Anita Sjögren

Fertilization and pregnancy after intracytoplasmic microinjection of acrosomeless spermatozoa

Spermatozoa lacking acrosomes were injected into the cytoplasm of mature human oocytes. In two subsequent cycles, 12 of 28 (43%) oocytes were fertilized, and the ET of the second cycle resulted in a twin pregnancy. This report describes, to the best of our knowledge, the first case of successful fertilization and delivery after using acrosomeless spermatozoa. Our hope is that with increasing experience with microinjection, in the near future, this type of infertility will not remain a serious problem.

Reinsemination of one-day-old oocytes by use of intracytoplasmic sperm injection *

OBJECTIVE To evaluate the possible advantages of reinseminating oocytes by use of intracytoplasmic sperm injection (ICSI). DESIGN Clinical study. SETTING In vitro fertilization unit with research facilities. PATIENTS Fifty-seven couples who were part of our regular IVF program. INTERVENTIONS Nonfertilized oocytes from IVF cycles with no or very low fertilization were microinjected with spermatozoa approximately 25 hours after oocyte pick-up. MAIN OUTCOME MEASURES Fertilization and pregnancy rates. RESULTS A mean fertilization rate of 46.5% was obtained when reinseminating the oocytes on day 2 using the ICSI procedure. Of 57 cycles with completely or almost completely failed fertilization, 29 patients received ET after reinsemination by ICSI. Two of these transfers resulted in pregnancies (6.9% per ET) and two healthy babies were born. CONCLUSION Despite this relative success, considering both the extra work involved and the potential genetic risk, it is doubtful whether ICSI on day 2 should be recommended as a routine procedure. For training and research purposes, however, this approach can be of value.

Human blastocysts for the development of embryonic stem cells

Establishment of human embryonic stem cells (hES) from surplus human IVF embryos has been successful when both fresh and frozen-thawed cleavage stage embryos have been cultured to the blastocyst stage. This study reports the characteristics of the starting material, the blastocysts, for hES cell lines that were first derived at the University of Gothenburg, Sahlgrenska University Hospital in 1999. Twenty-two hES cell lines were derived by Cellartis AB from 114 blastocysts, giving an overall success rate of 19.3%. The blastocysts from which the hES cell lines were established were of varying morphological quality, both fresh and frozen-thawed. Two techniques of hES establishment were applied, i.e. direct application of the blastocysts on feeder cells or the standard immunosurgery method. It was further found that the efficiency by which frozen-thawed embryos gave rise to new hES cell lines was 3.7 times better than with fresh surplus embryos. These findings suggest that frozen-thawed embryos are superior to fresh surplus human embryos in hES cell establishment, which also avoids specific ethical problems associated with embryo donation in a fresh IVF cycle.

Preimplantation genetic diagnosis (PGD): The Gothenburg experience

Background. A program for preimplantation genetic diagnosis of pre‐embryos from patients with hereditary disorders was set up in our unit at Sahlgrenska University Hospital in 1994. The majority of the patients were carriers of X‐chromosome linked disorders; a few patients were translocation carriers. In this paper we describe our experiences of our first 36 cycles, 30 gender determinations and six analyses of embryos with possible translocations.

Oocyte maturation as regulated by follicular factors.

Follicular fluid (FFl), obtained from 24 women treated with clomiphene/hCG in an in vitro fertilization program, was characterized with respect to steroid hormone levels and oocyte maturation inhibitor (OMI) activity. Three FFl samples apparently were derived from cystic follicles and contained low steroid levels and no OMI activity in an in vitro rat oocyte assay. The remaining 21 follicles contained normal preovulatory steroid levels and mature and generally fertilizable oocytes. In 7 of these follicles the FFl (at 50% concentration) significantly inhibited rat oocyte meiosis, while 14 exerted no OMI activity. The results confirm earlier work on porcine and human FFl, suggesting that the putative OMI activity declines with follicular maturation.

Intrauterine capsules for incubation of gametes and subsequent release of embryos

In order to obtain incubation in uteri of spermatozoa, oocytes, and embryos, for treatment of patients referred for in vitro fertilization, a capsule was produced which could contain the human gametes and allow human fertilization and embryo growth after intrauterine introduction. Agar was chosen for capsule material and a mold was constructed for the production of capsules. The material was tested in vitro using mouse embryos and human oocytes and sperm. Intrauterine resolution was tested on mice and by insertion on 11 women. Empty capsules were inserted into the uterine cavity in 15 cycles the day after the luteinizing hormone peak and followed by daily ultrasound examinations. The resolution time was adjusted by changing the wall thickness of the capsules. The final type was dissolved after 3 to 4 days. No complications were observed and capsules could be inserted on all occasions. The major problem was expelling of capsules, which occurred in seven cycles. The problem seemed to be solved by the administration of indomethacin at the day of insertion.

Luteotropic and Luteolytic Factors Regulating Human Corpus Luteum Function a

Basic knowledge concerning factors regulating the life span and function of the corpus luteum (CL) has predominantly been gathered from experiments on various animals species. Species differences are considerable, however, and thus probably only experiments on primates can be directly translated to the human situation. The limited accessibility to well-defined human tissue material has made direct studies on human CL relatively scarce, and much of our knowledge is therefore based on extrapolations from measurements of steroid output from the CL in the ovarian vein or in the systemic circulation. The steroid levels in the venous effluent during the luteal phase are so high compared to those in the systemic circulation that a counter-current system carrying steroids between the ovarian vein and the ovarian artery was early postulated and has later been demonstrated both morphologically and functionally.’ It is likely also that other substances, such as prostaglandins (PGs), utilize this counter-current system to create an intraovarian environment of crucial importance for follicular development and CL function. Studies in the monkey’ and in the human3 support the theory that local ovarian factors may be as important in this connection as gonadotropins reaching the ovary through the systemic circulation. A normal follicle development thus seems to be essential or even a prerequisite for a normal CL function. This fact can easily be elucidated in the natural cycle, where the luteinized unruptured follicle (LUF) syndrome is a classical example. “Normal ” follicular development involves numerous events or factors such as ( a ) dynamic follicular growth, ( b ) selection of dominant follicle, ( c ) correct number of granulosa cells, ( d ) specific composition of follicular fluid, ( e ) capacity to rupture, cf) fertilizable oocyte, and Cg) intact CL function. In the early days of human IVF, it was claimed, for example by Edwards and coworkers,4 that interference with natural follicular development would inevitably cause problems in the luteal phase to such an extent that a normal CL function could not be secured. Other groups demonstrated, however, that superovulation induced by clomiphene’ and/or gonodotropins6 gave

Clinical experience in an in vitro fertilization and embryo replacement program of a new method for analysis of urinary estrogens

The clinical experience in an IVF/ER program of a newly developed commercial kit (Estradiol enzymatique; BioMerieux) to determine urinary estrogens enzymatically, is reported. The study included 157 cycles, and the main indication for treatment was infertility due to tubal factor. Follicular development was stimulated in most cases by a combination of clomiphene citrate, human menopausal gonadotropin and chorionic gonadotropin. In addition to the previously used method to monitor follicular growth, ultrasound, daily urinary estrogens (estradiol + estrone) levels were assayed. A correlation between the pattern of urinary estrogen and the clinical results was found. In cycles with continuously rising estrogen up to the time of hCG administration a higher rate of in vitro fertilization and clinical pregnancies were obtained as compared to cycles where urinary estrogen declined or levelled off. It is concluded that this enzymatic assay of urinary estrogens is a good alternative to increase the precision of follicle monitoring when radioimmunlogical assay of serum estradiol levels cannot be obtained on a daily routine basis.