The incidence of surgical disease is the same in pregnant and nonpregnant patients. A total of 1.5–2% of all pregnancies undergo nonobstetric surgical intervention. Presenting symptoms of surgical diseases are often similar in pregnant and nonpregnant patients. The most common surgical disorders in pregnancy are appendicitis, cholecystitis, intestinal obstruction, adnexal torsion, trauma, and cervical and breast disease. Limited imaging can be performed during pregnancy if results would significantly alter management. The second trimester is the preferred time for nonurgent surgery. Surgery should not be delayed in any trimester if systemic infection or severe disease is suspected, as this is associated with higher risk to mother and fetus. Whenever possible, regional anesthesia should be performed. Pregnancy does not change prognosis, which depends largely on the extent of disease at diagnosis. A multidisciplinary approach with maternal–fetal medicine, surgery, anesthesia, and neonatology during treatment planning is invaluable to ensure optimal outcomes for both the mother and fetus.
Surgical interventions other than caesarean section are performed in 1.5–2.0% of all pregnancies. Altered anatomy and physiology and potential risks to the mother and fetus make diagnosis and management of surgical disorders more difficult during pregnancy. The interests of mother and fetus are best served by the obstetrician's active participation with the anesthesiologist, neonatologist, and general surgeon throughout the mother's diagnosis and management of a nonobstetric surgical disorder. It is imperative that the obstetrician be well informed about the ways in which surgical disorders influence pregnancy and vice versa, the risks of diagnostic and therapeutic procedures to the fetus, and appropriate management of preterm labor in the immediate postoperative period.
Surgical disorders can be either incidental to or directly related to the pregnancy. Diagnostic evaluation requires gentle, sensitive elicitation of physical signs, at times without sophisticated diagnostic aids that involve risk to the developing fetus. Good judgment regarding the timing, methods, and extent of treatment is important. In the absence of peritonitis, visceral perforation, or hemorrhage, surgical disorders during gestation generally have little effect on placental function and fetal development.
Pregnancy is accompanied by physiologic and anatomic changes that alter the evaluation and management of the surgical patient. The 30–50% increase in plasma volume during pregnancy affects cardiac output and may alter drug distribution and laboratory test results. Red cell mass increases but not as much as the plasma volume, resulting in a slight physiologic anemia. Colloid osmotic pressure is decreased during pregnancy. Increased interstitial fluid is seen as mild edema, particularly in the lower extremities. Systemic vascular resistance decreases during pregnancy. Systolic and diastolic blood pressures characteristically drop during the early second trimester, with a gradual return to baseline by term. Functional pulmonary residual capacity decreases due to limitation of diaphragmatic excursion. Minute ventilation increases due to increased tidal volume and respiratory rate. A compensated mild respiratory alkalosis exists. Increased renal blood flow is evidenced by increased glomerular filtration rate and decreased serum creatinine and blood urea nitrogen values. Gastrointestinal motility is diminished, ...