Birth of a healthy baby after preimplantation genetic diagnosis in a carrier of mucopolysaccharidosis type II: The first case in Korea / 대한생식의학회지

Mucopolysaccharidosis type II (MPS II) is a rare X-linked recessive lysosomal storage disease caused by mutation of the iduronate-2-sulfatase gene. The mutation results in iduronate-2-sulfatase deficiency, which causes the progressive accumulation of heparan sulfate and dermatan sulfate in cellular lysosomes. The phenotype, age of onset, and symptoms of MPS II vary; accordingly, the disease can be classified into either the early-onset type or the late-onset type, depending on the age of onset and the severity of the symptoms. In patients with severe MPS II, symptoms typically first appear between 2 and 5 years of age. Patients with severe MPS II usually die in the second decade of life although some patients with less severe disease have survived into their fifth or sixth decade. Here, we report the establishment of a preimplantation genetic diagnosis (PGD) strategy using multiplex nested polymerase chain reaction, direct sequencing, and linkage analysis. Unaffected embryos were selected via the diagnosis of a single blastomere, and a healthy boy was delivered by a female carrier of MPS II. This is the first successful application of PGD in a patient with MPS II in Korea

Pre-implantation genetic diagnosis and pre-implantation genetic screening: two years experience at a single center

OBJECTIVE: Indications for preimplantation genetic diagnosis (PGD)/preimplantation genetic screening (PGS) cycles and clinical outcomes were evaluated at CHA Gangnam Medical Center. METHODS: This is retrospective cohort study. All patients (n=336) who went through in vitro fertilization (IVF)-PGD/PGS cycles (n=486) between January 2014 and December 2015 were included in Fertility Center of CHA Gangnam Medical Center. Patients underwent IVF-PGD/PGS with 24-chromosome screening. Patients with euploid embryos had transfer of one or 2 embryos in a fresh cycle with any subsequent frozen embryo transfer (ET) cycle. Compared implantation, clinical pregnancy, ongoing pregnancy, and early abortion rates were the main outcome measures. RESULTS: The most common indication for PGD/PGS was recurrent spontaneous abortion (n=160). The chromosome rearrangement cases (n=116) included 24 Robertsonian translocations, 60 reciprocal translocations, 3 inversions, 2 deletions, 4 additions, and 23 mosaicisms. PGS cases rather than the PGD cases showed higher implantation rates (26.4% vs. 20.3%), ongoing pregnancy rates (19.5% vs. 16.4%), and clinical pregnancy rates (28.6% vs. 23.3%). Implantation rates (30.3% vs. 23.7%), clinical pregnancy rates (39.2% vs. 25.2%), and ongoing pregnancy rates (25.7% vs. 17.5%) were significant higher in the blastocyst evaluation group than cleavage stage evaluation group. CONCLUSION: This was the largest study of PGD/PGS for 2 years at a single center in Korea. The pregnancy outcomes of PGD cases are slightly lower than PGS cases. It was confirmed again that success rate of PGD/PGS is higher if biopsy was done at blastocyst than cleavage stage.

Preimplantation genetic diagnosis

Preimplantation genetic diagnosis (PGD) is a technique to examine genetic disease or chromosome abnormalities in single cell biopsied from embryos before implantation to uterus. It allows achieving normal pregnancy by transfer of unaffected embryos. The main indications are single gene disorders and recurrent miscarriage related to chromosome aberration and it has advantages to avoid termination of pregnancy or miscarriages in couples with high risk. PGD is also widely applied for aneuploidy screening in assisted reproduction to improve the outcome in infertile patients such as advanced maternal age, although its efficacy still needs to be established. Furthermore, the application of PGD has expanded to other indications, such as late onset-diseases with genetic predisposition and human leukocyte antigen typing for stem cell transplantation. With the advances of molecular diagnostic technologies using single cells, such as fluorescent in situ hybridization, multiplex polymerase chain reaction, fluorescent polymerase chain reaction, linkage analysis, whole genome amplification, array comparative genomic hybridization (array comparative genomic hybridization), and next generation sequencing, PGD can provide more comprehensive and reliable diagnosis.

