NatPro is a study investigating two different approaches to the management of frozen embryo transfer during IVF treatment. The study will compare 'modified natural cycle' and 'programmed cycle' approaches to find out whether there are differences in how often women become pregnant and how often pregnant women experience preeclampsia.
The two most commonly used protocols for frozen embryo transfer are the natural (Nat) and the programmed (Pro) cycles. With the modified natural cycle, the dominant follicle (sac of fluid in the ovary which develops during ovulation) produces the hormones estradiol (estrogen) needed to thicken the uterine lining in preparation for embryo transfer. With the programmed cycle, the ovary does not produce estradiol and instead a woman is asked to take estradiol to thicken the uterine lining.
The full title of the study is Multi-center, parallel-group, randomized controlled trial of modified natural versus programmed cycles for frozen embryo transfers and their association with preeclampsia and live births.
Women may be eligible for this study if they:
- are 18-41 years old
- have frozen embryos created before the 40th birthday
- have regular menstrual cycles
- are willing to undergo elective single embryo transfer
- are willing to be assigned randomly to one of the two study treatment groups, 'modified natural' or 'programmed' cycles
There are strict laws governing the conduct of clinical studies. A process called informed consent ensures that participants know all the facts regarding the study prior to enrolling. Women who decide to participate will sign an informed consent document. This document is not a contract, and women may withdraw from the study at any time.
All participants will be monitored throughout the study, and a team will be on hand to answer all questions related to the study.
Women participating in the study will
- be assigned, randomly, to one of the two study treatment groups ('modified natural' or 'programmed' cycles)
- undergo single frozen embryo transfer
- undergo blood collection at some study visits
- complete questionnaires
- receive follow-up telephone calls
- have medical records reviewed at the end of study participation
Participating women will be compensated for time and effort. The costs of medications and embryo transfer remain the responsibility of the participating women and their insurance companies.
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