Pelvic girdle pain (abbreviated PGP) can be described as a pregnancy discomfort for some women and a severe disability for others. PGP can cause pain, instability and limitation of mobility and functioning in any of the three pelvic joints. PGP has a long history of recognition, mentioned by Hippocrates and later described in medical literature by Snelling. The affection appears to consist of relaxation of the pelvic articulations, becoming apparent suddenly after parturition or gradually during pregnancy and permitting a degree of mobility of the pelvic bones which effectively hinders locomotion and gives rise to the most peculiar and alarming sensations. Classification
Prior to the 20th century, specialists of pregnancy-related PGP used varying terminologies. It is now referred to as Pregnancy Related Pelvic Girdle Pain that may incorporate the following conditions:

Diastasis of the symphysis pubis (DSP)
Symphysis pubis dysfunction (SPD)
Pelvic Joint Syndrome
Physiological Pelvic Girdle Relaxation
Symptom Giving Pelvic Girdle Relaxation
Posterior Pelvic Pain
Pelvic Arthropathy
Inferior Pubic Shear/ Superior Pubic Shear /Symphyseal Shear
Symphysiolysis
Osteitis pubis (usually postpartum)
Sacroiliitis
One-sided Sacroiliac Syndrome /Double Sided Sacroiliac Syndrome
Hypermobility"The classification between hormonal and mechanical pelvic girdle instability is no longer used. For treatment and/or prognosis it makes no difference whether the complaints started during pregnancy or after childbirth." Mens (2005)

Signs and symptoms
A combination of postural changes, baby, unstable pelvic joints under the influence of pregnancy hormones, and changes in the centre of gravity can all add to the varying degrees of pain or discomfort.
Pain may also be present when lifting, carrying, pushing or pulling. The symptoms (and their severity) experienced by women with PGP vary, but include:

Present swelling and/or inflammation over joint. Difficulty lifting leg. Pain pulling legs apart. Inability to stand on one leg. Inability to transfer weight through pelvis and legs. Pain in hips and/or restriction of hip movement. Transferred nerve pain down leg. Can be associated with bladder and/or bowel dysfunction. A feeling of the symphysis pubis giving way. Stooped back when standing. Malalignment of pelvic and/or back joints. Struggle to sit or stand. Pain may also radiate down the inner thighs. Waddling or shuffling gait. Audible clicking sound coming from the pelvis. Severity
The severity and instability of the pelvis can be measured on a three level scale. Pelvic type 1:The pelvic ligaments support the pelvis sufficiently. Even when the
muscles are used incorrectly, no complaints will occur when performing everyday activities. This is the most common situation in persons who have never been pregnant, who have never been in an accident, and who are not hypermobile. Pelvic type 2:The ligaments alone do not support the joint sufficiently. A
coordinated use of muscles around the joint will compensate for ligament weakness. In case the muscles around the joint do not function, the patient will experience pain and weakness when performing everyday activities. This type often occurs after giving birth to a child weighing 3000 grams or more, in cases of hypermobility, and sometimes after an accident involving the pelvis.