The first successful live birth following preimplantation genetic diagnosis using PCR for type 1 citrullinemia

Type 1 citrullinemia (CTLN1) is an autosomal recessive inherited metabolic disorder caused by anargininosuccinicnate synthetase deficiency. The patient was a 38-year-old Korean woman who is a carrier for CTLN1 and her first baby was diagnosed with CTLN1. Preimplantation genetic diagnosis (PGD) for CTLN1 in day 3 embryos using polymerase chain reaction was performed for live birth of healthy baby who is no affected with CTLN1. One unaffected blastocyst was transferred. This resulted in a clinical pregnancy and the live birth of healthy male twin. They were confirmed to be unaffected with CTNL1 by post natal diagnosis. This is the first case report of the use of PGD for CTNL1.

Preimplantation genetic diagnosis for Charcot-Marie-Tooth disease / 대한생식의학회지

OBJECTIVE: Preimplantation genetic diagnosis (PGD) is an assisted reproductive technique for couples carrying genetic risks. Charcot-Marie-Tooth (CMT) disease is the most common hereditary neuropathy, with a prevalence rate of 1/2,500. In this study, we report on our experience with PGD cycles performed for CMT types 1A and 2F. METHODS: Before clinical PGD, we assessed the amplification rate and allele drop-out (ADO) rate of multiplex fluorescent polymerase chain reaction (PCR) followed by fragment analysis or sequencing using single lymphocytes. We performed six cycles of PGD for CMT1A and one cycle for CMT2F. RESULTS: Two duplex and two triplex protocols were developed according to the available markers for each CMT1A couple. Depending on the PCR protocols, the amplification rates and ADO rates ranged from 90.0% to 98.3% and 0.0% to 11.1%, respectively. For CMT2F, the amplification rates and ADO rates were 93.3% and 4.8%, respectively. In case of CMT1A, 60 out of 63 embryos (95.2%) were diagnosed and 13 out of 21 unaffected embryos were transferred in five cycles. Two pregnancies were achieved and three babies were delivered without any complications. In the case of CMT2F, a total of eight embryos were analyzed and diagnosed. Seven embryos were diagnosed as unaffected and four embryos were transferred, resulting in a twin pregnancy. Two healthy babies were delivered. CONCLUSION: This is the first report of successful pregnancy and delivery after specific PGD for CMT disease in Korea. Our PGD procedure could provide healthy babies to couples with a high risk of transmitting genetic diseases.

Successful birth with preimplantation genetic diagnosis using single-cell allele-specific PCR and sequencing in a woman with hypochondroplasia due to FGFR3 mutation (c.1620C>A, p.N540K) / 대한생식의학회지

Hypochondroplasia (HCH) is an autosomal dominant inherited skeletal dysplasia, usually caused by a heterozygous mutation in the fibroblast growth factor receptor 3 gene (FGFR3). A 27-year-old HCH woman with a history of two consecutive abortions of HCH-affected fetuses visited our clinic for preimplantation genetic diagnosis (PGD). We confirmed the mutation in the proband (FGFR3:c.1620C>A, p.N540K), and established a nested allele-specific PCR and sequence analysis for PGD using single lymphocyte cells. We performed this molecular genetic analysis to detect the presence of mutation among 20 blastomeres from 18 different embryos, and selected 9 embryos with the wild-type sequence (FGFR3:c.1620C). A successful pregnancy was achieved through a frozen-thawed cycle and resulted in the full-term birth of a normal neonate. To the best of our knowledge, this is the first report of a successful pregnancy and birth using single-cell allele-specific PCR and sequencing for PGD in an HCH patient.

