A multicentre randomized controlled trial of oral misoprostol and i.m. syntometrine in the management of the third stage of labour

Postpartum haemorrhage accounts for nearly 28% of maternal mortality in developing countries. Syntometrine is an effective and commonly used oxytocic in preventing postpartum haemorrhage, but it requires a controlled storage environment and i.m. administration. Misoprostol is an orally active uterotonic agent. A total of 2058 patients having a singleton pregnancy, low risk for postpartum haemorrhage and vaginal delivery were randomized to receive either 1 ml syntometrine or 600 microgram misoprostol for the management of the third stage of labour. There were no significant differences between the two groups in the mean blood loss, the incidence of postpartum haemorrhage and the fall in haemoglobin concentration. The need for additional oxytocic injection was significantly higher in the misoprostol group [relative risk (RR) 1.62, 95% confidence interval (CI) 1.34-1.96], but that of manual removal of placenta was reduced (RR 0.29, 95% CI 0.09-0.87). Shivering and transient pyrexia were more common in the misoprostol group. Oral misoprostol might be used in the management of the third stage, especially in situations where the use of syntometrine is contraindicated and facilities for storage and parenteral administration of oxytocics are limited.     

Fertilization and early embryology: The effect of equilibration temperature and time on the outcome of ultrarapid freezing of 1-cell mouse embryos

Mouse 1-cell embryos were frozen ultrarapidly at a rate of 2500°C/minin solutions containing 0.25 M sucrose, 0.5% (w/v) bovine serumalbumin (BSA) and 3 or 4.5 M dimethyl sulphoxide (DMSO) or 3or 4.5 M 1, 2-propanediol (PROH) in HEPES-buffered modifiedEarle's medium. We investigated the effect of pre-freeze equilibrationfor 1, 3, 5 or 10 min at 22°C and for 1, 3, 5, 10, 15 or20 min at 4°C. After thawing in a 22°C water bath ata rate of 2500°C/min and dilution in 1 M sucrose in HEPES-bufferedmodified Earle's medium, embryos were cultured in vitro in bicarbonate-bufferedmodified Earle‘s medium with 0.5% (w/v) crystalline BSA.Embryo viability was expressed as the percentage of hatchingor hatched blastocysts resulting from the initial number offrozen-thawed 1-cell embryos. To determine the toxicity of thefreezing solutions, embryo viability was evaluated after equilibrationwithout freezing. Our results demonstrated that the concentration,the equilibration temperature and time are very important factorsin ultrarapid freezing of mouse 1-cell embryos. Optimal viabilitywas found when equilibration was done in 4.5 M DMSO for 3–5min at 22°C and in 4.5 M PROH for 3–5 min at 4°C.The results with regard to exposure to the freezing solutionsindicated that the loss of viability beyond an optimum is notdue solely to cryoprotectant toxicity, in particular not at4°C and not for DMSO. It is suggested that the temperatureand time of equilibration influence the degree of cryoprotectantpermeation and subsequent rehydration, which play a role indetermining freezing susceptibility in terms of ice formation.We conclude that both DMSO and, in contradiction to previousreports, PROH can be used perfectly adequately for ultrarapidfreezing on condition that concentration, and the temperatureand time of equilibration are controlled.     

Paternal effects acting during the first cell cycle of human preimplantation development after ICSI.

BACKGROUND: The ability of human embryos to undergo normal development has been shown previously to be subject to strong paternal (sperm-derived) effects. This study was undertaken to determine whether paternal influences on human embryo quality are detectable as early as the first cell cycle after fertilization. METHODS: The quality of zygotes and cleaving embryos resulting from sibling donor oocytes fertilized by sperm from different patients were compared in a donor oocyte-sharing programme. RESULTS: Fertilizations with sperm from certain individuals repeatedly resulted in the formation of high proportions of zygotes with abnormal pronuclear morphology that subsequently tended to cleave slowly and to show extensive fragmentation and blastomere irregularities. This phenomenon was observed with oocytes from two different donors for each of these individuals and contrasted with normal developmental performance of embryos resulting from sibling oocytes fertilized by sperm from other men with similar basic sperm characteristics. Fertilization rates were not related to these differences. CONCLUSIONS: These data point to a very early onset of paternal effects that condition human embryo development. These effects may be both of genetic (related to the minor gene activity of the male pronucleus) or epigenetic (related to the sperm-derived oocyte-activating factor or sperm centrosome) origin.     

