Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2019 Mar;26(3):412-419.
doi: 10.1177/1933719118776792. Epub 2018 Jun 3.

Effect of Mode of Conception on Maternal Serum Relaxin, Creatinine, and Sodium Concentrations in an Infertile Population

Affiliations

Effect of Mode of Conception on Maternal Serum Relaxin, Creatinine, and Sodium Concentrations in an Infertile Population

Frauke von Versen-Höynck et al. Reprod Sci. 2019 Mar.

Abstract

Objective: To investigate how the mode of conception affects maternal relaxin, creatinine, and electrolyte concentrations.

Background: Pregnancies achieved by fertility treatment often begin in a nonphysiologic endocrine milieu with no corpus luteum (CL) or with many corpora lutea. The CL produces not only estradiol and progesterone but is also the sole source of relaxin in early pregnancy, a hormone that may contribute to maternal systemic and renal vasodilation. There is limited data about maternal physiology in early pregnancy during fertility treatment, and studies have rarely considered the potential effect of the absence of the CL. To begin to address this gap in knowledge, we sought to investigate how the mode of conception affects maternal relaxin, creatinine, and electrolyte concentrations.

Methods: One hundred eighty-four women who received care at an academic infertility practice provided serum samples. Levels of relaxin 2, creatinine, and electrolytes were compared between 4 groups defined on the basis of mode of conception which corresponded to categories of CL number: (1) absence of the CL, (2) single CL, (3) multiple CL from ovarian stimulation not including in vitro fertilization (IVF), and (4) multiple CL from IVF with fresh embryo transfer.

Results: Relaxin-2 levels were undetectable in patients lacking a CL. Creatinine, sodium, and total CO2 levels were significantly higher in the 0 CL group (relaxin absent) compared to all other groups (relaxin present). Compared to clomiphene, use of letrozole was associated with a lower relaxin level.

Conclusion: Early creatinine and sodium concentrations are increased in the absence of relaxin. Given the increasing utilization of frozen embryo transfer, further studies comparing programmed with natural cycles are warranted.

Keywords: assisted reproduction; corpus luteum; female infertility; pregnancy; relaxin.

PubMed Disclaimer

Conflict of interest statement

Declaration of Conflicting Interests: The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: KPC discloses use patents for relaxin. All other authors declare no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Figures

Figure 1.
Figure 1.
Creatinine (A), Na+ (B), and tCO2 (C) levels depending on relaxin status (absent vs present) in singleton pregnancies. Box plots represent median and 25th and 75th percentile. Creatinine (P < .001), sodium (P = .011), and tCO2 (P = .001) concentrations are significantly higher in the absence of relaxin compared to the presence of relaxin.

References

    1. Chapman AB, Abraham WT, Zamudio S, et al. Temporal relationships between hormonal and hemodynamic changes in early human pregnancy. Kidney Int. 1998;54(6):2056–2063. - PubMed
    1. Petersen JW, Liu J, Chi YY, et al. Comparison of multiple non-invasive methods of measuring cardiac output during pregnancy reveals marked heterogeneity in the magnitude of cardiac output change between women. Physiol Rep. 2017;5(8):1–11. - PMC - PubMed
    1. Capeless EL, Clapp JF. Cardiovascular changes in early phase of pregnancy. Am J Obstet Gynecol. 1989;161(6 pt 1):1449–1453. - PubMed
    1. Robson SC, Hunter S, Boys RJ, Dunlop W. Serial study of factors influencing changes in cardiac output during human pregnancy. Am J Physiol. 1989;256(4 pt 2):H1060–H1065. - PubMed
    1. Chapman AB, Zamudio S, Woodmansee W, et al. Systemic and renal hemodynamic changes in the luteal phase of the menstrual cycle mimic early pregnancy. Am J Physiol. 1997;273(5 pt 2):F777–F782. - PubMed

Publication types