Related Experiment Video
Updated: Aug 16, 2026
12:17
The 4-vessel Sampling Approach to Integrative Studies of Human Placental Physiology In Vivo
Published on: August 2, 2017
Maternal plasma osteoprotegerin concentration in normal pregnancy
Joon-Seok Hong1, Joaquin Santolaya-Forgas, Roberto Romero
1Perinatology Research Branch, National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, USA.
American Journal of Obstetrics and Gynecology
|September 15, 2005
Summary
Maternal plasma osteoprotegerin (OPG) levels increase significantly by the third trimester of pregnancy. This suggests OPG plays a role in regulating bone turnover during gestation.
Area of Science:
- Reproductive Endocrinology
- Bone Metabolism
- Maternal-Fetal Medicine
Background:
- Pregnancy significantly alters calcium metabolism due to fetal skeletal development, particularly in the third trimester.
- Osteoprotegerin (OPG) is a key regulator of bone remodeling by inhibiting Receptor Activator of Nuclear Factor-kappaB Ligand (RANKL).
Purpose of the Study:
- To investigate changes in maternal plasma OPG concentrations throughout normal pregnancy.
- To determine the relationship between gestational age and OPG levels.
Main Methods:
- A cross-sectional study involving 433 women (40 nonpregnant, 393 pregnant).
- Pregnant participants were categorized into four gestational age groups (11-14, 15-18, 27-30, and 37-42 weeks).
- Plasma OPG concentrations were quantified using a sensitive immunoassay, and nonparametric statistics were applied.
Main Results:
- Osteoprotegerin (OPG) was detectable in all participants' plasma.
- Median OPG concentrations were significantly elevated in the third trimester (6.63 pmol/L) compared to early pregnancy (3.98 pmol/L, P < .001).
- No significant differences in OPG levels were observed between nonpregnant women and those in the first or second trimesters.
Conclusions:
- Maternal plasma OPG concentration increases notably by the third trimester of pregnancy.
- These findings suggest a potential role for OPG in modulating bone turnover during pregnancy.
Related Concept Videos
01:27Ovarian Cycle
The menstrual cycle includes a critical component known as the ovarian cycle, which undergoes two main phases each month—the follicular phase and the luteal phase. The follicular phase is variable and averaging around 14 days. Ovulation, triggered by a surge in luteinizing hormone (LH), marks the transition between the two phases. The second phase, the luteal phase, is relatively consistent, lasting approximately 14 days, and is marked by the activity of the corpus luteum. While a cycle length...
02:07Oogenesis
In human women, oogenesis produces one mature egg cell or ovum for every precursor cell that enters meiosis. This process differs in two unique ways from the equivalent procedure of spermatogenesis in males. First, meiotic divisions during oogenesis are asymmetric, meaning that a large oocyte (containing most of the cytoplasm) and minor polar body are produced as a result of meiosis I, and again following meiosis II. Since only oocytes will go on to form embryos if fertilized, this unequal...