Assessment of the Risk of Fetal Loss after the Coelocentesis Procedure Using a Baboon Model

Abstract

Objectives: The aims of this study were to gain some insight with regard to the safety of the coelocentesis procedure and, to determine pH, pCO₂, and base excess status of the extracoelomic fluid 40 days after fertilization. Methods: Twenty-eight timed-mated baboons from the breeding colony of the Biological Resource Laboratory at the University of Illinois at Chicago were studied. The initial 19 animals were used to determine the ultrasonographic relations between the different compartments of the gestational sac from 38 to 62 days of pregnancy. Under aseptic conditions, in 9 animals coelocenteses were then performed, under continuous transvaginal ultrasound guidance to avoid the amniotic or yolk sacs. Extracoelomic fluid (1–5 ml) was aspirated using 10-ml syringes. Only one attempt of sampling was performed in each of the 9 animals. Extracoelomic fluid pH, pCO₂, and base excess were compared with maternal femoral venous blood. Pregnancies were followed by transabdominal ultrasound evaluations on day 3 after the procedure and weekly until day 140 after fertilization. Results: Extracoelomic fluid could be aspirated easily using a 20-gauge needle. Only one pregnancy loss was detected within 3 days after the procedure. No complications occurred in the remaining 8 pregnancies. Extracoelomic fluid pH (7.45 ± 0.01) and pCO₂ (39.9 ± 2.4 mm Hg) were significantly different from maternal femoral venous blood pH (7.41 ± 0.01) and pCO₂ (47.1 ± 1.4 mm Hg; p < 0.02), while base excess values were similar. Conclusions: This preliminary study performed at 40 days after fertilization in the baboon model suggests that the coelocentesis procedure is technically simple and presents a relatively low risk to mother and fetus if a 20-gauge needle is used and the amount of aspirated extracoelomic fluid is <3 cm³. At this gestational age, the extracoelomic fluid is more alkalotic than maternal femoral venous blood.

Prenatal Paternity Testing Using DNA Extracted from Coelomic Cells

“…For example, in Greece up to 10% of the population are carriers of ß-thalassaemia and in women carriers of the disease the knowledge of the actual father is crucial. Previous studies have demonstrated that paternity exclusion can be performed with accuracy after CVS [12,13]. The results of this study have shown that the same methods can be used successfully in the DNA extracted from the coelomic cells, from at least 7 weeks of gestation.…”

Prenatal and preimplantation genetic diagnosis - a step in right path

“…The risk of a miscarriage related to the test is about 3 per cent [53]. Coelocentesis is a technically simple procedure which uses extracoelomic fluid as a sample, usually for an early prenatal diagnostic technique [54].…”

Prenatal Diagnosis of Hemoglobinopathies: From Fetoscopy to Coelocentesis

“…This author reports that the difficulty for the aspiration of coelomic fluid may require an increased number of multiple punctures further compromising the safety. Santolaya-Forgas et al, 100 examining the safety of coelocentesis in baboons, reported that this procedure might be safe for the pregnancy if it is performed at about 40 days of gestation using a 20 G needle and if less than 3 mL of coelomic fluid is aspirated. In another study, Ross et al 99 reported the results of coelocentesis in 107 women and 337 controls, showing that the risk of fetal loss between 7 and 9 weeks of gestation is about 2%, and comparable to the fetal loss following CVS.…”