The outcome from using cryopreserved embryos has uniformly been positive with no increase in birth defects or development abnormalities,[2] also between fresh versus frozen eggs used for intracytoplasmic sperm injection (ICSI).

[3] In fact, pregnancy rates are increased following FET, and perinatal outcomes are less affected, compared to embryo transfer in the same cycle as ovarian hyperstimulation was performed.

[7] The risk of having a large-for-gestational-age baby and higher birth rate, in addition to maternal hypertensive disorders of pregnancy may be increased using a "freeze all" strategy.

In a natural cycle the embryo transfer takes place in the luteal phase at a time where the lining is appropriately undeveloped in relation to the status of the present Luteinizing Hormone.

In order to optimise pregnancy rates, there is significant evidence that a morphological scoring system is the best strategy for the selection of embryos.

[17] Active efforts to develop a more accurate embryo selection analysis based on Artificial Intelligence and Deep Learning are underway.

This Deep Learning software substitutes manual classifications with a ranking system based on an individual embryo's predicted genetic status in a non-invasive fashion.

[20] The embryo transfer procedure starts by placing a speculum in the vagina to visualize the cervix, which is cleansed with saline solution or culture media.

[32] Evidence from randomized, controlled trials suggests that increasing the number of e-SET attempts (fresh and/or frozen) results in a cumulative live birth rate similar to that of DET.

Access to public funding for ART, availability of good cryopreservation facilities, effective education about the risks of multiple pregnancy, and legislation appear to be the most important factors for regional usage of single embryo transfer.

[34] There is considerable evidence that prolonges bed rest (more than 20 minutes) after embryo transfer is associated with reduced chances of clinical pregnancy.

[34] There may be little or no benefit in having a full bladder, removal of cervical mucus, or flushing of the endometrial or endocervical cavity at the time of embryo transfer.

[34] The use of Atosiban, G-CSF and hCG around the time of embryo transfer showed a trend towards increased clinical pregnancy rate.

[6] Seminal fluid contains several proteins that interact with epithelial cells of the cervix and uterus, inducing active gestational immune tolerance.

[39] In addition, a recent case-matched study comparing vaginal progesterone with PIO injections showed that live birth rates were nearly identical with both methods.

Embryo transfer may be used where a woman who has eggs but no uterus and wants to have a biological baby; she would require the help of a gestational carrier or surrogate to carry the pregnancy.

[43] This procedure was performed at the Harbor UCLA Medical Center [44] under the direction of Dr. John Buster and the University of California at Los Angeles School of Medicine.

Donor embryo transfer has given women a mechanism to become pregnant and give birth to a child that will contain their husband's genetic makeup.

Although donor embryo transfer as practiced today has evolved from the original non-surgical method, it now accounts for approximately 5% of in vitro fertilization recorded births.

At the time of this announcement the event was captured by major news carriers and fueled healthy debate and discussion on this practice which impacted the future of reproductive medicine by creating a platform for further advancements in woman's health.

[47] Recent systematic review showed that along with selection of embryo, the techniques followed during transfer procedure may result in successful pregnancy outcome.

Recent developments in the sexing of embryos before transfer and implanting has great potential in the dairy and other livestock industries.

For example, embryos of genetically modified strains that are difficult to breed or expensive to maintain may be stored frozen, and only thawed and implanted into a pseudopregnant dam when needed.

[55][56] The world's first live crossbred bovine calf produced under tropical conditions by Direct Transfer (DT) of embryo frozen in ethylene glycol freeze media was born on 23 June 1996.

Dr. Binoy Sebastian Vettical of Kerala Livestock Development Board Ltd has produced the embryo stored frozen in Ethylene Glycol freeze media by slow programmable freezing (SPF) technique and transferred directly to recipient cattle immediately after thawing the frozen straw in water for the birth of this calf.

In a study, in vivo produced crossbred bovine embryos stored frozen in ethylene glycol freeze media were transferred directly to recipients under tropical conditions and achieved a pregnancy rate of 50 percent.