Outcomes of preimplantation genetic diagnosis using either zona drilling with acidified Tyrode's solution or partial zona dissection / 대한생식의학회지

OBJECTIVE: To review the outcomes of preimplantation genetic diagnosis (PGD) using zona drilling with acid Tyrode's solution (chemical zona pellucida drilling, chemical ZD) and those of partial zona dissection (PZD). METHODS: Clinical outcomes of seventy-one couples undergoing 85 PGD cycles from January 2005 to December 2010 were included. Blastocyst formation and the hatching rate, clinical pregnancy rate, ongoing pregnancy rate, implantation rate, and fetal gender ratio of the PZD and chemical ZD groups were compared. RESULTS: Application of PZD resulted in a significantly higher rate of clinical pregnancy (40.7% vs. 15.4%, p=0.022), ongoing pregnancy (35.6% vs. 11.5%, p=0.023), and implantation (18.1% vs. 5.7%, p=0.007) compared with chemical ZD. Among non-transferred embryos, the rate of blastocyst formation on day 5 (49.1% vs. 39.5%, p=0.016) and hatching on day 6 (47.2% vs. 26.5%, p<0.001) were also significantly higher in the PZD group. CONCLUSION: The mechanical zona dissection method showed better outcomes than chemical ZD in terms of the blastocyst development and pregnancy rate. In this study, the fact that chemical ZD was conducted in different period from mechanical method should be considered in interpreting the result.

Application of Hot Start PCR Method in PCR-based Preimplantation Genetic Diagnosis

PURPOSE: To determine a method to improve the efficacy and accuracy of preimplantation genetic diagnosis (PGD) - polymerase chain reaction (PCR), we compared hot start PCR and conventional multiplex nested PCR. MATERIALS AND METHODS: This study was performed with single lymphocyte isolated from whole blood samples that were obtained from two couples with osteogenesis imperfecta (OI). We proceeded with conventional multiplex nested PCR and hot start PCR in which essential reaction components were physically removed, and we compared the amplification rate, allele dropout rate and nonspecific products. Afterward, we used selective method for PGD. RESULTS: In the two couples, the respective amplification rate were 93.5% and 80.0% using conventional multiplex nested PCR and 95.5% and 92.0% using hot start PCR. The respective mean allele dropout rates for the two couples were 42.0% and 14.0% with conventional multiplex nested PCR and 36.0% and 6.0% with hot start PCR. CONCLUSION: The results demonstrate that the hot start PCR procedure provides higher amplification rates and lower allele dropout rate than the conventional method and that it decreased the nonspecific band in multiplex nested PCR. The hot start method is more efficient for analyzing a single blastomere in clinical PGD.

Does blastomere biopsy in preimplantation genetic diagnosis affect early serum beta-hCG levels? / 대한생식의학회지

OBJECTIVE: To determine whether the serum beta-human chorionic gonadotropin (hCG) profile following preimplantation genetic diagnosis (PGD) is lower than that of intracytoplasmic sperm injection (ICSI) cycles. METHODS: A total of 129 PGD cycles and 1,161 age-matched ICSI cycles, which resulted in pregnancy (serum beta-hCG> or =5 mIU/mL) on post-ovulation day (POD) 12 were included. We compared the mean serum beta-hCG levels on POD 12, 14, 21, and 28, doubling time of serum hCG, and created a cut-off value for predicting a singleton pregnancy in each group. RESULTS: The mean serum beta-hCG concentration of the PGD group was significantly lower than that of the control group on POD 12, 14, and 21. The doubling time of serum beta-hCG at each time interval showed no significant difference. The cut-off-value of serum beta-hCG for predicting a single viable pregnancy was 32.5 mIU/mL on POD 12 and 113.5 mIU/mL on POD 14 for the PGD group, which was lower than that for the control group. CONCLUSION: Blastomere biopsy may decrease the beta-hCG-producing activity of the trophoblasts, especially in early pregnancy. Setting a lower cut-off value of serum beta-hCG for predicting pregnancy outcomes in PGD may be needed.

