In a nutshell
This study investigated the number of mature oocytes (eggs) needed to produce top-quality embryos (TQE).
They found that at least 3 mature oocytes produced are associated with at least 1 TQE.
In vitro fertilization (IVF) first requires oocytes (eggs). They are retrieved by controlled ovarian stimulation (COS). COS involves taking drugs to stimulate oocyte maturation (OM). This also triggers release of oocytes for harvesting. The number of mature oocytes measures COS success. However the number of top quality embryos (TQEs) can be used to predict IVF success.
Embryos are fertilized oocytes from IVF. Quality is usually measured at Day 3 after fertilization. TQEs at Day 3 are associated with better pregnancy rates (PR). Recent studies also suggest that the number of mature oocytes harvested is associated with better PRs. It is unclear if there is an association between the number of mature oocytes and TQE in women undergoing IVF.
Methods & findings
This study included 170 women that underwent 210 IVF cycles. All women underwent a standard COS protocol. The number of mature oocytes retrieved was compared to TQEs after IVF.
There was a signifcant association between the number of mature oocytes retrieved and TQEs. Higher numbers of mature oocytes was associated with higher TQE. The moderate cut-off NMO for producing at least 1 TQE was 3, meaning that at least 3 mature oocytes were needed in order to have at least one TQE. The average number of TQEs obtained if there were at least 9 mature oocytes retrieved was 3.3.
The bottom line
The authors concluded that at least 3 mature oocytes needed to be retrieved to obtain at least 1 TQE.
The fine print
Women in this study were normal responders to COS. It is unclear if the cut-offs can apply to poor or high responders. The association with pregnancy rates was not analyzed. More studies are needed.
Published By :
Clinical and experimental reproductive medicine
Jul 21, 2020