Embryology is the science of the development of an embryo from the fertilization of the ovum to the fetus stage. In humans, the term embryo refers to the ball of dividing cells from the moment the zygote implants itself in the uterus wall until the end of the eighth week after conception. Beyond the eighth week after conception (tenth week of pregnancy), the developing human is then called a fetus.
- Intracytoplasmic Sperm Injection (ICSI)
- Laser Selective Assisted Hatching
- Blastocyst Culture
- Pre-implantation Genetic Screening – PGS
- Family Balancing
- Embryo Cryopreservation
Intracytoplasmic Sperm Injection, most commonly known as ICS, is a procedure where a single sperm cell is selected and injected directly into each egg to fertilize it. ICSI can be used to overcome virtually any form of male factor infertility (low sperm count, motility, and/or morphology) as well as previous fertilization failure. It can also be used in cases where a previous vasectomy has been done, or when a vasectomy reversal has not been successful. ICSI is also the approach of choice in couples in which the male partner has suffered injury to the spinal chord (paralysis), which alters the neurologic mechanisms of erection, and/or affects the quality of the sperm.
Laser Selective Assisted hatching is a procedure that involves carefully making a hole in the outer layer of the embryo (zona pellucida). In order for an embryo to establish pregnancy it needs to “hatch” out of the zona pellucida to come in closer contact with the uterine lining. Quite often the zona pellucida might undergo changes that impede hatching of the embryo and as result pregnancy is not established; these changes might be due to factors such as in vitro culture conditions, advanced reproductive age, diminished egg quality (as in high FSH patients), or diminished embryo quality as seen when severe fragmentation of the cells in the embryo occurs. In these cases selective hatching has been shown to improve embryo implantation and viable pregnancy rates. The procedure is performed with a laser beam right before embryo transfer sometimes in combination with embryo de-fragmentation.
Blastocyst Culture, or extended culture, allows embryos to reach a more advanced stage of development in the laboratory prior to their transfer into the womb. Most human embryos develop relatively well up until 3 days in culture. At this point, normally developing embryos “turn on” their genomic machinery in order to use more complex nutrients. Blastocyst is the term to name the stage of development of an embryo by day 5. Blastocyst culture allows for further selecting embryos that are developing normally, in other words, its sort of survival of the fittest. Blastocyst culture might be beneficial in reducing multiple pregnancies as these more advanced embryos might have higher implantation potential than earlier stages, therefore, allowing for the transfer of lower numbers to the womb.
Pre-implantation Genetic screening, also known as “embryo screening”, is sophisticated technology that allows examination of embryos for anomalies of the chromosomes (numerical chromosomal anomalies also called “aneuploidies”, or structural chromosome anomalies also called translocations, and/or single gene defects). With PGD, embryo selection can be further determined prior to replacement into the uterine cavity. PGD may increase the chances of carrying a pregnancy to term. In 2002, CARE-LIFE, now Fertility & Genetics, became the first center in the South Florida area with a proven and successful PGD program. This technology can potentially enhance success rate for patients with advanced reproductive age, repeated miscarriages, history of prior failed IVF treatments, or with family history of certain genetic traits. When PGD is performed, one or two cells are gently removed from each embryo through an embryo biopsy. Analysis of chromosomes or a particular gene can be undertaken with the utilization of techniques such as F.I.S.H (Fluorescence In Situ Hybridization), or P.C.R. (Polymerase Chain Reaction).
Family balancing, also known as gender selection, is a term that refers to procedures which allow to conceive a child of the desired sex. Currently, the sex ratio can be shifted by pre-selecting the sperm to be used in the fertilization of the eggs. In addition, the sex make-up of the resulting embryo can then be confirmed by analysis of its sex chromosomes.
Cryopreservation of embryos is the process of preserving an embryo at sub-zero temperatures, generally at an embryogenesis stage, meaning from the point of fertilization to the blastocyst stage. The technique for embryo cryopreservation that we use at Fertility & Genetics is called vitrification and has the greatest success rates for thawing and implantation.
Embryo cryopreservation is an excellent option for patients who have remaining embryos after an IVF cycle. IVF patients who either fail to conceive with their first IVF attempt, or wish to have additional pregnancies in the future may become pregnant using these remaining cryopreserved embryos for Frozen Embryo Transfer (FET) cycles. Not only are FET cycles proving to be quite successful, but they allow a patient to achieve a pregnancy without repeating the stimulation and egg retrieval portion of an regular IVF cycle.