Does blastomere biopsy in preimplantation genetic diagnosis affect early serum beta-hCG levels? / 대한생식의학회지

OBJECTIVE: To determine whether the serum beta-human chorionic gonadotropin (hCG) profile following preimplantation genetic diagnosis (PGD) is lower than that of intracytoplasmic sperm injection (ICSI) cycles. METHODS: A total of 129 PGD cycles and 1,161 age-matched ICSI cycles, which resulted in pregnancy (serum beta-hCG> or =5 mIU/mL) on post-ovulation day (POD) 12 were included. We compared the mean serum beta-hCG levels on POD 12, 14, 21, and 28, doubling time of serum hCG, and created a cut-off value for predicting a singleton pregnancy in each group. RESULTS: The mean serum beta-hCG concentration of the PGD group was significantly lower than that of the control group on POD 12, 14, and 21. The doubling time of serum beta-hCG at each time interval showed no significant difference. The cut-off-value of serum beta-hCG for predicting a single viable pregnancy was 32.5 mIU/mL on POD 12 and 113.5 mIU/mL on POD 14 for the PGD group, which was lower than that for the control group. CONCLUSION: Blastomere biopsy may decrease the beta-hCG-producing activity of the trophoblasts, especially in early pregnancy. Setting a lower cut-off value of serum beta-hCG for predicting pregnancy outcomes in PGD may be needed.

An update of preimplantation genetic diagnosis in gene diseases, chromosomal translocation, and aneuploidy screening / 대한생식의학회지

Preimplantation genetic diagnosis (PGD) is gradually widely used in prevention of gene diseases and chromosomal abnormalities. Much improvement has been achieved in biopsy technique and molecular diagnosis. Blastocyst biopsy can increase diagnostic accuracy and reduce allele dropout. It is cost-effective and currently plays an important role. Whole genome amplification permits subsequent individual detection of multiple gene loci and screening all 23 pairs of chromosomes. For PGD of chromosomal translocation, fluorescence in-situ hybridization (FISH) is traditionally used, but with technical difficulty. Array comparative genomic hybridization (CGH) can detect translocation and 23 pairs of chromosomes that may replace FISH. Single nucleotide polymorphisms array with haplotyping can further distinguish between normal chromosomes and balanced translocation. PGD may shorten time to conceive and reduce miscarriage for patients with chromosomal translocation. PGD has a potential value for mitochondrial diseases. Preimplantation genetic haplotyping has been applied for unknown mutation sites of single gene disease. Preimplantation genetic screening (PGS) using limited FISH probes in the cleavage-stage embryo did not increase live birth rates for patients with advanced maternal age, unexplained recurrent abortions, and repeated implantation failure. Polar body and blastocyst biopsy may circumvent the problem of mosaicism. PGS using blastocyst biopsy and array CGH is encouraging and merit further studies. Cryopreservation of biopsied blastocysts instead of fresh transfer permits sufficient time for transportation and genetic analysis. Cryopreservation of embryos may avoid ovarian hyperstimulation syndrome and possible suboptimal endometrium.

A Study of Guidelines for Genetic Counseling in Preimplantation Genetic Diagnosis (PGD)

