R. Frydman

High pregnancy rate after early human embryo freezing

Human embryos produced by in vitro fertilization (IVF) were frozen with 1,2-propanediol as a cryoprotectant. Embryo survival after thawing was related to the presence of a nucleus in frozen cells and decreased with the increasing number of cells in the frozen embryo. None of five embryos frozen 3 or 4 days after IVF survived when thawed. Of 48 early embryos (35 patients) frozen 1 or 2 days after IVF, 42 (87.5%) were transferred in 32 patients. Ten pregnancies were initiated after frozen embryo transfer (ET). If we exclude the three infertile patients who had sexual intercourse in the fertile period, the pregnancy rate for each patient who had 1- or 2-day frozen embryo(s) was 22% (7 of 32). One of the pregnancies was obtained after ET of a 1-cell pronucleated frozen and thawed embryo. The rate of ongoing pregnancies after triple fresh ET was 23%. In patients having four embryos obtained in a single IVF cycle, the expected overall liveborn rate in an IVF-ET program including embryo cryopreservation could theoretically equal that of natural human fertility.

Evidence for an adverse effect of elevated serum estradiol concentrations on embryo implantation

Multiple follicular stimulation for IVF may be associated with greatly elevated serum E2 concentrations that are presumed to be antinidatory. This factor was analyzed in 825 consecutive embryo transfer cycles. The pregnancy rate decreased significantly after the transfer of one and two embryos in association with preovulatory E2 levels greater than the 90th percentile for the group (2320 pg/ml). The pregnancy rate did not vary with preovulatory E2 concentration following the transfer of three embryos. Highly significant correlations were noted between preovulatory E2 and early luteal phase concentrations of E2 and P. In a subgroup of 245 cycles, there were no significant relationships between implantation and early luteal phase levels of P or the ratio of E2/P. There was a small but nonsignificant tendency for the pregnancy rate to decrease in association with raised luteal E2. It is concluded that excessive E2 levels at the time of ovulation induction with hCG had an adverse effect on implantation when one or two embryos are transferred, but this may be overcome by the transfer of three embryos. The consequences for embryo transfer are discussed.

Does hygiene counseling have an impact on the rate of CMV primary infection during pregnancy?: Results of a 3-year prospective study in a French hospital.

BACKGROUND Cytomegalovirus (CMV) is the most frequent cause of congenital viral infection in developed countries. OBJECTIVES The objective of this study was to evaluate the impact of our prenatal CMV infection screening and counseling policy. STUDY DESIGN Since 2005, all pregnant women in our obstetric center have been informed about CMV infection, and if they agree, given a serological test at around 12 weeks of gestation (WG). If this first test is negative, the women and their partners are given hygiene counseling on how to prevent CMV infection, and a second test is performed at around 36 WG. RESULTS Among the 5312 women who had an unknown immune status, or were known to be seronegative when they had their first visit to our center for their current pregnancy, 97.4% agreed to CMV screening. Primary infection was detected in 11 women between 0 and 12 WG (0.42%), and seroconversion was diagnosed in five women between 12 and 36 WG (0.19%). CONCLUSIONS These results suggest that if clear information is given on CMV infection during pregnancy, the rate of seroconversion is lower following counseling than before counseling.

Task force report on the outcome of pregnancies and children conceived by in vitro fertilization (France: 1987 to 1989) *

OBJECTIVE To describe the outcome of pregnancies conceived by IVF and the follow-up of the children after a minimum of 1 year of life. DESIGN Survey of clinical pregnancies and follow-up of the children and comparison with national statistics. SETTINGS All clinical pregnancies from 11 French centers between January 1987 and June 1989. PATIENTS A total of 1,637 pregnancies resulting in 1,263 deliveries and 1,669 live-born or still-born children and 1,411 alive children after 1 year. MAIN OUTCOME MEASURES Gestational age of birth, birth weight, mortality rates, prevalence of congenital malformation, and prevalence of disorders during the follow-up of the children. RESULTS The preterm birth rate was 22.7% of all deliveries and 12.2% of single deliveries compared with 5.6% in France, and 34.7% of babies weighed < 2,500 g compared with 5.2% in France. The rate of perinatal, neonatal, and infant mortality were higher than the national average. The rate of malformation (2.86%) was comparable with national survey (2.08%). The health of children diseased during the whole follow-up was approximately 2%. CONCLUSION The health of children after 1 year of live is close normal.

Factors influencing the success rate of human embryo freezing in an in vitro fertilization and embryo transfer program

Certain factors influencing the success of embryo cryopreservation were analyzed from 124cycles of in vitro fertilization and embryo transfer (IVF-ET) program in which 193 1- or 2-day embryos were frozen and had already been thawed. There were 100 transfers of one or two surviving embryos from which 26 pregnancies were initiated. Several factors significantly influenced embryo survival after thawing. They were: (1) the developmental stage of frozen embryos; (2) the appearance of the embryo at the time of freezing; and (3) the mode of ovarian stimulation in the IVF cycle. The pregnancy rate after frozen-thawed embryo transfer was higher with 4-cell frozen embryos than with embryos at all other stages combined. There were also tendencies for the pregnancy rate to be higher if a spontaneous luteinizing hormone surge occurred in the transfer cycle or if the duration of embryo storage did not exceed 1 to 2months. The results obtained support a new policy in IVF-ET programs: it should be advantageous for the sterile couple if the immediate fresh embryo transfer is only performed with the categories of embryos that demonstrate a poor aptitude for survival following cryopreservation procedures.

