Aspiration of oocytes for in-vitro fertilization.

Human Reproduction Update (Impact Factor: 10.17). 2(1):77-85.
Source: PubMed


An aspiration system, incorporating a regulated vacuum pump, was used to examine, in vitro, some factors that may affect oocyte collection. In an open aspiration system, as the length of the needle was increased, or the internal diameter decreased, the velocity (and flow rate) of aspirated fluid decreased. There was a difference, however, between experimental flows and those predicted by Hagen-Poiseuille's Law. Upon application of vacuum to a closed aspiration system, employing isolated bovine ovaries, there was an initial rapid increase in the collection tube vacuum to 85% of the selected pump vacuum followed by a more gradual rise to 100%. The vacuum within the needle similarly rose rapidly to approximately half the selected vacuum, while the vacuum at the needle tip was approximately 5% of selected vacuum. The vacuums throughout the system briefly equilibrated as maximum flow/velocity was reached. Flow/velocity slowed dramatically as the follicle collapsed, and stopped as the needle tip was blocked. If vacuum was maintained during the withdrawal of the needle from the follicle, there was a dramatic forward flow of fluid toward the collection tube. The morphological appearance of bovine cumulus after in-vitro aspiration was generally unaltered by vacuums commonly utilized in oocyte collection, providing the cumulus was regular, compact and refractile. The cumulus was less resistant to aspiration if it was damaged or had degenerated. These results suggest that an intact cumulus may offer protection during oocyte collection.

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    • "FF is composed of colloid proteins and mucopolysaccharides [31] and consequently, shows a variable degree of viscosity [32]. This viscosity causes a speed gradient when fluids pass in tubular systems, with the flux in the inner part of the tube being faster than that in the periphery [33]. Such phenomenon causes the fluids to spread over the inner surface of the aspiration circuits. "
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    ABSTRACT: Most studies on granulosa cell (GC) function in cattle have been performed using GC and follicular fluid (FF) samples collected from slaughterhouse ovaries. Using this approach, the follicular developmental stage and functional status are unknown and indirectly inferred, limiting data interpretation. Ultrasound-guided follicle aspiration has previously been used to recover GC or FF samples, but this was mostly carried out in large follicles or pools of small follicles, without recording the efficiency of recovery. The present study was aimed at adapting and evaluating an ovum pick-up (OPU) system for the in vivo recovery of FF and GC from individual follicles of different diameters. In the first trial, the losses of fluid inside the tubing system were calculated using a conventional or an adapted-OPU system. Blood plasma volumes equivalent to the amount of FF in follicles of different diameters were aspirated using a conventional OPU Teflon circuit. The OPU system was then adapted by connecting 0.25 mL straws to the circuit. A second trial evaluated the efficiency of FF recovery in vivo. Follicles ranging from 4.0 to 16.8 mm in diameter were aspirated individually using the conventional or adapted-OPU systems. A third trial assessed the in vivo recovery of GC and the subsequent amount of RNA obtained from the follicles of different diameters from Holstein and Gir cattle. In Trial I, the plasma recovery efficiency was similar (P > 0.05) for the volumes expected for 12 and 10 mm follicles, but decreased (P < 0.05) for smaller follicles (45.7+/-4.0%, 12.4+/-4.3% and 0.0+/-0.0% for 8, 6, and 4 mm follicles, respectively). Using the adaptation, the losses intrinsic to the aspiration system were similar for all follicle diameters. In Trial II, the expected and recovered volumes of FF were correlated (r = 0.89) and the efficiency of recovery was similar among follicles <12 mm, while larger follicles had a progressive increase in FF losses that was not related to the tubing system. In Trial III, the number of GC and amount of RNA obtained were not affected (P > 0.05) by follicle size, but differed according to breed (615,054+/-58,122 vs 458,095+/-36,407 for Holstein and Gir, respectively; P < 0.05). The adapted-OPU system can be successfully used for the in vivo collection of FF and GC from follicles of different diameters. This will enable further endocrine, cellular, and gene expression analyses.
    Full-text · Article · Aug 2013 · Reproductive Biology and Endocrinology
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    • "A 16 gauge double lumen needle (DC1S/ 16G/Clarendon, Casmed, Surrey, UK) was used to recover the oocytes using a reduced aspiration pressure compared with conventional IVF of only 80 mmHg, as described by Trounson et al. (1994b). Other aspects of the collection technique were similar to those used in routine IVF (Horne et al., 1996). The diameters of all follicles ജ4 mm were measured in two planes and recorded. "
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    ABSTRACT: The objective of this study was to investigate the effect of follicle stimulating hormone (FSH) priming on the in-vitro maturation (IVM) of human oocytes from healthy ovaries using a chemically defined culture system. Seventeen patients donating oocytes for research received a truncated course of 600 IU FSH over 5 days and a further control group of nine patients received no FSH treatment. Mid-follicular phase cumulus-enclosed oocytes (n = 160) were aspirated from follicles < or =4 mm diameter under transvaginal ultrasound guidance and were cultured for 48 h in microdrops of medium containing 10 mIU/ml FSH and 100 mIU/ ml human chorionic gonadotrophin (HCG). The results demonstrated that human oocytes will efficiently undergo IVM under serum-free conditions. After mild FSH stimulation, a greater number of cumulus-enclosed oocytes was collected, and following culture, a lower rate of degeneration was observed. Significantly more oocytes completed nuclear maturation to metaphase II following FSH stimulation (71.1 versus 43.5%). In conclusion, a truncated course of FSH stimulation in vivo improved the oocyte maturation rate in vitro, giving a mean of 4.8+/-0.7 metaphase II oocytes per patient compared with only 2.1+/-0.7 from control patients, thus yielding more mature oocytes for future IVF treatment.
    Full-text · Article · Dec 1998 · Human Reproduction
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    Preview · Article · Nov 1999 · Human Reproduction
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