PURPOSE: Preimplantation genetic diagnosis (PGD), also known as embryo screening, is a pre-pregnancy technique used to identify genetic defects in embryos created through in vitro fertilization. PGD is considered a means of prenatal diagnosis of genetic abnormalities. PGD is used when one or both genetic parents has a known genetic abnormality; testing is performed on an embryo to determine if it also carries the genetic abnormality. The main advantage of PGD is the avoidance of selective pregnancy termination as it imparts a high likelihood that the baby will be free of the disease under consideration. The application of PGD to genetic practices, reproductive medicine, and genetic counseling is becoming the key component of fertility practice because of the need to develop a custom PGD design for each couple. MATERIALS AND METHODS: In this study, a survey on the contents of genetic counseling in PGD was carried out via direct contact or e-mail with the patients and specialists who had experienced PGD during the three months from February to April 2010. RESULTS: A total of 91 persons including 60 patients, 49 of whom had a chromosomal disorder and 11 of whom had a single gene disorder, and 31 PGD specialists responded to the survey. Analysis of the survey results revealed that all respondents were well aware of the importance of genetic counseling in all steps of PGD including planning, operation, and follow-up. The patient group responded that the possibility of unexpected results (51.7%), genetic risk assessment and recurrence risk (46.7%), the reproduction options (46.7%), the procedure and limitation of PGD (43.3%) and the information of PGD technology (35.0%) should be included as a genetic counseling information. In detail, 51.7% of patients wanted to be counseled for the possibility of unexpected results and the recurrence risk, while 46.7% wanted to know their reproduction options (46.7%). Approximately 96.7% of specialists replied that a non-M.D. genetic counselor is necessary for effective and systematic genetic counseling in PGD because it is difficult for physicians to offer satisfying information to patients due to lack of counseling time and specific knowledge of the disorders. CONCLUSIONS: The information from the survey provides important insight into the overall present situation of genetic counseling for PGD in Korea. The survey results demonstrated that there is a general awareness that genetic counseling is essential for PGD, suggesting that appropriate genetic counseling may play a important role in the success of PGD. The establishment of genetic counseling guidelines for PGD may contribute to better planning and management strategies for PGD.

Preimplantation Genetic Diagnosis for Single Gene Disorders

Preimplantation genetic diagnosis (PGD) has become an assisted reproductive technique for couples who are at risk that enables them to have unaffected baby without facing the risk of pregnancy termination after invasive prenatal diagnosis. The molecular biology and technology for single-cell genetics has reached an extremely high level of accuracy, and has enabled the possibility of performing multiple diagnoses on one cell using whole genome amplification. These technological advances have contributed to the avoidance of misdiagnosis in PGD for single gene disorders. Polymerase chain reaction (PCR)-based PGD will lead to a significant increase in the number of disorders diagnosed and will find more widespread use, benefiting many more couples who are at risk of transmitting an inherited disease to their baby. In this review, we will focus on the molecular biological techniques that are currently in use in the most advanced centers for PGD for single gene disorders, including biopsy procedure, multiplex PCR and post-PCR diagnostic methods, and multiple displacement amplification (MDA) and the problems in the single cell genetic analysis.

Aspectos biomédicos de las inmunocalinas en la especie humana / Biomedical aspects of the immunocalins in human species

La familia de las lipocalinas está compuesta de varios miembros proteicos que son definidos,en general, por la actividad de unión de ligandos lipofílicos. Un subgrupo de lipocalinas, notablemente la glicoproteína ácida alfa 1, la-microglobulina alfa 1, la glicodelina, la lipocalina asociada a la gelatinasa del neutrófilo, la subunidad gamma del factor C8 del complemento, la prealbúmina lacrimal y la sintetasa de la prostaglandina D, ejercen significativas funciones inmunológicas, porque pueden tener actividad antiinflamatoria o antimicrobiana. Asimismo, muchos de los principales alergenos en los mamíferos son lipocalinas, lo que puede reflejar su conexión con el sistema inmune. Esta revisión resume estos hallazgos científicos y sus implicaciones en la salud humana.

