Blood Flow, Pelvic Circulation & Reproductive Health

The Fertility Class movement method is designed to support fertility, cycle and reproductive health, digitally accessible from anywhere. The Fertility Class movement sequences are rooted in the Aviva Method, a structured exercise program used for over 60 years to support fertility naturally, and alongside medical treatment.

Below is the peer-reviewed research behind the method's core mechanisms - pelvic circulation, nervous system regulation, and exercise intensity, along with a look at the research conducted on the Aviva Method specifically.

The Aviva Method and The Fertility Class Studies: BLOOD FLOW, PELVIC CIRCULATION & REPRODUCTIVE HEAL

Pelvic Blood Flow and Ovarian Function

Ovarian Blood Flow and Egg Quality

Research suggests that ovarian blood flow is closely associated with ovarian function and oocyte quality, particularly in women undergoing assisted reproductive technology (ART). Reduced ovarian vascularization and increased resistance indices have been linked with poorer ovarian function and reduced reproductive outcomes.

Lower ovarian blood flow is associated with reduced egg quality and function: https://pmc.ncbi.nlm.nih.gov/articles/PMC9929747 https://pmc.ncbi.nlm.nih.gov/articles/PMC5819322

Ovarian Blood Flow and Follicle Development

Adequate ovarian circulation plays an important role in follicular development and ovulation. Studies using Doppler ultrasound have shown that decreased ovarian blood flow may be associated with insufficient follicle maturation and lower success rates in assisted reproduction.

Decreased ovarian blood flow has been associated with poorer follicle maturation and ART outcomes: https://pmc.ncbi.nlm.nih.gov/articles/PMC3454957

The Fertility Class includes movement sequences that activate the lower abdominal and pelvic muscles surrounding the ovarian vascular supply, helping support healthy circulation in this region.

Pelvic Blood Flow and Uterine Function

Uterine Blood Flow and Implantation

Blood flow to the uterus is an important factor in implantation and early pregnancy. Reduced uterine perfusion has been associated with lower implantation rates and poorer reproductive outcomes in IVF populations.

Reduced uterine blood flow has been associated with lower implantation rates and pregnancy outcomes: https://pmc.ncbi.nlm.nih.gov/articles/PMC10133733

Uterine Artery Pulsation Index

Uterine artery blood flow resistance, measured by the pulsatility index (PI), is commonly used in reproductive medicine to evaluate uterine perfusion. Higher PI values are associated with reduced uterine blood flow and may correlate with lower success rates in assisted reproductive treatments.

A higher pulsation index has been linked to lower fertility and reduced ART success rates: https://pmc.ncbi.nlm.nih.gov/articles/PMC4696374

The movement sequences in The Fertility Class engage muscles in the pelvic and lower abdominal region, which may help support circulation to the uterus.

Pelvic Blood Flow and Endometrial Health

Endometrial Blood Flow and Implantation

Healthy blood flow to the uterine lining plays an important role in implantation. The endometrium must develop a rich blood supply to support embryo implantation and early pregnancy. Research using Doppler ultrasound has shown that women with stronger blood flow within the endometrium and surrounding tissue tend to have higher implantation and pregnancy rates during IVF treatment.

Women with detectable blood flow in both the endometrium and subendometrial region had significantly higher pregnancy rates than women without it: https://pubmed.ncbi.nlm.nih.gov/12137858/

Increased endometrial blood flow has been associated with improved ART outcomes and higher pregnancy rates: https://pmc.ncbi.nlm.nih.gov/articles/PMC11534959

By activating the deep abdominal and pelvic muscles, The Fertility Class™ supports healthy pelvic circulation and reproductive physiology.

Movement, Exercise, and Reproductive Function

A growing body of research links regular, moderate movement to improved menstrual regularity and ovulatory function, particularly in women with PCOS or ovulatory-related infertility.

Moderate physical activity has been associated with improved menstrual cycle regularity, increased ovulation, and higher chances of conception, especially in women with PCOS or anovulatory infertility: https://pmc.ncbi.nlm.nih.gov/articles/PMC5741916

A systematic review and meta-analysis found that maternal physical activity before IVF/ICSI cycles was associated with higher clinical pregnancy and live birth rates: https://pmc.ncbi.nlm.nih.gov/articles/PMC5803901

An important distinction: intensity matters. Research consistently shows that this benefit applies to moderate movement, not vigorous or high-intensity exercise, which has been associated with delayed time to pregnancy and ovulatory disruption in some studies.

Vigorous, high-frequency physical activity has been associated with increased subfertility and delayed time to pregnancy, in contrast to moderate activity: https://pmc.ncbi.nlm.nih.gov/articles/PMC7614776

This is precisely why The Fertility Class is built around targeted, low-impact movement sequences rather than cardio or high-intensity training, designed to support circulation and hormonal regulation without the ovulatory disruption associated with overtraining.

Nervous System Regulation and the Stress-Reproduction Connection

The nervous system and reproductive system are directly linked through the interaction between the hypothalamic-pituitary-adrenal (HPA) axis (the body's stress response system) and the hypothalamic-pituitary-gonadal (HPG) axis (the body's reproductive hormone system).

