Related Experiment Video
Updated: Jul 11, 2026
06:40
Collection of Human Follicular Fluid, Follicle Somatic Cells, and Immature Oocytes from Individuals Undergoing In Vitro Fertilization
Published on: October 24, 2025
Natural cycle IVF: a question of semantics?
Simon John Philips1, Isaac Jacques Kadoch
1Ovo FertilityClinic Montréal Québec Canada. s.phillips@cliniqueovo.com
Reproductive Biomedicine Online
|September 15, 2007
Summary
Controlled natural cycle in vitro fertilization (IVF) offers a powerful infertility treatment option. This method uses minimal stimulation, proving effective and validating its use in assisted reproduction.
Area of Science:
- Reproductive Medicine
- Assisted Reproductive Technology
Background:
- Growing interest in less-stimulated or non-stimulated in vitro fertilization (IVF) protocols.
- Need for effective infertility treatments with reduced stimulation.
Purpose of the Study:
- To evaluate the efficacy and classification of a controlled natural cycle IVF protocol.
- To determine if medications used for cycle control induce stimulatory effects.
Main Methods:
- Implementation of a controlled natural cycle IVF protocol.
- Monitoring of cycles to assess medication effects.
Main Results:
- Extensive series of controlled natural cycles reported.
- No observed stimulatory effects from medications used for cycle control.
Conclusions:
- Controlled natural cycle IVF is a valid and effective assisted reproduction treatment.
- The protocol functions as a natural cycle despite medication use for control.
Related Concept Videos
01:24In Vitro Fertilization
In vitro fertilization (IVF) is a form of assisted reproductive technology where an egg is fertilized with sperm in a controlled laboratory environment before transferring the resulting embryo into the uterus. This process is designed to help individuals and couples experiencing difficulties conceiving.
The IVF process begins with ovarian stimulation, during which reproductive endocrinologists prescribe hormonal medications to stimulate the ovaries to produce multiple eggs instead of the single...
The IVF process begins with ovarian stimulation, during which reproductive endocrinologists prescribe hormonal medications to stimulate the ovaries to produce multiple eggs instead of the single...
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...
01:57Meiosis II
Meiosis II is the second and final stage of meiosis. It relies on the haploid cells produced during meiosis I, each of which contain only 23 chromosomes—one from each homologous initial pair. Importantly, each chromosome in these cells is composed of two joined copies, and when these cells enter meiosis II, the goal is to separate such sister chromatids using the same microtubule-based network employed in other division processes. The result of meiosis II is two haploid cells, each containing...
02:02Meiosis II
Meiosis II entails cell division and segregation of the sister chromatids, resulting in the production of four unique haploid gametes. The steps for meiosis II are similar to mitosis, except that meiosis II occurs in haploid cells, whereas mitosis occurs in diploid cells.
The timing and cell division patterns of meiosis differ between males and females. In male meiosis, the centrosomes are part of the formation of the meiotic spindle. However, in oocytes, including that of humans, Drosophila,...
The timing and cell division patterns of meiosis differ between males and females. In male meiosis, the centrosomes are part of the formation of the meiotic spindle. However, in oocytes, including that of humans, Drosophila,...
00:51Energy Budgets and Reproductive Strategies
Organisms must balance energy intake with the energy required for growth, maintenance, and reproduction. These trade-offs result in a variety of survivorship and reproductive strategies, including semelparity and iteroparity. Semelparous species reproduce only once in their lifetime, often investing most available resources into that single reproductive event. Iteroparous species, by contrast, reproduce multiple times over their lifetimes, typically allocating fewer resources to any single...
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...