Preimplantation Genetic Diagnosis for Aneuploidy Screening in Patients with Poor Reproductive Outcome / 대한불임학회지

OBJECTIVES: The risk of aneuploidies of embryos increases in advanced maternal age or parental karyotype abnormality and it results in poor reproductive outcomes such as recurrent spontaneous abortion (RSA) or repeated implantation failure (RIF). Preimplantation genetic diagnosis for aneuploidy screening (PGD-AS) can be applied for better ART outcome by selecting chromosomally normal embryos. The aim of this study is to evaluate the clinical outcome of PGD-AS and which group can get much benefit from PGD-AS among the patients expected to have poor reproductive outcome. METHODS: In 42 patients, 77 PGD cycles were performed for aneuploidy screening. Patients were allocated to 3 groups according to the indication of PGD-AS: group I-patients with old age (> or =37) and RIF more than 3 times (n=11, mean age=42.2 yrs.), group II-patients with RSA (> or = 3 times) associated with aneuploid pregnancy (n=19, mean age=38.9 yrs.), group III-parental sex chromosome abnormality or mosaicism (n=18, mean age=29.6 yrs.) including Turner syndrome, Klinefelter syndrome and 47,XYY. PGD was performed by using FISH for chromosome 13, 16, 18, 21, X and Y in group I and II, and chromosome X, Y and 18 (or 17) in group III. RESULTS: Blastomere biopsy was successful in 530 embryos and FISH efficiency was 92.3%. The proportions of transferable embryos in each group were 32.5+/-17.5%, 23.0+/-21.7% and 52.6+/-29.2% (mean +/- SD), respectively, showing higher normal rate in group III (group II vs. III, p<0.05). The numbers of transferred embryos in each group were 3.9+/-1.5, 1.9+/-1.1 and 3.1+/-1.4 (mean +/- SD), respectively. The clinical pregnancy rates per transfer was 0%, 30.0% and 20.0%, and it was significantly higher in group II (group I vs. group II, p<0.05). The overall pregnancy rate per transfer was 19.6% (10/51) and the spontaneous abortion rate was 20% (2/10) of which karyotypes were euploid. Nine healthy babies (one twin pregnancy) were born with normal karyotype confirmed on amniocentesis. CONCLUSION: Our data suggests that PGD-AS provides advantages in patients with RSA associated with aneuploidy or sex chromosome abnormality, decreasing abortion rate and increasing ongoing pregnancy rate. It is not likely to be beneficial in RIF group due to other detrimental factors involved in implantation.

The Ethical and Legal Considerations on Preimplantation Genetic Diagnosis and Prenatal Diagnosis / 대한산부인과학회지

OBJECTIVE: After 'Bioethics & biosafety act' has been enacted since 2005, Preimplantation genetic diagnosis (PGD) for embryo and Prenatal diagnosis (PD) for fetus are regulated by this law. This article will discuss the problem and revision of that law. METHODS: From the medical point of view, we consider the developmental stages of human embryo, genetic disease and PGD. According to the documentary records, we discuss the PGD allowance of European countries and USA and requisites for that allowance. We also discuss the PD in association with the 'Motherhood act' and a related judicial decision. RESULTS: On PGD, the attitude of quality of European countries is in the nature of variable spectrum and USA doesn't have explicit federal regulations. PGD permission is based on the individual institution and the genetic disease. The genetic conditions for legitimate abortion of 'Motherhood act are not included in Bioethics & biosafety act'. So The purpose and criteria of PD is now in a state of confusion. CONCLUSION: PGD should be regulated within the title of embryo in 'Bioethics & biosafety act' not within the title of genetic test. Each PGD should be permitted individually on the basis of each institution and genetic disease and then the criteria could be more broadened. The provision for PD should include the legitimate abortion conditions of 'Motherhood act'. To diagnose the sex linked genetic disease, the punishment for sex detection should be excepted to the 'Medicine act'.

Recent Trends in Preimplantation Genetic Diagnosis (PGD) / 대한산부인과학회지

Preimplantation genetic diagnosis (PGD) provides practical option to prevent the termination of pregnancy and miscarriage in couples with high risk of genetic disease or recurrent spontaneous abortion. In balanced chromosomal translocation, PGD can reduce the abortion rate and with PGD for aneuploidy screening, higher implantation rate and lower abortion rate can be obtained in patients with poor reproductive prognosis. Therefore PGD is widely used in ART for improving IVF efficiency. With technical development in single cell, such as FISH, PCR, CGH and microarray, the indications have expanded beyond the monogenic disease and chromosome aberration, as late-onset disease or HLA matching for stem cell donor.

