Sonography can demonstrate that the pregnancy is outside an empty uterus, there is reduced to no amniotic fluid between the placenta and the fetus,  no uterine wall surrounding the fetus, fetal parts are close to the abdominal wall, the fetus has an abnormal lie, the placenta looks abnormal and there is free fluid in the abdomen. MRI has also been used with success to diagnose abdominal pregnancy and plan for surgery. Elevated alpha-fetoprotein levels are another clue of the presence of an abdominal pregnancy. Ultrasound
Most cases can be diagnosed by ultrasound. The diagnosis however may be missed with ultrasound depending on the operators skill. Criteria
To diagnose the rare primary abdominal pregnancy, Studdifords criteria need to be fulfilled: tubes and ovaries should be normal, there is no abnormal connection (fistula) between the uterus and the abdominal cavity, and the pregnancy is related solely to the peritoneal surface without signs that there was a tubal pregnancy first. Studdifords criteria were refined in 1968 by Friedrich and Rankin to include microscopic findings. Differential diagnosis
Depending on gestational age the differential diagnoses for abdominal pregnancy include miscarriage, intrauterine fetal death, placental abruption, an acute abdomen with an intrauterine pregnancy and a fibroid uterus with an intrauterine pregnancy . Treatment
Ideally the management of abdominal pregnancy should be done by a team that has medical personnel from multiple specialties. Potential treatments consist of surgery with termination of the pregnancy (removal of the fetus) via laparoscopy or laparotomy, use of methotrexate, embolization, and combinations of these.
Sapuri and Klufio indicate that conservative treatment is also possible if the following criteria are met: 1. there are no major congenital malformations; 2. the fetus is alive; 3. there is continuous hospitalization in a well-equipped and well-staffed maternity unit which has immediate blood transfusion facilities; 4. there is careful monitoring of maternal and fetal well-being; and 5. placental implantation is in the lower abdomen away from the liver and spleen. The choice is largely dictated by the clinical situation. Generally, treatment is indicated when the diagnosis is made; however, the situation of the advanced abdominal pregnancy is more complicated. Advanced abdominal pregnancy
Advanced abdominal pregnancy refers to situations where the pregnancy continues past 20 weeks of gestation (versus early abdominal pregnancy < 20 weeks). In those situations, live births have been reported in the lay press where the babies are not uncommonly referred to as Miracle babies. A patient may carry a dead fetus but will not go into labor. Over time, the fetus calcifies and becomes a lithopedion.It is generally recommended to perform a laparotomy when the diagnosis of an abdominal pregnancy is made. However, if the baby is alive and medical support systems are in place, careful watching could be considered to bring the baby to viability. Women with an abdominal pregnancy will not go into labor. Delivery in a case of an advanced abdominal pregnancy will have to be via laparotomy.