Decidual reaction

Decidual Reaction
Synonyms
Pronounce	N/A
Specialty	N/A
Symptoms	N/A
Complications	N/A
Onset	N/A
Duration	N/A
Types	N/A
Causes	N/A
Risks	N/A
Diagnosis	N/A
Differential diagnosis	N/A
Prevention	N/A
Treatment	N/A
Medication	N/A
Prognosis	N/A
Frequency	N/A
Deaths	N/A

The decidual reaction is a critical process in early pregnancy, involving the transformation of the endometrial stromal cells into specialized decidual cells. This transformation is essential for the successful implantation of the blastocyst and the establishment of the placenta.

Physiology

The decidual reaction occurs in the endometrium, the inner lining of the uterus. It is primarily driven by hormonal changes, particularly the increase in progesterone levels following ovulation. Progesterone, secreted by the corpus luteum, prepares the endometrium for potential implantation by inducing the decidualization of stromal cells.

Decidualization

Decidualization is the process by which endometrial stromal cells undergo morphological and functional changes to become decidual cells. These changes include:

• Enlargement of the cells
• Increased cytoplasmic volume
• Accumulation of glycogen and lipids
• Secretion of cytokines and growth factors

These changes create a supportive environment for the developing embryo and facilitate the invasion of the trophoblast cells of the blastocyst.

Role in Implantation

The decidual reaction is crucial for the implantation of the blastocyst. The decidualized endometrium provides a receptive environment for the blastocyst to attach and invade. The decidual cells secrete various factors that modulate the immune response, preventing the maternal immune system from rejecting the semi-allogeneic embryo.

Immune Modulation

Decidual cells produce prostaglandins, interleukins, and other immunomodulatory molecules that:

• Promote tolerance of the embryo
• Inhibit the activation of natural killer cells
• Regulate the activity of macrophages and T cells

Clinical Significance

The decidual reaction is a marker of early pregnancy and can be observed via ultrasound as a thickened, echogenic endometrial lining. Abnormalities in the decidual reaction can lead to pregnancy complications such as:

• Ectopic pregnancy
• Miscarriage
• Placental abruption

Pathological Conditions

In some cases, the decidual reaction can occur outside the uterine cavity, such as in ectopic pregnancies, where the decidualization occurs in the fallopian tubes. This can lead to complications and requires medical intervention.

Conclusion

The decidual reaction is a vital process in early pregnancy, ensuring the proper implantation and development of the embryo. Understanding this process is crucial for diagnosing and managing early pregnancy complications.