Two cases of dizygotic triplet pregnancy following conventional in vitro fertilization.

The mechanism of monozygotic multifetal pregnancy and its association with assisted reproductive technology are uncertain. This report presents two cases of dizygotic triplet pregnancy after the transfer of three embryos in utero. The incidence of monozygotic twinning following assisted conception procedures is higher than in the general population. Zonal manipulation may be a major factor in the increased incidence of monozygotic twinning. As both cases followed the conventional in vitro fertilization (IVF), the reason for these monozygotic twinnings might be because of the changes in the zona pellucida in in vitro conditions. In one case, fetuses developed into severe twin-to-twin transfusion syndrome (TTTS), resulting in one intrauterine fetal death at 26 weeks gestation. (Reprod Med Biol 2003; 2: 41-44).

Possible involvement of crosstalk cell-adhesion mechanism by endometrial CD26/dipeptidyl peptidase IV and embryonal fibronectin in human blastocyst implantation.

When human blastocysts hatch through the zona pellucida, gaining the ability to adhere to the endometrium, crosstalk between the embryo and the uterus may represent a successful outcome of their synchronized development and differentiation. CD26/dipeptidyl peptidase IV is known as a marker molecule of the implantation phase endometrium. To study the role of CD26 in implantation, 35 human hatched blastocysts were prepared by enzymatic treatment of expanded blastocysts that had been grown on schedule from frozen-thawed surplus embryos at the 2- or 4-cell stage. The blastocysts were placed on CD26-overexpressing or mock-transfected control monolayer cell cultures. The CD26-overexpression caused significantly higher blastocyst adhesion rate (53.3% versus 25.0%, P < 0.05) and significantly larger outgrowth area of trophectoderm (1.7-fold, P < 0.05). The second part of the present study was to show the expression of fibronectin, a CD26 ligand, in human preimplantation embryos, using the same donated resources. Fibronectin mRNA was detected by RT-PCR from the single hatched blastocyst (2/2) and from the single early blastocyst (3/6) but not from the single morula (0/5) samples. An indirect immunofluorescence technique verified the localization of fibronectin on the surface of the blastocyst. These results indicate that the adhesion mechanism by endometrial CD26 and embryonal fibronectin may be involved in human blastocyst implantation.

Dual renin-angiotensin blockade therapy in patients at high risk of early ovarian hyperstimulation syndrome receiving IVF and elective embryo cryopreservation: a case series.

BACKGROUND: Ovarian hyperstimulation syndrome (OHSS) is an important and dangerous aspect of assisted reproduction techniques. Although elective cryopreservation of all embryos can prevent pregnancy-induced late OHSS, it cannot prevent early OHSS, which is induced by hCG administration. METHODS: We undertook this trial to assess the efficacy with which the combined oral administration of angiotensin-converting enzyme inhibitor (ACEI) and angiotensin II receptor blocker (ARB) could prevent early OHSS in IVF patients at very high risk for this syndrome. Four women, who had serum estradiol concentration > or =8000 pg/ml on the day of hCG injection, were treated with the combination of the ACEI alacepril and the ARB candesartan cilexetil for 8 days starting the day after oocyte retrieval. Embryos were cryopreserved and embryo transfer was postponed until later cycles. RESULTS: Despite the extremely enlarged ovaries, no ascites was accumulated in any of the cases. Haematocrit (34.1 +/- 1.0) and serum albumin concentration (4.1 +/- 0.2 g/dl) were normal throughout the treatment period. These patients showed elevated plasma renin and angiotensin II concentration before the treatment. CONCLUSIONS: The dual renin-angiotensin blockade therapy used here would be worth exploring further in a study with more patients and a prospective, randomized design.