Plasma volume variation across the menstrual cycle among healthy women of reproductive age: A prospective cohort study

Abstract

Increases in reproductive hormones like estrogen, play an important role in the remarkable increases in plasma volume observed in pregnancy. Accurate estimates of plasma volume expansion during pregnancy depend on correctly timing and measuring plasma volume in nonpregnant women. However, to date, there is no consensus on the pattern of plasma volume across the menstrual cycle. We prospectively measured plasma volume in 45 women across a single menstrual cycle. A urine‐based fertility monitor was used to time three clinic visits to distinct points in the menstrual cycle: the early follicular phase (~day 2), periovulation (~day 12), and the mid‐point of the luteal phase (~day 21)—based on a 28‐day cycle length. Healthy women aged 18–41 years with regular menstrual cycles and a healthy body weight were enrolled in the study. At each visit, blood samples were collected before and after injection of 0.25 mg/kg body weight of indocyanine green dye (ICG). Pre‐ and post‐ICG injection plasma samples were used to measure plasma volume. Preinjection samples were used to measure ovarian hormones and plasma osmolality. Mean plasma volume was highest during the early follicular phase (2,276 ± 478 ml); it declined to 2,232 ± 509 ml by the late follicular phase and to 2,228 ± 502 ml by the midluteal phase. This study found that overall variations in plasma volume are small across the menstrual cycle. Therefore, in clinical practice and research, the menstrual cycle phase may not be an important consideration when evaluating plasma volume among women of reproductive age.

Does Low Maternal Exposure to Per- and Polyfluoroalkyl Substances Elevate the Risk of Spontaneous Preterm Birth? A Nested Case–Control Study in China

“…We observed significantly higher PFOA concentrations in the first trimester than the second trimester in the control population, which is consistent with previous findings that maternal PFAS concentrations decreased with gestational age. , Although the causes for the phenomenon remain unclear, we suspected that the transplacental transfer of PFASs to the fetus and the expansion of blood volume during pregnancy could contribute to the decreasing of PFAS levels in maternal blood along with time. , …”

Removal of the influence of plasma volume fluctuations for the athlete biological passport and stability of haematological variables in active women taking oral contraception

“…Although the haematological variables, analysed weekly, remained remarkably stable, the repeated measures ANOVA revealed a significant difference for [Hb], HCT and RBC during Week 7. Interestingly, PV tended to be higher during the same week ( p = 0.05), whereas no significant time effect was observed over the 8 study weeks, which is in line with the small PV variations across the menstrual cycles recently reported by Aguree et al 50 However, those results need to be put in perspective because the measured biomarkers are prone to rather high physiological variability 51–55 . Potential fluctuations induced by the OCP cycle would, thus, be inferior to the one expected from the main confounding factors such as exercise, hypoxic or heat exposure.…”

A methodology for examining the association between plasma volume and micronutrient biomarker mass and concentration in healthy eumenorrheic women

“…Though our previous study reported a small non-significant decrease in plasma volume across the menstrual cycle, it is unknown how that may influence micronutrient biomarker concentrations and circulating mass ( Aguree et al., 2020 ). Future studies should be designed (with appropriate statistical power) to clarify whether PV influences micronutrient concentrations and how BMI and inflammation affect these relationships.…”