Effect of body weight on early hormone levels in singleton pregnancies resulting in delivery after in vitro fertilization

Increasing body weight is associated with significantly lower early pregnancy levels of human chorionic gonadotropin and progesterone after blastocyst single-embryo transfer.

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Volume 110, Issue 7, Pages 1311–1317


Rachel B. Mejia, D.O., Taylor W. Cox, B.A., Edward B. Nguyen, M.D., Karen M. Summers, M.P.H., C.H.E.S., Patrick Ten Eyck, Ph.D., Amy E. Sparks, Ph.D., Bradley J. Van Voorhis, M.D.



To evaluate which clinical characteristics influence early maternal β-human chorionic gonadotropin (hCG) and progesterone levels in in vitro fertilization (IVF) pregnancies.


Retrospective cohort analysis.


Academic medical center.


Women with a live birth after single-blastocyst embryo transfer in either a fresh or frozen cycle between 2004 and 2017, comprising 1,282 pregnancies in 1,057 patients.



Main Outcome Measure(s)

The initial human chorionic gonadotropin concentration (β-hCG1) measured a mean of 10 days (range: 9–12 days) after embryo transfer, the rate of increase in β-hCG concentrations, and progesterone concentration, with all analyses controlled for number of days between the embryo transfer and the β-hCG1 measurement.


The clinical factor that positively influenced the β-hCG1 level in the fresh cycle was the stimulation type (antagonist cycle higher than long agonist cycle). The clinical factors that negatively influenced both fresh and frozen cycle β-hCG1 were lower embryo quality and increasing body weight. Increasing weight negatively impacted progesterone levels in both fresh and frozen cycles. A 100 lb (45.4 kg) difference in weight was associated with a 34.8% reduction in β-hCG1 for both fresh and frozen cycle pregnancies. The rate of increase in β-hCG was unaffected by body weight. A 100 lb (45.4 kg) difference in weight was associated with a 53.3% and a 32.8% reduction in progesterone in fresh and frozen cycles, respectively.


Increasing body weight is associated with significantly lower β-hCG and progesterone concentrations in early pregnancy after blastocyst single-embryo transfer in both fresh and frozen cycles. Clinicians should consider this when evaluating these hormone levels for prognostic and diagnostic purposes.

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Fertility and Sterility

Editorial Office, American Society for Reproductive Medicine

Fertility and Sterility® is an international journal for obstetricians, gynecologists, reproductive endocrinologists, urologists, basic scientists and others who treat and investigate problems of infertility and human reproductive disorders.