植入胚胎之細胞數會影響植入後12天偵測HCG之濃度
細胞數越多, HCG濃度越高
取出卵子數越多(>20), HCG濃度越低???

Hum Reprod. 2015 Dec;30(12):2758-63. doi: 10.1093/humrep/dev269. Epub 2015 Oct 27.

Maternal hCG concentrations in early IVF pregnancies: associations with number of cells in the Day 2 embryo and oocytes retrieved.

Tanbo TG1, Eskild A2.

Author information

Abstract

STUDY QUESTION:

Do number of cells in the transferred cleavage stage embryo and number of oocytes retrieved for IVF influence maternal hCG concentrations in early pregnancies?

SUMMARY ANSWER:

Compared with transfer of a 2-cell embryo, transfer of a 4-cell embryo results in higher hCG concentrations on Day 12 after transfer, and more than 20 oocytes retrieved were associated with low hCG concentrations.

WHAT IS KNOWN ALREADY:

Maternal hCG concentration in very early pregnancy varies considerably among women, but is likely to be an indicator of time since implantation of the embryo into the endometrium, in addition to number and function of trophoblast cells.

STUDY DESIGN, SIZE, DURATION:

We followed 1047 pregnancies after IVF/ICSI from oocyte retrieval until Day 12 after embryo transfer. Women were recruited in Norway during the years 2005-2013.

PARTICIPANTS/MATERIALS, SETTING, METHODS:

Successful pregnancies after transfer of one single embryo that had been cultured for 2 days were included. Maternal hCG was quantified on Day 12 after embryo transfer by chemiluminescence immunoassay, which measures intact hCG and the free β-hCG chain. Information on a successful pregnancy, defined as birth after >16 weeks, was obtained by linkage to the Medical Birth Registry of Norway.

MAIN RESULTS AND THE ROLE OF CHANCE:

Transfer of a 4-cell embryo resulted in higher maternal hCG concentrations compared with transfer of a 2-cell embryo (134.8 versus 87.8 IU/l, P < 0.05). A high number of oocytes retrieved (>20) was associated with low hCG concentrations (P < 0.05).