The cardinal function of decidua is
A. Immunity
B. Production of hormones
C. All of these .
D. Maintenance of pregnancy
Correct Answer: D. Maintenance of pregnancy
Explanation
The cardinal (primary/most important) function of the decidua during pregnancy is to regulate trophoblast invasion and prevent excessive invasion of the maternal endometrium by the fetal trophoblast.
Key roles that make this the “cardinal” function include:
• The decidua acts as a physical and immunological barrier that limits how deeply the extravillous trophoblast can invade the maternal spiral arteries and myometrium.
• It secretes various cytokines, growth factors, and matrix metalloproteinase inhibitors (e.g., TGF-β, IGFBP-1, TIMPs) that control trophoblast migration and invasiveness.
• Decidual natural killer (dNK) cells and macrophages play a major role in immune tolerance and remodeling of spiral arteries while keeping invasion in check.
If the decidua fails in this regulatory role:
• Too little invasion → preeclampsia, fetal growth restriction
• Too much invasion → placenta accreta spectrum disorders
Other important functions (nutrient/waste exchange, hormone production, immune tolerance) are significant, but the cardinal, defining function that makes the decidua unique (compared to non-pregnant endometrium) is its role as the gatekeeper of controlled trophoblast invasion.
So, in most obstetrics and reproductive biology textbooks, the cardinal function of the decidua is: regulation (limitation) of trophoblast invasion.
Other Options Details
The question appears to be a multiple-choice question where the options are:
A. Immunity
B. Production of hormones
C. All of these
D. Maintenance of pregnancy
And you have selected/asked about C. All of these, while also requesting to “Describe the All options”.
This type of question is most commonly asked in biology/reproductive physiology about the functions of the placenta during pregnancy.
Here is a clear description of all the options in that context:
A. Immunity
Correct. The placenta plays a role in immunity by:
• Acting as a barrier against many pathogens
• Transferring maternal antibodies (especially IgG) to the fetus, providing passive immunity
• Producing immune-modulating factors that prevent the mother’s immune system from rejecting the fetus (which is genetically half-foreign)
B. Production of hormones
Correct. The placenta is a major endocrine organ during pregnancy and produces several critical hormones, including:
• Human Chorionic Gonadotropin (hCG)
• Progesterone (takes over from the corpus luteum)
• Estrogen (human placental lactogen, estriol, etc.)
• Placental growth hormone
• Relaxin, etc.
These hormones are essential for maintaining pregnancy and preparing the mother’s body for childbirth and lactation.
• D. Maintenance of pregnancy
Correct. The placenta is absolutely essential for maintaining pregnancy after the first trimester by:
• Producing progesterone to prevent uterine contractions and shedding of the endometrium
–
• Faciliting nutrient, oxygen, and waste exchange between mother and fetus
• Removing waste products from the fetal blood
• Supporting continued fetal growth and development
C. All of these
This is the correct answer.
The placenta performs all the functions listed:
• Provides immunity (passive immunity + immune tolerance)
–
• Produces vital hormones
• Is essential for the maintenance of pregnancy
So, the placenta does A, B, and D → therefore the answer is C. All of these.