Acute Abdomen in Pregnancy (AAP) - Causes, Diagnosis, and Management

What Is Acute Abdomen and How Does It Affect Pregnancy?

Acute abdomen is any severe acute intra-abdominal condition accompanied by pain, tenderness, and muscular rigidity and for which emergency surgery must be considered. The diagnosis and treatment of an acute abdomen during pregnancy provide special challenges. Acute abdominal pain during pregnancy (AAP) can develop due to obstetric reasons and reasons unrelated to pregnancy.

The diagnostic process for acute abdomen during pregnancy can be challenging due to the altered clinical presentations imposed by the anatomical and physiological changes of gestation, as well as the reluctance to utilize certain radiological studies out of concern for the fetus. Delays in diagnosis and treatment may adversely affect the mother and fetus.

What Are the Causes of Acute Abdomen in Pregnancy (AAP)?

The causes of AAP are classified under the following categories,

1. Obstetric (Pregnancy-Related Causes)-

• Early Pregnancy-

  • Miscarriage.

  • Ectopic pregnancy.

  • Molar pregnancy.

  • An ovarian cyst (torsion, hemorrhage, rupture).

  • Degeneration of uterine fibroids.

  • Round ligament pain.

• Late Pregnancy-

  • Placental abruption.

  • Acute fatty liver of pregnancy (AFLP).

  • Abdominal pregnancy.

  • HELLP (hemolysis, elevated liver enzymes, low platelet count) syndrome.

  • Fibroid degeneration.

  • Ruptured uterus.

  • Fallopian tube torsion.

  • Ruptured rectus muscle.

  • Uterine torsion.

  • Polyhydramnios.

  • Intraperitoneal bleed.

  • Symphysis diastasis.

2. Non-obstetric (Non-pregnancy-Related Causes)-

• Surgical-

  • Appendicitis.

  • Biliary colic.

  • Cholecystitis.

  • Peptic ulcer.

  • Acute pancreatitis.

  • Intestinal obstruction.

  • Urolithiasis.

  • Inflammatory bowel disease (IBD).

  • Trauma.

  • Rupture aneurysm.

• Medical-

  • Gastroenteritis.

  • Porphyria.

  • Deep vein thrombosis.

  • Sickle cell crisis.

3. Extra-Abdominal Causes-

• Gastroesophageal reflux disease (GERD).

• Acute cystitis.

• Gallbladder disease.

• Musculoskeletal pain.

• Acute pyelonephritis.

4. Conditions Exacerbated by Pregnancy-

• Cardiac pain.

• Pleuritic pain.

• Non-specific abdominal pain (NSAP).

• Herpes zoster infection.

• Psychological manifestations of drug abuse or withdrawal.

How Is Acute Abdomen in Pregnancy Diagnosed?

• First, a thorough clinical evaluation (history and physical examination) would be conducted, and blood would be sampled for regular and specific tests.

• Ultrasonography - The imaging technique that is most frequently used to assess a pregnant abdomen is probably ultrasound. It is simple to evaluate the kidneys, pancreas, and gallbladder of the mother. Limitations are caused by changes in the body's habitus as the pregnancy progresses. Ultrasonography also aids in the determination of gestational age and fetal viability, the exclusion of congenital disorders, the measurement of amniotic fluid volume, and the evaluation of fetal health. When decisions about a delivery, mode of delivery, and the administration of tocolytics and steroids must be made, this information may be crucial in the later management of a gravid patient with an acute abdomen.

• Radiography and Computed Tomography (CT) - Where medically necessary, diagnostic radiographic procedures should be carried out during pregnancy; however, when alternatives devoid of ionizing radiation are available, radiography should be given consideration. Ionizing radiation should only be used when medically necessary. Exposure to such radiation should be restricted to the greatest extent possible without compromising patient care due to the potential link between antenatal radiation exposure and pediatric cancer.

• Magnetic Resonance Imaging (MRI)- MRI uses magnets rather than ionizing radiation to change the energy state of hydrogen protons and may be useful in evaluating the maternal abdomen and the fetus. Even though there have been no known adverse effects on fetuses, the National Radiological Protection Board cautioned against using MRI during the first trimester. Noncontrast MRI is increasingly used as a secondary diagnostic after ultrasonography to assess pregnant women with abdominal pain.

How Is Acute Abdomen in Pregnancy Treated?

• A thorough clinical evaluation (history and physical examination) and blood sample collection would be the first steps in the procedure.

• The initial assessment would be hemodynamic stability. Some Patients may need emergency surgical intervention. Consultations from several disciplines should be requested immediately. Patients that need emergency surgical intervention are-

  • Hemodynamically unstable.

  • Show signs of clinical deterioration.

  • Are about to go into shock.

  • Have a high index of suspicion for peritonitis.

  • Have conclusive evidence of peritonitis.

• Those with stable hemodynamics can be evaluated depending on the location of their abdomen pain in relation to potential etiologies. These patients can be further divided into urgent and nonurgent groups, with obstetric or non-obstetric etiologies based on clinical, laboratory, and radiographic examination.

• Emergency surgery might be needed in severe cases.

• Conservative therapy (non-operative management) should be the first approach in non-emergency situations along with careful clinical status monitoring. Elective surgery could be scheduled during the postpartum period if things become better.

• In some cases, recurrence of the disease process may necessitate immediate surgery.

Surgical Considerations:

• Timing of Surgery - It is recommended to postpone surgery until after the pregnancy is over if it is necessary yet deemed elective. In addition, if pregnancy-related surgery is considered necessary, the risk of spontaneous loss and dangers connected with medications like anesthetic agents are lower in the second trimester than in the first. Preterm labor and delivery are also less likely to occur in the second trimester than in the third. The procedure needs to be done in the second trimester, if at all possible.

• Laparoscopy During Pregnancy - Laparoscopy is increasingly used in treating and evaluating acute abdomen. The uterus must be handled with care. The position of the trocar should be modified based on the size of the uterus. During the surgery, fetal heart tones should be monitored. The obstetrician and surgeon must collaborate closely to ensure the fetus’ health throughout the surgical process.

• Obstetric Concerns-

  • The most significant risk to the fetus in treating acute maternal intra-abdominal illness is preterm labor and delivery.

  • Tocolytics' preventive impact on these patients has yet to be established. Tocolytics should only be used with caution. If the gestational age is under 32 weeks, Indomethacin, magnesium sulfate, or beta-mimetics such as Ritodrine, and Terbutaline, may be administered. A tocolytic agent should only be used if there are no tocolytic contraindications, such as severe placental abruption, chorioamnionitis, or fatal abnormalities.

  • The patient should be closely watched, and any pulmonary issues should be kept in mind.

  • Glucocorticoids can be given to the mother to lower the risk of neonatal complications if premature delivery is expected. If the mother is at serious risk for a significant infection, glucocorticoids should be avoided.

  • Obstetric indications should also be taken into consideration when choosing the delivery method. Delivery is advised if it is anticipated that continuing the pregnancy will result in maternal morbidity or mortality. If birth cannot be expected to improve the mother's condition, the patient should be treated while the fetus is still inside her.

Conclusion:

Acute abdomen in pregnancy may result from both obstetric and non-obstetric reasons. Life-threatening diseases may not present with classic symptoms. Radiological investigations should always start with nonionizing tests. If there is a clear clinical indication and no other option, investigations involving ionizing radiation, such as X-ray and CT (computed tomography) scans, should not be delayed, especially in situations where life is at risk. In some people, laparoscopic surgery is possible and safe.