Efficacy of Duplex-nested PCR and Fluorescent PCR in the Preimplantation Genetic Diagnosis for Duchenne Muscular Dystrophy / 대한불임학회지

OBJECTIVE: Preimplantation genetic diagnosis (PGD) is reserved for couples with a risk of transmitting a serious and incurable disease, and hence avoids the undesirable therapeutic abortion. In this study, we evaluated the efficacy of PGD for Duchenne muscular dystrophy (DMD) cases by the fluorescent PCR with polymorphic linked markers and the conventional duplex-nested PCR methods. METHODS: Biopsy of one or two blastomeres was done from the embryos fertilized by ICSI on the third day after fertilization. We performed two cases of PGD-DMD by the duplex-nested PCR for the causative mutation loci and the SRY gene on Y chromosome. The triplex fluorescent PCR for the mutation loci, the SRY gene and the polymorphic microsatellite marker on X chromosome was applied for two cases of PGD-DMD. RESULTS: By the duplex-nested PCR, successful diagnosis rate was 95.5% (21/22), but we could not discriminate the female embryos whether normal or carrier in this X-linked recessive disease. However, the triplex fluorescent PCR method showed 100% (27/27) of successful diagnosis rate, and all female embryos (n=17) were distinguished normal (n=10) from carrier (n=7) embryos. Unaffected and normal embryos were transferred into mother's uterus after diagnosis. A healthy normal male was achieved after PGD with the duplex-nested PCR method and a twin, a male and a female, were delivered with triplex fluorescent PCR method. The normality of dystrophin gene was confirmed by amniocentesis and postnatal genetic analysis in all offsprings. CONCLUSION: The fluorescent PCR with polymorphic marker might be useful in improving the specificity and reliability of PGD for single gene disorders.

Improvement of Pregnancy Rate in Preimplantation Genetic Diagnosis with FISH Procedure by the Laboratory Optimization and Experiences / 대한불임학회지

OBJECTIVES: This study was performed to evaluate the laboratory system for successful PGD using fluorescence in situ hybridization (FISH) and the clinical outcome of PGD cycles in five years experiences. METHODS: A total of 181 PGD-FISH cycles of 106 couples were performed, and diagnosed chromosome normality in the preimplantation embryos. The laboratory and clinical data were classified by the following optimization steps, and statistically analyzed. Phase I: Blastomere biopsy with two kinds of pipettes, removal of cytoplasmic proteins without treatment of pepsin and culture of biopsied embryos with single medium; Phase II: Blatomere biopsy with single pipette, removal of cytoplasmic proteins with pepsin and culture of biopsied embryos with single medium; Phase III: Blastomere biopsy with single pipette, removal of cytoplasmic proteins with pepsin and culture of biopsied embryos with sequential media. RESULTS: A total of 3,209 oocytes were collected, and 83.8% (2,212/2,640) of fertilization rate was obtained by ICSI procedure. The successful blastomere biopsies were accomplished in 98.6% (2,043/2,071) of embryos, and the successful diagnosis rate of FISH was 94.7% (1,935/ 2,043) of blastomeres from overall data. Embryo transfers with normal embryos were conducted in 93.9% (170/181) of started cycles. There was no difference in the successful rate of biopsy and diagnosis among Phase I, II and III. However, the pregnancy rate per embryo transfer of Phase III (38.8%, 26/67) was significantly (p<0.05) higher than those of Phase I (13.9%, 5/36) and Phase II (14.9%, 10/67). CONCLUSIONS: The laboratory optimization and experience for the PGD with FISH procedure can increase the pregnancy rate to 38.8% in the human IVF-ET program. Our facility of PGD with FISH provides the great possibility to get a normal pregnancy for the concerned couples by chromosomal aberrations.