Laser-assisted zona pellucida thinning prior to routine ICSI

BACKGROUND: In MII oocytes showing difficult oolemma breakage, ICSI can cause an increase in the degeneration rate. This may be overcome by laser-assisted ICSI using a 5-10 micro m opening in the zona pellucida for injection. However, such a small opening might impair the hatching process, especially if assisted hatching is applied in addition. In order to prevent this, the present study used routine injection through an area of zona pellucida in which laser zona thinning had been applied, providing for both a reduced mechanical stress to the oocyte and assisted hatching. METHODS: This prospective study involved 100 cycles with 1016 MII oocytes. Conventional ICSI (control group) was compared with a modified laser-assisted ICSI (study group) in sibling oocytes. In the latter group oocytes were injected through an extended area of zona thinning. RESULTS: Degeneration rate was significantly lower in the study group (P < 0.004). There were no differences in fertilization, or formation and quality of blastocysts. In the study group embryo quality on day 2 was significantly better (P = 0.004) and herniation of day 5 blastocysts was increased (P = 0.005). Rates of implantation and pregnancy were not affected. However, on day 3 laser-assisted ICSI proved beneficial (P = 0.038) in terms of clinical pregnancy rate. CONCLUSIONS: The new method combines a less invasive ICSI technique with assisted hatching. Our preliminary data indicate that in addition to an improved oocyte survival, this new approach increases the hatching rate in vitro, which may explain the increase in pregnancy rate, at least in day 3 transfers.     

Pregnancies following blastocyst stage transfer in PGD cycles at risk for beta-thalassaemic haemoglobinopathies.

BACKGROUND: Preimplantation genetic diagnosis (PGD) usually involves blastomere biopsy 3 days post-insemination (p.i.), followed by genetic analysis and transfer of unaffected embryos later on day 3 or 4. We evaluate a strategy involving embryo biopsy on day 3 p.i., genetic analysis on day 4 and, following culture in blastocyst sequential media, transfer of unaffected embryos on day 5 p.i. METHODS: PGD cycles were initiated in 15 couples at risk of transmitting beta-thalassaemia major. Oocyte retrieval and ICSI were performed according to standard protocols. Embryo culture used blastocyst sequential media. Embryos were biopsied on day 3 p.i. using acid Tyrode's for zona drilling, and the single blastomeres were genotyped by a protocol involving nested polymerase chain reaction and denaturing gradient gel electrophoresis analysis. RESULTS: Forty of 109 (37%) embryos biopsied on day 3 p.i. developed to blastocysts by day 5 p.i., with at least one blastocyst available for transfer in 12 cycles (80%). Genotype analysis characterized 51/109 (47%) embryos unaffected for beta-thalassaemia major, of which 28 were blastocysts. Transfer of 37 day 5 p.i. embryos (blastocysts and non blastocysts) initiated eight clinical pregnancies. Implantation rate per embryo transferred was 12/37 (32%). CONCLUSIONS: Embryo biopsy on day 3, followed by delayed transfer until day 5 p.i. offers a novel and effective strategy to overcome the time limit encountered when performing PGD, without compromising embryo implantation.     

