The infundibulopelvic ligament, also known as the IP ligament, or simply IP, is not actually a true ligament. It is a folded band of peritoneal tissue — the membrane lining the abdominal space — and it is connected to the ovaries near the apex on each side. In addition to carrying out the function of binding the ovaries securely to the pelvic wall, the ligament also holds vital arteries, veins, nerves, and lymph glands for nourishing the ovaries.
The membranous tissue forming the infundibulopelvic ligament is characterized as nonmuscular epithelial tissue that is smooth and bathed in body fluid. It is different than connective tissue in that it does not contain the fiber cells and collagen that characterize muscular tissue. Although this ligament consists of one continuous structure of folded peritoneal tissue, it is often named according to the locations where it attaches to other structures. For instance, at its attachment to the pelvic wall, it is often called the “peritoneum” or “peritoneal ligament.”
At its other end, where the infundibulopelvic ligament attaches to the ovary, it has also been termed the “broad ligament,” which may be partly due to the fact that the broad ligament itself is a very wide band of folded peritoneal lining that connects the uterus to the sides of the pelvis and spreads out to the ovaries — an area known as the mesosalpinx. In fact, some medical specialists believe that the infundibulopelvic ligament is not actually a separate structure from the broad ligament, but is merely a hollowed-out extension of the broad ligament's margins.
The infundibulopelvic ligament is also called the suspensory ligament of the ovary. This ligament is a separate structure from the utero-ovarian ligament, a ligament consisting of fibrous tissue that extends from the inner lower part of the ovary to the uterus. Moreover, while the utero-ovarian ligament is essentially a muscular ligament that anchors the ovaries to the uterus, the IP ligament anchors the ovaries to the pelvis and also contains essential conduits for maintaining and nourishing the ovaries.
Because the infundibulopelvic ligament is closely bound to the ovary, and it is also in close proximity to the uterus, it is part of two commonly treated areas in gynecology — the branch of medicine that treats conditions and diseases of the female reproductive system. While the ovaries in younger women commonly develop benign cysts that tend to go away by themselves, ovarian growths that are not benign, such as a tumor or cancer, may require treatment by surgery. Surgery involving the IP ligament generally tries to preserve much of the ligament, along with its mesh of blood and lymphatic vessels.