Rare Diseases in Pregnancy

Today, we'll look at several rare diseases in pregnancy, including HELLP syndrome. This is characterized by bleeding and liver problems.
Rare Diseases in Pregnancy

Last update: 21 May, 2021

It’s common for women to fear rare diseases in pregnancy, both because of the maternal concern that this produces and because of the possible consequences for the baby’s health. These include cancer, hyperthyroidism, acute fatty liver disease, and HELLP syndrome. We’ll discuss some of the specifics of each below.

Many of them can be prevented or cured early through proper prenatal care. Hence the importance of seeing an obstetrician as soon as you become aware that you’re pregnant. Or, even before thanks to family planning consultations.

What characterizes these diseases?

Some of these conditions can be confused with pre-existing diseases, such as cancer or hyperthyroidism. This means that they may have been diagnosed by chance during pregnancy due to symptoms or routine check-ups.

However, the rare diseases in pregnancy that we’ll mention below are characterized by being related to gestation. So, their appearance has a close relationship to the changes in the mother’s body during this stage.

Rare diseases in pregnancy

All the pathologies we’ll describe below are part of the Orphanet classification of rare disorders connected with pregnancy, birth, and puerperium. This is an initiative that aims to raise awareness and promote research into rare diseases.

1. Cancer

A woman in her first trimester undergoing an ultrasound.
This type of disease requires several complementary studies to be diagnosed.

According to a publication by the US National Library of Medicine, the occurrence of cancer during pregnancy is rare but possible. Some of these malignant tumors can affect only the mother, so that detection during pregnancy is a coincidence. This is the case of breast or cervical cancer.

On the other hand, there’s gestational trophoblastic disease, which appears as a result of the interaction between an egg and a sperm. When these meet, it’s possible for the cells to proliferate into a type of cancer known as choriocarcinoma. This tumor is formed by cells that, under normal conditions, give rise to the placenta.

Diagnostic methods are available to detect the disease in its early stages and the treatment currently available is effective. However, undetected cases can result in the death of the mother, especially when there’s metastasis to distant organs such as the lungs.

2. Acute fatty liver disease: one of the rare diseases in pregnancy

The liver is an organ in charge of multiple metabolic processes in the body, something vital for the handling of nutrients and other substances. This rare disease in pregnancy is characterized by the abrupt failure of the organ which, in turn, can affect the renal, neurological, and hematological systems.

There are several risk factors, although the cause of this condition remains unknown so far. Some of them are the use of medications (such as aspirin) and obesity.

From a clinical point of view, the most frequent symptoms are nausea, pain, yellowing of the skin (jaundice), and accumulation of fluid in the abdomen (ascites).

3. Gestational hyperthyroidism

The thyroid plays a regulatory role in the metabolism of the whole body and it’s not uncommon to find cases of hypo- or hyperthyroidism in the general population, although it’s rare in pregnant women. Gestational hyperthyroidism usually begins in the first trimester and sometimes the symptoms go unnoticed.

The consequences for the mother include an increased risk of developing thrombosis (for which there are some warning signs worth knowing) and preeclampsia. Without treatment, miscarriage may even occur. As for the baby-to-be, developmental problems, such as intrauterine growth retardation, are common.

A stethescope and a plastic model of the thyroid gland.
Thyroid problems can affect almost the entire body.

Find out more: How Diet Affects Fertility: What You Should Know

4. HELLP syndrome

HELLP syndrome is one of the most well-known rare diseases in pregnancy, at least in the medical field. It’s considered an emergency due to its ability to put the life of the mother and baby at risk in a short period of time.

It usually has to do with preeclampsia (a type of hypertension in pregnancy) and involves liver damage and alterations in red blood cells and platelets, leading to anemia and bleeding disorders.

From a clinical point of view, jaundice, ascites, and symptoms related to the exaggerated increase in blood pressure may also appear in this condition. These include blurred vision, headache, or swelling in the legs.

Prenatal screening: the best way to prevent rare diseases in pregnancy

Although today it’s common to attend a prenatal check-up as soon as you know you’re pregnant (even earlier, in the best of cases), some mothers may be reluctant to go. Fear of the unknown and lack of interest in having a “strict” pregnancy are some of these reasons.

However, once you start going for prenatal visits, your obstetrician will become a great companion along the way. Routine screenings and evaluations are necessary in order to prevent future health problems, which can save more than one life.

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  • Carrasco C, et al. Hipertiroidismo gestacional: análisis a propósito de un caso asociado a mola. Rev Med Chile 2001;129(3).