Effects of CO2 pneumoperitoneum in pregnant ewes

Laparoscopy has been considered a relative contraindication in pregnant patients because the CO2 pneumoperitoneum may cause maternal and/or fetal hypotension, acidosis, hypercarbia, hypoxia, changes in cardiac output, or uterine artery blood flow. These potential changes were studied in an established animal pregnancy model. Twelve gravid ewes (116-120 days gestation) underwent catheterization of maternal femoral artery and vein, fetal hindlimb artery and vein, insertion of a uterine artery flow probe, and pulmonary artery catheter. Six animals underwent creation of a CO2 pneumoperitoneum (10 mm Hg for 30 min; 15 mm Hg for 30 min). Six control animals were studied without a pneumoperitoneum. The following parameters were recorded at baseline and at preset time points: cardiac output (CO), uterine blood flow (UtBF), amniotic cavity pressure (ACP), end-tidal CO, (Et CO2), maternal and fetal heart rate (HR), blood pressure (BP), and lactate, glucose, and arterial blood gasses. Percent change at each time point compared to baseline was determined for each variable. Statistical significance was determined by repeated measures analysis of variance. No changes were found between study and control animals in maternal BP; CO; lactate, glucose, oxygenation, or fetal HR; oxygenation, lactate, or glucose. Statistically significant differences (P < 0.01) between study and control animals were noted in ACP, Et CO2, MHR, UtBF, FBP, and Maternal/fetal pH, PCO2. All ewes delivered healthy lambs at full gestation. A CO2 pneumoperitoneum up to 15 mm Hg pressure in gravid ewes causes increased intrauterine pressure, decreased UtBF, and induces maternal and fetal acidosis. Despite these intraoperative deleterious effects, long-term fetal well being was not effected.