In vitro fertilization does not increase the incidence of de novo copy number alterations in fetal and placental lineages.

Although chromosomal instability (CIN) is a common phenomenon in cleavage-stage embryogenesis following in vitro fertilization (IVF), its rate in naturally conceived human embryos is unknown. CIN leads to mosaic embryos that contain a combination of genetically normal and abnormal cells, and is significantly higher in in vitro-produced preimplantation embryos as compared to in vivo-conceived preimplantation embryos. Even though embryos with CIN-derived complex aneuploidies may arrest between the cleavage and blastocyst stages of embryogenesis, a high number of embryos containing abnormal cells can pass this strong selection barrier.

rs10732516 polymorphism at the locus associates with genotype-specific effects on placental DNA methylation and birth weight of newborns conceived by assisted reproductive technology.

Background: Assisted reproductive technology (ART) has been associated with low birth weight of fresh embryo transfer (FRESH) derived and increased birth weight of frozen embryo transfer (FET)-derived newborns. Owing to that, we focused on imprinted insulin-like growth factor 2 ()/ locus known to be important for normal growth. This locus is regulated by imprinting control region (ICR) with seven binding sites for the methylation-sensitive zinc finger regulatory protein (CTCF).

Short- and long-term health consequences and current satisfaction levels for altruistic anonymous, identity-release and known oocyte donors.

Study Question: What are the short- and long-term health consequences and current satisfaction of altruistic oocyte donors?

Summary Answer: Donating oocytes in the majority (>90%) of donation cycles is not associated with harmful long-term general or reproductive health effects.

What Is Known Already: Knowledge of long-term health effects of oocyte donation on donors is sparse and follow-up studies have usually been carried out on commercial donors. Thus far, no major long-term harmful effects have been demonstrated.

In-vitro maturation: its role in fertility treatment.

Purpose Of Review: In-vitro maturation of oocytes was primarily developed to make in-vitro fertilization safer and simpler for women with polycystic ovaries and high risk of ovarian hyperstimulation syndrome. In-vitro maturation has potentially many advantages over conventional in-vitro fertilization. A simple protocol with decreased or no hormonal stimulation before oocyte retrieval and thus lower cost of the treatment cycle are clear benefits.

In-vitro maturation of eggs: is it really useful?

In in-vitro maturation (IVM), immature oocytes are collected from small antral follicles and allowed to mature in the laboratory before routine in-vitro fertilization or micro-injection. The authors' experience in IVM is based on the treatment of two main groups of patients: women with polycystic ovaries and women with normal ovaries. Patients with polycystic ovarian syndrome have irregular, mostly anovulatory cycles and are at increased risk for ovarian hyperstimulation syndrome because of their higher sensitivity to gonadotropins.

Frozen embryo transfers: implications of clinical and embryological factors on the pregnancy outcome.

Background: Frozen embryo transfers are characterized by impaired pregnancy outcome and increased incidence of pregnancy loss as compared with fresh IVF/ICSI embryo transfers. In this study, we performed a retrospective analysis of clinical and embryological factors that potentially influence the outcome of frozen embryo transfer.

Methods: We reviewed the outcome of 1242 frozen embryo transfers with respect to the age of the woman, the method of fertilization, embryo quality before and after freezing and the number of embryos transferred.

Obstetric and perinatal outcome and preliminary results of development of children born after in vitro maturation of oocytes.

Background: Careful follow-up of children born after in vitro maturation (IVM) of human oocytes is essential because the technique is still very new.

Methods: Obstetric and perinatal data were collected from all deliveries after IVM treatment during 1999-2004. The growth and development of IVM children was assessed at 6, 12 and 24 months using Muenchener Funktionelle Entwicklungs Diagnostik and Bayley Scales of Infants.

Favourable pregnancy results with insemination of in vitro matured oocytes from unstimulated patients.

Background: The purpose has been to develop an in vitro oocyte maturation (IVM) method for a wide range of patients.

Methods: A total of 239 cycles with immature oocyte retrieval (IOC) were carried out without hormonal priming. Patients with regular cycles and normal or polycystic ovaries (PCO) and anovulatory cycles with PCOS were included.

Elevated incidence of chromosomally chaotic embryos among frozen-thawed preimplantation embryos.

Objective: The aim of the study was to evaluate the effect of cryopreservation on the formation of chromosomal abnormalities in human preimplantation embryos.

Study Design: The chromosomal constitutions of cleavage stage embryos (n = 61) were assessed using fluorescent in situ hybridisation (FISH) technique, applying probes for chromosomes 13, 16, 18, 21, X and Y. Study group embryos frozen at zygote or two-cell stage (n = 29) were cultured in vitro post-thawing until they reached four- to six-cell stage, after which their chromosomal constitutions were assessed.

Recombinant LH is equally effective as recombinant hCG in promoting oocyte maturation in a clinical in-vitro maturation programme: a randomized study.

Background: Fertilization treatment using oocytes matured in vitro from pre-ovulatory follicles has many potential applications. It minimizes the risk of severe ovarian hyperstimulation and is an alternative for women with polycystic ovary syndrome who may have problems regarding stimulation for IVF. In-vitro maturation (IVM) may prove important for subjects needing fertility preservation, and also provides information about the final stages of oocyte maturation.

Effect of developmental stage of embryo at freezing on pregnancy outcome of frozen-thawed embryo transfer.

Background: The study aim was to investigate the impact of the developmental stage of embryos on pregnancy outcome of frozen embryo transfer (FET).

Methods: The survival rates of embryos after thawing and pregnancy outcome following FET were compared retrospectively between three cryopreservation strategies utilizing either zygote, day 2 or day 3 embryo freezing.

Results: A total of 4006 embryos was analysed in 1657 thaw cycles.

Elective single embryo transfer yields good delivery rates in oocyte donation.

Background: High pregnancy rates have been noted after oocyte donation (OD). Multiple pregnancies should be avoided, because oocyte recipients have an increased risk of obstetric complications.

Methods: We analysed our OD results from 2000-2001 when elective single embryo transfer (eSET) was introduced as a recommended policy for all recipients if at least one good quality embryo was available.

Early cleavage predicts the viability of human embryos in elective single embryo transfer procedures.

Background: The reduction of multiple pregnancies by using elective single embryo transfers (eSET) requires critical and careful selection of the embryo for transfer. The current study was undertaken to assess whether early cleavage could be used as a marker of embryo competence in eSET procedures.

Methods: The study included analysis of 178 eSET procedures.

Influence of oocytes and spermatozoa on early embryonic development.

Objective: To evaluate the effect of oocytes and spermatozoa on early embryonic development.

Design: Retrospective study.

Setting: Infertility Clinic, the Family Federation of Finland.