未成熟树突状细胞诱导实验性自身免疫性重症肌无力耐受的试验研究

目的 探讨未成熟树突状细胞(iDC)对实验性自身免疫性重症肌无力(EAMG)的影响。方法 用小剂量粒-巨噬细胞集落刺激因子(GM-CSF)体外诱导骨髓前体细胞，获得的iDC用乙酰胆碱受体(ACAR)负载后皮下接种同基因大鼠，3周后通过体外试验观察脾细胞对AChR的增殖反应，同时用AChR和完全弗氏佐剂(CFA)免疫大鼠，观察免疫7周后MG相关指标的改变。结果 小剂量GMCSF诱导所获得的iDC与成熟DC(mDC)相比，其表面MHCⅡ和共刺激分子CD80、CD86的表达低，摄取dextran-FITC的能力强但刺激同种T细胞增殖的能力弱。接种iDC、mDC、AChR负载的mDC的大鼠和对照组一样，体外脾细胞对AChR的刺激均强烈增殖，用AChR和CFA免疫后，产生明显的MG症状，重复电刺激出现明显衰减，血清AChRAb滴度明显增高，神经肌肉接头呈现典型的MG样改变；而接种AChR负载的iDC的大鼠脾细胞对AChR的刺激呈现明显的增殖抑制但对卵清蛋白的刺激仍强烈增殖，MG相关指标均未见明显改变。结论 骨髓前体细胞经小剂量GM-CSF诱导产生了iDC，AChR负载的iDC可诱导EAMG耐受。     

Pregnancy outcome after blastocyst transfer as compared to early cleavage stage embryo transfer

BACKGROUND: Retrospective cohort study to evaluate differences in outcome when embryo transfer was performed either on day 2-3 (cleavage stage, CS-group) or on day 4-5 (blastocyst stage, BS-group). METHODS: A total of 1259 consecutive cycles yielding 500 live born babies performed at a single centre in Bregenz, Austria, were included. Main outcome measures were implantation and (multiple) pregnancy rates and neonatal outcome including birth defects. RESULTS: Total Pregnancy rate was 44% vs 28% (P < 0.001) and the total 'take home baby rate' was 37% vs 22% in the BS-group and the CS-group, respectively. Rate of multiple gestations (34% vs 17%, P = 0.001) was significantly higher among the BS-group, resulting in a higher rate of preterm deliveries < 36 weeks (26% vs 17%, P = 0.045). Female factor causing infertility (40% vs 21%, P < 0.001) was significantly higher among the BS-group. For the CS-group, rate of singleton pregnancies (83% vs 66%, P = 0.001) and idiopathic cause of infertility (34% vs 22%, P = 0.012) were significantly higher. No statistically significant differences were found in sex, Caesarean section rate, Apgar score and umbilical artery pH-values, total mean birth weight, admission rate to intensive care unit, days of hospitalization and number of minor and major birth defects. CONCLUSIONS: Our data suggest that blastocyst transfer may lead to a higher pregnancy rate with an overall better take-home baby rate (THBR) at the cost of higher rates of multiples and preterm deliveries.     

The formation of mesoderm and mesectoderm in 5- to 41-somite rat embryos cultured in vitro, using WGA-Au as a marker

Summary The formation of mesectodermal cells by the neural crest in 5- to 41-somite stage embryos was investigated experimentally in rat embryos cultured in vitro, using lectincoated colloidal gold as a probe. This method labelled all ectodermal cells, among them neural crest, surface ectodermal placodal and epiblastic (primitive streak) cells. The neural crest provides the mesodermal compartment of the entire head region with cells, including the primitive cranial ganglia and the branchial arches. In the head region migration of neural crest cells over a great distance (long-distance migration) was not observed. In the trunk region neural crest derived cells were mainly found to form the primitive spinal ganglia and the sympathetic trunk, once again without long-distance cell migration. Structures and tissues that supposedly were derived from the primitive streak were hardly labelled with colloidal gold. Surface ectodermal placodes were not only found at the expected sites (e.g. epibranchial placodes) but also in the ectoderm covering the transverse septum and lateral abdominal walls.