to be eliminated from the body.

In pregnant women, renal flow is increased and so is the volume of urine produced. This results in a faster elimination of the medications and, therefore, a lower concentration of them in the blood.

Anyway, even if it is eliminated more quickly, in the antibiotic what is evaluated is its ability to cross the placenta and reach the fetus. So, once the placenta is crossed, the important thing is whether the substances are teratogenic or not. A teratogenic drug is one that can cause a congenital malformation or miscarriage.

The greatest teratogenic effect of antibiotics occurs in the first three months of pregnancy, that is, until the twelfth week. Later, when the organs are already formed, these drugs no longer cause changes in the organs, but in their function, and they can be just as dangerous.

On the other hand, when evaluating the use of antibiotics during pregnancy, one also considers whether they influence the placenta. Antibiotics that alter placental function restrict fetal growth and cause underweight.

Safe Antibiotics in Pregnancy

The use of antibiotics during pregnancy  is dangerous if the indications and scientific knowledge about them are not respected. Otherwise, they can be safely used when the protocol requires it.

Penicillin and its family of antibiotics have proven to be the safest for the pregnant woman and fetus. All scientific investigations, so far, have not found an association between these drugs and teratogenesis. Even their regular use serves as proof.

The same reasoning applies to the family of cephalosporins, related to penicillin. They are safe to use and useful for urinary infections, for example.

Another antibiotic used in urinary infections in pregnant women, for its safety, is nitrofurantoin. This antimicrobial is particularly useful for pregnant women who are allergic to penicillin.

There is evidence in favor of azithromycin in animal studies. That’s why they fall into category B of pregnancy medications.

Class B drugs are those considered safe for use during pregnancy as they have not presented problems in animal tests, in addition to their frequent use in clinical practice. All this experience makes sure they don’t cause birth defects.

Dangerous Antibiotics During Pregnancy

Among the dangerous and contraindicated antibiotics during pregnancy, we have:

• Aminoglycosides: these have been associated with fetal kidney damage and congenital deafness.
• Tetracyclines: affect the growth of embryonic bones and cartilage, as well as tooth structure.
• Fluoroquinolones:  in clinical experience, they have generated cartilage changes.

The nephrotoxicity of these antibiotics to the mother must also be considered, in addition to fetal risks. Especially when combinations of antibiotics are used, there may be an adverse effect on the pregnant woman’s kidney function.

Just as we talk about class B medications, in this case we have to mention those that are class X. This classification, present in the package inserts, allows us to understand better.

Class X antibiotics are prohibited during pregnancy, as animal and human research, as well as clinical experience, have shown them to be teratogenic. If the drug package or package insert says it is class X, you should not use it during pregnancy.

It is always of utmost importance that you do not self-medicate. The physician is the ideal professional to prescribe and advise on the use of antibiotics during pregnancy. That way you can protect your health and that of your developing baby.