O&G Forum

OBSTETRICS & GYNAECOLOGY FORUM 2022 | ISSUE 3 | 29 Figure 1: Causes of acute abdomen in pregnant women by organ system 3 HELLP = haemolysis,elevated liver enzymes,low platelet count OBSTETRIC CAUSES NON OBSTETRIC CAUSES • Miscarriage • Ectopic pregnancy • Placental abruption • Preterm labour • Severe pre-eclampsia and HELLP* syndrome • Uterine rupture Gynaecological • Adnexal mass or ovarian cyst • Adnexal torsion • Uterine leiomyoma • Endometriosis • Pelvic in ammatory disease Gastrointestinal • Appendicitis • In ammatory bowel disease • Intestinal obstruction • Gastroesophageal re ux • Peptic ulcer disease • Splenic rupture Hepatobiliary • Cholelithiasis or choledocholithiasis • Acute cholecystitis • Acute pancreatitis • Hepatitis • Acute fatty liver of pregnancy Genitourinary • Hydronephrosis of pregnancy • Urolithiasis • Pyelonephritis • Cystitis Vascular • Gonadal vein thrombosis • Mesenteric vein thrombosis • Gonadal vein syndrome • Aneurysm rupture • Vasculitis Anatomical changes in pregnancy a ecting the diagnosis of acute abdomen e mechanical stretching and loss of elasticity of the abdominal muscle bres by the gravid uterus in uence the signs of peritoneal irritation, such as muscle guarding. 4 e gravid uterus causes displacement of adjacent intra-abdominal viscera from their normal position, causing a shi of the stomach, omentum, appendix and intestines upward and laterally. e appendix can move into the right upper quadrant and lies closer to the gall bladder at term with narrowing and mechanical compression of the colon. 5,6 e displacement of the omentum interferes with signs of peritonitis. e adnexa lie posterior to the gravid uterus from the second trimester, making palpation of ovarian pathology only possible by vaginal examination. e gravid uterus also compresses the ureters, causing hydroureter and hydronephrosis, mimicking urolithiasis. 6 In pregnancy, the physiological changes of cardiovascular, respiratory, gastrointestinal, renal, haematological and endocrine systems allow for the development of the foetus and the demands on the mother for childbirth. e total white blood cell count is elevated in pregnancy, which makes it less useful in the clinical evaluation of in ammation.1 Furthermore, there is an increase in plasma volume to red blood cell volume, which leads to a fall in haemoglobin concentration, haematocrit and red blood cells. In addition to an increased heart rate, cardiovascular changes make the clinical evaluation of haemorrhage challenging. 7 In terms of gastrointestinal changes, nausea and vomiting are common complaints in 50-90% of pregnancies, besides being one of acute abdomen presentation. 8 Serum amylase levels change in pregnancy, making the interpretation of results challenging in pancreatitis. 9 A clinician’s awareness of physiological and anatomical changes and the landmark displacement in pregnancy will aid in early diagnosis and prompt surgical intervention leading to better maternal and perinatal outcomes. Aetiologies Pregnancy-related causes could be physiological or pathological. Stretching of the round ligament is a physiological condition causing cramping or stabbing pain in the lower abdomen in 10- 30% of pregnancies; it is a diagnosis of exclusion and responds well to analgesia. 9 Braxton-Hicks contractions cause irregular abdominal pain in frequency and intensity, starting from the second half of pregnancy, which is usually misdiagnosed as labour. 9 Abdominal pain in early pregnancy may be due to miscarriage or an ectopic pregnancy. Patients present with a history of amenorrhoea, pain and bleeding. In addition to the history, a vaginal examination is a crucial assessment to reach the diagnosis and an ultrasound to con rm the diagnosis. In the second half of pregnancy, preterm labour pain is characteristic with increasing severity and associated with a show and cervical changes. Non-haemorrhagic obstetric shock can be attributed to pulmonary thromboembolism, amniotic uid embolism, acute uterine inversion and sepsis. Although these complications do not occur frequently, they are associated with most maternal deaths in the developed world. 10,11 When pulmonary thromboembolism is indicated based on clinical presentation, it should initially be managed with heparin, and unbiased investigations should be conducted. Upon veri cation of the diagnosis, heparin therapy is usually maintained until delivery, with anticoagulation continued postpartum by administration of either warfarin or heparin.10 Emboli occurring in the amniotic uid embolism is an exceptional pregnancy-related complication that usually present during the peripartum period. Amniotic uid embolism management includes maternal oxygenation, sustaining cardiac output and blood pressure, and control of any concomitant coagulopathy. 11 Acute uterine inversion is most frequently related to mismanagement of the third stage of labour. 12 Shock associated with uterine inversion results from neurogenic mechanisms, although extensive haemorrhagemay also occur. emanagement of acute uterine inversion requires maternal resuscitation and repositioning of the uterus either manually, surgically or by means of hydrostatic pressure. 12 Genital tract sepsis is a persistent major cause of maternal death, with prolonged rupture of the foetal membranes most frequently identi ed as the primary predisposing factor. 13 Septic shock in pregnancy is managed by resuscitation, detecting of the source of infection andmodi cation of the systemic in ammatory reaction. 13 In placenta abruption, a patient presents with abdominal pain and vaginal bleeding, and on examination, the uterus is tender and hard with di culty in palpating the foetus. A haematoma might be visible on ultrasound examination, and foetal loss might occur. Diagnosis is mainly clinically and supported by blood results showing low haemoglobin level, renal failure and coagulopathy. O&G Forum 2022; 32: 28-31 CASE REPORT