Stage of evidence
Large randomised trial of 4,376 women · Ovulatory participants
Mehmet Çolakoğlu website · Information article ·
Two preparation approaches
Natural-cycle preparation follows a person's ovulation; medication may sometimes trigger it. A programmed cycle prepares the uterine lining with oestrogen and progesterone. Choosing between them is a medical decision extending beyond calendar convenience. [1]
The main 2026 findings
Among 4,376 ovulatory women, healthy live-birth rates were similar: 41.6% versus 40.6%. Among clinical pregnancies, pre-eclampsia occurred in 2.9% with natural preparation and 4.6% with programmed preparation. Natural-cycle cancellations were more frequent. [1]
What this means for you
The findings support discussing preparation choices in comparable patients. They cannot automatically be applied to people who do not ovulate regularly or whose medical circumstances differ from the study. These percentages are not an individual pregnancy prediction.
Monitoring and everyday life
Share cycle regularity, previous preparation protocols and medication history. Ask how visits will be arranged, when the transfer date becomes clear and what happens if a cycle is cancelled. A natural approach still requires monitoring.
Questions for your clinician
Do I ovulate regularly? Why was my previous protocol chosen? Which health findings would change that choice? How will medication and monitoring be organised? Do not change an existing prescription on the basis of a research headline; review the plan with your team.
Frequently asked questions
Is a natural cycle always medication-free?
No. Ovulation triggering or progesterone support may be included in an individual plan.
Is programmed preparation wrong?
No. Selection depends on individual findings; this trial studied a particular group of ovulatory women.
Who do the pre-eclampsia percentages describe?
The 2.9% and 4.6% figures concern women who achieved clinical pregnancy, not everyone who began treatment.
Scientific sources
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