Perinatal outcome of twin pregnancies obtained after in vitro fertilization : comparison with twin pregnancies obtained spontaneously or after ovarian stimulation

OBJECTIVE To compare the perinatal outcome of IVF-ET twin pregnancies to twin pregnancies conceived spontaneously or after ovarian stimulation without IVF-ET. DESIGN Retrospective analysis. PATIENTS Three groups of patients: those who conceived after IVF-ET (n = 72), after ovarian stimulation without IVF-ET (stimulation group, n = 82), or spontaneously (spontaneous group, n = 164). MAIN OUTCOME MEASURES High blood pressure, premature rupture of membrane, threatened premature labor, prematurity, low birth, small-for-gestational-age, cesarean section, and perinatal mortality. RESULTS Patients of the IVF-ET group were older and of higher socioeconomic class. We did not find any significant difference in the data analyzed, with the exception of the rate of emergency cesarean sections. In the IVF-ET group the prematurity rate (38.9%), small-for-gestational-age (18%), and perinatal mortality (3.47%) were not statistically different with respect to the stimulation group (45.1%, 23.2%, and 3.05%, respectively) or the spontaneous group (39.6%, 22.7%, and 4.27%, respectively). CONCLUSIONS Twin pregnancies account for 20% to 25% of all IVF-ET pregnancies. Their risk of adverse perinatal outcome does not seem to be increased when compared with spontaneous pregnancies or to pregnancies obtained after ovarian stimulation but without IVF-ET. However, a reduction in the proportion of multiple pregnancies, including twin gestation, should be a goal for IVF-ET teams.

Human and murine amniotic fluid c-Kit+Lin- cells display hematopoietic activity

We have isolated c-Kit(+)Lin(-) cells from both human and murine amniotic fluid (AF) and investigated their hematopoietic potential. In vitro, the c-Kit(+)Lin(-) population in both species displayed a multilineage hematopoietic potential, as demonstrated by the generation of erythroid, myeloid, and lymphoid cells. In vivo, cells belonging to all 3 hematopoietic lineages were found after primary and secondary transplantation of murine c-Kit(+)Lin(-) cells into immunocompromised hosts, thus demonstrating the ability of these cells to self-renew. Gene expression analysis of c-Kit(+) cells isolated from murine AF confirmed these results. The presence of cells with similar characteristics in the surrounding amnion indicates the possible origin of AF c-Kit(+)Lin(-) cells. This is the first report showing that cells isolated from the AF do have hematopoietic potential; our results support the idea that AF may be a new source of stem cells for therapeutic applications.

Interpretation of plasma luteinizing hormone assay for the collection of mature oocytes from women: definition of a luteinizing hormone surge-initiating rise.

Analysis of plasma luteinizing hormone (LH) assays (4 assays per day) permits the discernment of the onset of the physiologic effects of ovulatory release. This threshold value of LH plasma concentration (LH surge-initiating rise, LH SIR) is determined for each cycle in terms of the average baseline level of the previous day. The chronology of follicle and oocyte maturation after LH SIR is similar to that which follows chorionic gonadotropin (hCG) administration: none of the 20 patients, compared with 2 out of 10, had ovulated when laparoscopy was performed 30 to 35 hours and 36 to 38 hours after LH SIR time, respectively; 1 out of 3, 9 out of 14, and 5 out of 5 patients had an in vitro fertilized egg when oocytes were collected 30 to 32, 33 to 35, and 36 to 38 hours after LH SIR time, respectively. Thus the oocyte can be collected 34 to 35 hours after the LH SIR; at this point ovulation has not occurred and the oocyte is capable of being fertilized.

A 2-year study on cytomegalovirus infection during pregnancy in a French hospital.

Objectives  To evaluate the proportion of pregnant women agreeing to cytomegalovirus (CMV) serologic screening. To collect data on CMV infection during pregnancy.

Ultrasound study of the endometrium during in vitro fertilization cycles

Ultrasonography is a noninvasive technique for studying the characteristics of the endometrium. This method was used in our in vitro fertilization and embryo transfer program during the periovulatory period for determination of whether there exists a moment at which the uterine mucosa is most favorable for implantation of the ovum. The endometrial thickness was noted in the course of the periovulatory phase. No correlation was found between the ultrasound image and hormonal assays. The endometrial thickness was significantly greater (P less than 0.01) when the in vitro fertilization attempt resulted in a pregnancy, even when considering the number of embryos transferred. However, it was not possible to predict the probability of pregnancy with the use of endometrial thickness.