Defining the rise of serum HCG in viable pregnancies achieved through use of IVF.
BACKGROUND
We aimed to characterize the rate of HCG rise associated with viable IVF pregnancies, and to evaluate the association between HCG rise and potentially influential factors.


METHODS
We performed a retrospective cohort analysis of all viable pregnancies achieved through IVF at two centres between January 1999 and March 2004.


RESULTS
Of the 455 pregnancies resulting in live births, 391 met inclusion criteria and contributed a total of 1052 HCG values. Using random effects models, the best pattern to describe the rise of log HCG was quadratic with the rate of increase slowing at 24 days post-oocyte retrieval. Limiting the analysis to measurements below the discriminatory zone, the linear model adequately characterized the profile. The average slope was 0.403, yielding a predicted increase of 1.50 (50% increase) in 1 day and 2.24 (124%) in 2 days. In the final model, absolute HCG values, but not rate of rise, were significantly higher for twins and triplets and significantly lower for patients with BMI>30 kg/m2.


CONCLUSIONS
The HCG profile of viable pregnancies conceived with IVF is quadratic with an earlier plateau than has been reported for non-IVF pregnancies. The average rate of rise is comparable to previous estimates in symptomatic spontaneous conceptions.
Chung
Karine
K
University of Pennsylvania, Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility, 3701 Market Street, Suite 800, Philadelphia, PA 19104, USA. karinech@usc.edu
Sammel
Mary D
MD
Coutifaris
Christos
C
Chalian
Raffi
R
Lin
Kathleen
K
Castelbaum
Arthur J
AJ
Freedman
Martin F
MF
Barnhart
Kurt T
KT
D015415:Biomarkers / Q000097:blood*; D006063:Chorionic Gonadotropin / Q000097:blood*; D015331:Cohort Studies; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D018579:Patient Selection; D011247:Pregnancy; D011256:Pregnancy Outcome; D015203:Reproducibility of Results; D012189:Retrospective Studies
D015415:Biomarkers; D006063:Chorionic Gonadotropin