Infertility — A Comparison of Two Freezing Techniques
Citation(s)
Cohen J, Alikani M, Trowbridge J, Rosenwaks Z Implantation enhancement by selective assisted hatching using zona drilling of human embryos with poor prognosis. Hum Reprod. 1992 May;7(5):685-91.
Gook DA, Edgar DH Human oocyte cryopreservation. Hum Reprod Update. 2007 Nov-Dec;13(6):591-605. Epub 2007 Sep 10. Review.
Hershlag A, Paine T, Kvapil G, Feng H, Napolitano B In vitro fertilization-intracytoplasmic sperm injection split: an insemination method to prevent fertilization failure. Fertil Steril. 2002 Feb;77(2):229-32.
Wu J, Zhang L, Wang X In vitro maturation, fertilization and embryo development after ultrarapid freezing of immature human oocytes. Reproduction. 2001 Mar;121(3):389-93.
Yoon TK, Chung HM, Lim JM, Han SY, Ko JJ, Cha KY Pregnancy and delivery of healthy infants developed from vitrified oocytes in a stimulated in vitro fertilization-embryo transfer program. Fertil Steril. 2000 Jul;74(1):180-1.
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.