[5] The temporal and spatial expression of GD in the female reproductive tract combined with its biological activities suggest that this glycoprotein probably plays an essential physiological role in the regulation of fertilization, implantation and maintenance of pregnancy.

The four cysteinyl residues (positions 66, 106, 119, and 160) responsible for intramolecular disulfide bridges in lactoglobulins are all conserved in GD.

[9][10] GD is the most important protein secreted in the endometrium during the mid-luteal phase of the menstrual cycle and during the first semester of pregnancy.

These glycoproteins have distinct and essential roles in regulating a uterine environment suitable for pregnancy and in the timing and occurrence of the appropriate sequence of events in the fertilization process.

In the female genital tract is mainly expressed in EECs (cultured endometrial epithelial cells) and secreted into the amniotic fluid, endometrium/decidua and maternal serum.

Glycodelin-A has contraceptive and immunosuppressive functions, due to the fact that suppresses Natural Killer cells, achieving the prevention of the maternal rejection of the fetus at the fetromaternal interface.

A number of alternatively spliced transcript variants have been observed at this locus, but the full-length nature of only two, each encoding the same protein, has been determined.

Glycodelin-F reduces the blinding of spermatozoa to the zona pellucida which is mainly expressed in the ovary, and synthesised in the granulosa cells, has a function in principle similar to that of Glycodelin-A.

Biomarker of premature rupture of membranes Premature rupture of membranes is a common pregnancy complication, taking into account that the current method does not satisfy the medical community, some researches have determined a new method: the analysis of placental protein in the maternal plasma and vaginal fluid.

Some studies have shown that the serum concentration of Placental Protein 14 was highly increased after the embryo transfer cycle, and they conclude that PP-14 might be an excellent marker to predict the endometrial receptivity.