Changes in follicular fluid gas and pH during carbon dioxide pneumoperitoneum for laparoscopic aspiration and their effect on human oocyte fertilizability.

OBJECTIVE

To determine changes in follicular fluid (FF) gases and acidity (pH) during either ultrasound (US)-guided or laparoscopic aspiration under carbon dioxide (CO2) pneumoperitoneum and relate the findings to the outcome of oocyte fertilization in vitro.

DESIGN

A prospective study carried out over a limited period of 1 month during which test FF samples were obtained without direct exposure to CO2 or air.

SETTING

Within the assisted pregnancy program setting at the Human Reproductive Biology Unit at the Soliman Fakeeh Hospital.

PATIENTS: Infertile women undergoing either laparoscopic or US guided follicular aspiration for the purpose of in vitro fertilization treatment.

INTERVENTION: Laparoscopic follicular aspiration under 100% CO2 pneumoperitoneum or transurethral US-guided follicular aspiration.

RESULTS

Mean FF carbon dioxide partial pressure (pCO2) and oxygen partial pressure (pO2) were significantly higher in those aspirated at laparoscopy compared with those obtained by US-directed aspiration. The mean FF pH in the laparoscopic group was as a consequence significantly lower than in the US group. Oocyte fertilizability was significantly reduced in the laparoscopic aspiration group compared with the US group. This was more pronounced when the fertilization rate of the last recovered oocytes from the groups were compared. No difference was observed in the post fertilization embryonic development between the two groups.

CONCLUSION

One hundred percent pneumoperitoneum leads to changes in FF that adversely affect oocyte fertilizability in a time-dependent manner. The use of US-directed procedure is advocated for all patients undergoing follicular aspiration in assisted pregnancy program. Where this is not feasible, the duration of CO2 pneumoperitoneum should be minimized.