For medical or personal reasons, many women choose to delay childbirth. Cryopreservation allows women to freeze healthy eggs (occyte) for use in the future and women undergoing infertility treatments to freeze fertilized embryos for use in later treatments.
Cryopreservation of ova and embryos is recommended for women who want to delay childbirth or are undergoing medical treatment which may harm their fertility. Freezing embryos can shorten additional in-vitro fertilization cycles and help women to attempt multiple infertility treatments if in-vitro fertilization proves unsuccessful.
The procedure for cryopreservation of eggs involves retrieval of healthy ova. Egg harvesting is a common procedure performed on thousands of women daily. Ovulation is inducted and the ovaries are stimulated using fertility drugs to produce a large number of eggs. Infertility specialists can then select the healthiest eggs for cryopreservation after collection.
Egg collection (follicular aspiration) is performed on an out-patient basis. Surgeons remove the eggs using a special needle inserted into each follicle. The needle uses suction to draw the ova (unfertilized egg) from the follicle. The procedure will normally be conducted through the stomach wall. Eggs can be removed through the vagina or bladder if a laparoscopic approach is not suitable.
Eggs can be frozen as soon as they are collected. Using IVF techniques, eggs can be fertilized and frozen as embryos. Eggs and embryos are frozen in liquid nitrogen at a temperature of -196°C. To prevent ice damage the eggs are stored in individual straws.
When ready to be used, both frozen eggs and fertilized embryos can be inserted directly into the uterus using a transfer catheter.
Cryopreserved eggs are not fertilized. Once thawed, the eggs can be implanted into the uterus to allow natural conception. Thawed eggs can also be used in IVF treatments and transfered to the uterus once fertilized.
Cryopreserved embryos are pre-fertilized eggs. Freezing embryos can prove beneficial to men and women who are undergoing cancer treatments that could leave them infertile.
The IVF procedure of fertilization is completed before the embryos are frozen. To implant embryos the outer edge must be thawed to ensure the age of the embryo matches the age of the uterus lining. The embryos must be implanted at the same stage in the cycle as they were frozen.
The information on this site is not a substitute for diagnosis or treatment from a licensed medical practitioner. If you are experiencing a serious medical condition call your local emergency services or your doctor.