Chronic activation of the stress response has been shown to suppress GnRH secretion, the hormone that initiates the reproductive hormone cascade, through multiple neural and hormonal pathways: https://pmc.ncbi.nlm.nih.gov/articles/PMC6129417
Stress hormones have been shown to inhibit the release of gonadotropin-releasing hormone from the hypothalamus and luteinizing hormone from the pituitary, directly affecting ovarian hormone secretion: https://pmc.ncbi.nlm.nih.gov/articles/PMC4166402

The Fertility Class incorporates breathwork and nervous-system-regulating elements alongside movement, reflecting the physiological reality that reproductive hormone signaling and stress regulation are not separate systems.

Research Specific to the Aviva Method and Fertility-focused Movement

Three studies have evaluated the Aviva Method directly, summarized below with their actual findings and limitations.

Aviva Method and Menstrual Pain Relief

A 2024 peer-reviewed clinical trial tested a twice-weekly, 30-minute Aviva exercise intervention against a control group across two menstrual cycles in 78 women with primary dysmenorrhea. The intervention group showed a significant reduction in menstrual pain compared to the control group. No significant difference was found in the study's secondary measure, body awareness.

Aviva exercise was associated with significantly reduced menstrual pain compared to a control group in a prospective clinical trial: Kovács Z, Atombosiye E, Hegyi G, Szőke H. Medicina (Kaunas). 2024;60(1):184. doi:10.3390/medicina60010184 https://pmc.ncbi.nlm.nih.gov/articles/PMC10821191

Aviva Method and Uterine Artery Blood Flow

A related 2023 study by the same research group measured uterine artery blood flow via Doppler ultrasound immediately before and after a single 30-minute Aviva exercise session in 73 women with primary dysmenorrhea. The exercise group showed a significant increase in uterine artery pulsatility index immediately following exercise. The authors attribute this to normal exercise-induced circulatory redistribution, in which blood is temporarily shunted toward working skeletal muscle during physical exertion, a well-documented acute response to any exercise. This blood flow change was not correlated with the level of menstrual pain relief. The authors note their findings are preliminary, given the small sample, non-randomized design, and single-timepoint measurement, and call for larger, randomized studies.

Aviva Method in Poor-Responder IVF Patients

Distinct from the above, a pilot study has examined the Aviva Method directly in IVF patients classified as "poor responders", a group for whom no standard adjunct treatment currently exists. Initial data showed promising trends in oocyte and embryo quality among the small group of patients studied.

This is early-stage research. The initial findings have not yet been independently published or statistically validated, and the Aviva Method Center has since partnered with an IVF unit to conduct a larger, controlled clinical study testing the method's efficacy in this same patient population.

We believe in representing this work accurately: as a promising, active area of clinical investigation, not yet a proven outcome. We'll update this section as the controlled study progresses.

Bringing the Science Into Practice

Reproductive medicine research increasingly recognizes the importance of circulation, vascular health, nervous system regulation, and movement in fertility. The Fertility Class™ translates this scientific understanding into a structured, accessible movement practice designed to support pelvic circulation, hormonal signaling, and overall reproductive health.

Our guided classes provide women with a practical way to incorporate fertility-supportive movement into daily life.

Last updated: July 2026

Frequently Asked Questions

Please reach us at info@thefertilityclass.com if you cannot find an answer to your question.

Does exercise actually improve egg quality or fertility?

Research shows that moderate, not vigorous, physical activity is associated with improved menstrual regularity, increased ovulation, and better IVF outcomes, particularly for women with PCOS or ovulatory-related infertility. The mechanism is thought to run through improved pelvic blood flow and reduced stress-hormone suppression of reproductive hormones. Vigorous or high-intensity exercise has the opposite effect and has been linked to delayed time to pregnancy.

How does blood flow affect fertility?

Ovarian, uterine, and endometrial blood flow all play measurable roles in reproductive outcomes. Research using Doppler ultrasound has linked reduced blood flow in these areas to lower egg quality, poorer follicle maturation, lower implantation rates, and reduced IVF success. Improving circulation to these organs is one of the physiological targets of targeted movement practice.

Is The Fertility Class backed by clinical research?

A pilot study has examined the Aviva Method (the foundational method behind The Fertility Class) directly in poor-responder IVF patients, showing promising early trends in oocyte and embryo quality. This research is still early-stage: it has not yet been independently published or statistically validated, and a larger controlled clinical study is currently underway with an IVF unit. The Fertility Class is transparent that direct evidence is still developing, distinct from the broader, well-established research on movement, circulation, and the nervous system that underpins the method.

Can stress really affect fertility?

Yes. Chronic stress activates the hypothalamic-pituitary-adrenal (HPA) axis, which suppresses the release of GnRH and luteinizing hormone - hormones required to trigger ovulation. This is a well-documented neuroendocrine pathway, not a general wellness claim. It's why The Fertility Class combines movement with nervous-system-regulating elements like breathwork, and rhythmic movement, rather than treating movement and stress reduction as separate concerns.

What kind of exercise is best for fertility, if any?

The research points to gentle, targeted, moderate-intensity movement rather than intense cardio or high-impact training. This is the design basis for The Fertility Class's movement sequences, which focus on activating the pelvic and lower abdominal muscles to support circulation without the ovulatory disruption associated with overtraining.