Controlled Ovarian Hyperstimulation (COH) is a fertility treatment process used to stimulate the ovaries to produce multiple eggs during a treatment cycle. COH is commonly used as part of IVF, IUI, egg freezing, and other assisted reproductive treatments to improve the chances of fertilisation and pregnancy.
During a natural menstrual cycle, the body usually matures one egg. With controlled ovarian hyperstimulation, fertility medication is used to encourage the development of multiple follicles and eggs within the ovaries.
At Umniya Fertility, COH forms part of the broader Umniya Method®, where fertility diagnostics, hormonal assessment, embryology, genetics, and personalised treatment planning are integrated into one coordinated fertility care pathway.
Controlled Ovarian Hyperstimulation is the process of using fertility medication to stimulate the ovaries during fertility treatment.
The goal is to increase the number of mature eggs available for:
Producing multiple eggs may improve the chances of fertilisation, embryo development, and successful pregnancy outcomes depending on the treatment plan.
COH protocols are carefully tailored according to ovarian reserve, hormone levels, age, reproductive history, and fertility diagnosis.
COH may be recommended for:
The treatment approach varies significantly between individuals. Some women require standard stimulation protocols, while others may benefit from lower stimulation or modified treatment plans depending on ovarian reserve and fertility goals.
COH involves using fertility medication to stimulate follicle development within the ovaries.
The process generally includes:
Once the follicles reach the appropriate stage of development:
At Umniya, ovarian stimulation protocols are personalised carefully to balance treatment response, egg quality, patient comfort, and safety throughout the cycle.
Treatment usually begins early in the menstrual cycle and involves regular monitoring appointments.
Patients may attend the clinic for:
The number of appointments varies depending on ovarian response and treatment type.
During stimulation, some women experience:
Once stimulation is complete, patients proceed either to egg collection, ovulation timing, or fertility treatment continuation depending on the treatment pathway.
At Umniya, treatment monitoring forms an important part of the fertility process, helping fertility specialists adjust medication safely and optimise ovarian response throughout the cycle.
Controlled ovarian hyperstimulation may help:
For patients pursuing IVF or ICSI, multiple eggs may provide more opportunities for embryo selection and future frozen embryo transfer cycles.
COH is widely used in modern fertility treatment and is generally considered safe when monitored carefully.
Potential risks and side effects may include:
At Umniya, monitoring protocols are designed to help minimise risks while supporting treatment outcomes.
Medication doses and treatment timing are adjusted carefully throughout stimulation based on hormone levels and follicle development.
In a natural menstrual cycle, the body usually develops one mature egg during ovulation.
With controlled ovarian hyperstimulation:
Natural cycle treatment may involve minimal or no stimulation medication, while COH is designed to maximise egg development for fertility procedures such as IVF, ICSI, or egg freezing.
The most appropriate approach depends on ovarian reserve, age, fertility diagnosis, and treatment goals.
At Umniya, ovarian stimulation protocols are integrated into a broader fertility care system focused on personalised reproductive planning and advanced fertility treatment.
The Umniya Method combines:
Throughout treatment, patients are supported by fertility specialists, embryologists, nurses, and care coordinators working together across every stage of the fertility journey.
COH usually takes around 8–14 days depending on ovarian response and the treatment protocol used.
Most patients attend several monitoring appointments during stimulation for ultrasound scans and hormone testing.
The number of eggs varies depending on age, ovarian reserve, hormone levels, and individual ovarian response.
COH may improve pregnancy chances by increasing the number of eggs available for fertilisation and embryo development during fertility treatment.
COH is commonly used before IVF and may also be used in selected IUI cycles depending on the treatment plan.
OHSS is a potential complication of ovarian stimulation in which the ovaries respond excessively to fertility medication. Most cases are mild, but monitoring is important to reduce risk.
Most patients tolerate fertility injections well. Mild discomfort or temporary bruising at the injection site can occur in some cases.