The incidence of acute abdomen during pregnancy (excluding obstetric emergencies) is 1/500-700 and can be caused by gastrointestinal, gynecological, urological, vascular, and traumatic lesions, of which approximately 0.2-2% require surgical intervention. Due to the anatomical and physiological changes caused by pregnancy, as well as the limited experience of most physicians in this area, it is often difficult to establish a diagnosis, delay treatment, and increase the incidence of complications for both the pregnant woman and the fetus. This article focuses on the diagnosis and management of surgical emergencies during pregnancy, the most common of which is acute appendicitis during pregnancy. I. Clinical presentation Acute appendicitis is the most common surgical emergency abdomen in pregnancy, with an incidence of about 0.5-2/1000 pregnancies, accounting for 25% of all non-obstetric emergency abdominal conditions. It usually occurs in the 3rd-6th months of pregnancy and its overall incidence does not change among pregnant women. Acute appendicitis in pregnant women is more difficult to diagnose, especially in the 2nd and 3rd trimester (i.e., March-September ), mainly due to changes in the location of the appendix that lead to atypical symptoms and even to misdiagnosis. 80% of pregnant women have pain in the right lower abdomen, but it can also be located on the right side, in the right lumbar fossa, and sometimes even in the right upper abdomen. 55-75% of cases have rebound pain, and 50-65% have muscle tension. These symptoms may be masked, but one should keep trying to detect them. A positive test for psoas major is very rare. 87% of patients have anorexia, nausea and vomiting, but these non-specific symptoms are very common in early pregnancy. Fever is present in only 50% of patients. Elevated leukocytes are a normal physiological manifestation of pregnancy with low sensitivity and specificity, while CRP may be normal. II. Diagnosis Ultrasound is an important diagnostic tool, especially in the first trimester of pregnancy. Its diagnostic value decreases during the 6th-9th months of pregnancy due to technical difficulties. The diagnostic accuracy of ultrasound depends mainly on the experience of the operator and therefore varies greatly, with sensitivity and specificity ranging from 50% to 100% and 33% to 92%, respectively. If ultrasound cannot diagnose appendicitis because it cannot clearly identify the appendix (whether normal or not), then MRI should be used as a second diagnostic method (MRI has a sensitivity of 100% and a specificity of 94%). If MRI is not available or unavailable, CT can be used as an alternative test. This is because the risk of not diagnosing appendicitis during pregnancy is much higher than the low and limited radiation risk of CT. The diagnostic accuracy of CT during pregnancy is similar to that of the normal population, with a sensitivity and specificity of 92% and 99%, respectively. Delayed diagnosis can lead to a significantly higher risk of complications. For example, appendiceal perforation has a 20-35% incidence of fetal loss compared to appendicitis without perforation (1.5%). Related studies have found that the incidence of appendiceal perforation can reach 43% when surgery is delayed beyond 24 h, whereas no appendiceal perforation occurs when surgical management is performed within 24 h of hospitalization. Among them, preterm delivery is the most common, with a rate of over 50% in the 6th-9th months of pregnancy, due to confined peritonitis that causes early contractions in 83% of pregnant women. III. Treatment The treatment of acute appendicitis in pregnant women is surgical removal of the appendix, and the management strategy depends on gestational age, severity of appendicitis, body mass index, history of previous abdominal surgery, and surgeon’s competence and preference. Regardless of gestational age, laparoscopic appendectomy is the standard first-line treatment for acute appendicitis in pregnant women. If open appendectomy is chosen, in the first to third trimester, the classic McKinsey incision can be chosen, but in the third to ninth trimester, the incision must be higher on the right side, or even a median epigastric incision can be chosen to obtain a better finding of the appendix. If extensive peritonitis is present, a median incision centered on the umbilicus should be chosen, allowing easy access to abdominal exploration and abdominal irrigation.