Examinations
Examinations
Free estriol is a steroid hormone that is crucial for a healthy pregnancy. It is synthesized by the placenta. Compared to estradiol and estrone, estriol is less active and plays a minor role in non-pregnant women. However, during pregnancy, estriol becomes the dominant estrogen, ensuring the normal progression of pregnancy.
- Estriol stimulates the synthesis of vasodilatory prostaglandins in endometrial cells, enhancing uteroplacental blood circulation.
- It also promotes mammary gland growth in preparation for lactation.
Estriol Synthesis During Pregnancy
- The placenta lacks all the enzymes necessary to synthesize estrogens from cholesterol.
- Therefore, it relies on precursor substances from both the fetus and the mother.
- One key precursor is DHEA-S, which is synthesized in the maternal adrenal glands.
- When DHEA is metabolized in the placenta, it is converted into estradiol and estrone.
- A small portion of these hormones is then further converted into estriol.
- The analysis is performed on a blood sample drawn from a vein.
- 30 minutes before the test, avoid physical and emotional stress.
- Pregnancy monitoring, especially in cases of fetal developmental risks.
- Symptoms of late toxicosis (gestational complications).
- Signs of hyperestrogenism.
- Assessment of the risk of complications in the third trimester.
Causes of Increased Estriol Levels
- Multiple pregnancy (twins, triplets, etc.)
- Hormone-active ovarian or adrenal tumors
- Liver cirrhosis
Causes of Decreased Estriol Levels
Fetal Conditions:
- Fetal diseases
- Anencephaly
- Intrauterine fetal death
- Miscarriage
- Fetal growth restriction
- Down syndrome, Edwards syndrome
- X-linked ichthyosis, Smith-Lemli-Opitz syndrome
- Rh or ABO incompatibility
Maternal Conditions:
- Choriocarcinoma
- Preeclampsia
- Menopause
Medications That Reduce Estriol Levels:
- Glucocorticoids
- Estrogens
- Penicillin
- Meprobamate
- Phenazopyridine