In older children and adults, the tumor may be mistaken for a pilonidal sinus, or it may be found during a rectal exam or other evaluation. Diagnosis
During prenatal ultrasound, an SCT having an external component may appear as a fluid-filled cyst or a solid mass sticking out from the fetus body. Fetal SCTs that are entirely internal may be undetected if they are small;  detection (or at least suspicion) is possible when the fetal bladder is seen in an abnormal position, due to the SCT pushing other organs out of place. At birth, the usual presentation is a visible lump or mass under the skin at the top of the buttocks crease. If not visible, it can sometimes be felt; gently prodded, it feels somewhat like a hardboiled egg. A small SCT, if it is entirely inside the body, may not present for years, until it grows large enough to cause pain, constipation and other symptoms of a large mass inside the pelvis, or until it begins to extend out of the pelvis. Even a relatively large SCT may be missed, if it is internal, because the bony pelvis conceals and protects it. Mediastinal tumors, including teratomas, are similarly concealed and protected by the rib cage. Some SCTs are discovered when a child begins to talk at about age 2 years and complains of their bottom hurting or feeling "poopy" when they ride in a car seat.
Only when the site of detachment occurs on the side facing the cervical opening can the total amount of haemorrhaging be measured by vaginal bleeding. Using vaginal bleeding as a measurement of the severity of the placental abruption is therefore ineffective. The scale of haemorrhaging depends on the degree to which the placenta has separated from the uterine wall. In the case of partial placental separation, haemorrhaging can be minor. However, in the case of total placental separation haemorrhaging will be major and emergency delivery will typically be the course of action. Placental abruption causes blood loss from the mother and loss of oxygen and nutrients to the placenta occasionally leading to preterm labour. Other causes of placental abruption can be abdominal trauma or sudden decompression of amniotic fluid, however it is not uncommon for the cause of placental abruption to be unknown. Vasa praevia
Vasa praevia is the presence of unprotected foetal blood vessels running along the placenta and over the internal cervical opening. Vasa praevia is a very rare, presenting only 4:10,000 cases from the largest study of the condition. Risks of antepartum bleeding due to vasa praevia greatly increase during the third trimester of pregnancy during cervical dilation or placenta praevia. Vessel rupture is very likely in the event of a membranous rupture as foetal blood vessels arent protected by the umbilical cord of the placenta. In the event of foetal vessel rupture, antepartum haemorrhaging occurs however blood is lost from the foetal blood supply.