Assisted reproductive technology

Several aspects of reproductive technology are discussed. In tubal infertility, the choice between surgery or in vitro fertilization and embryo transfer (IVF-ET) is addressed. In cases with bilateral distal occlusion or otherwise bad prognosis, IVF is probably more successful and less expensive. IVF in unstimulated cycles has given promising results, with pregnancy rates comparable to the results from the National IVF-ET Registry. If these results can be confirmed by more studies they will probably have a great impact on the choice of treatment in tubal infertility. The results obtained with various transfer procedures in nontubal infertility have still to prove tubal transfer to be a more effective procedure than IVF. Finally, studies on microinsemination in male infertility or unexplained infertility with previous fertilization failure in IVF show promising results with the subzonal insemination and partial zona dissection procedures.     

Ovarian hyperstimulation for in vitro fertilization preceded by prolonged administration of a gonadotropin-releasing hormone agonist

In 51 patients, controlled ovarian hyperstimulation with clomiphene citrate (CC)/human menopausal gonadotropin (hMG), or hMG only, in 102 IVF cycles had previously resulted in a cancellation rate of 52% and no pregnancies. In 54 subsequent cycles the women were treated with prolonged administration of a gonadotropin-releasing hormone agonist (GnRHa) followed by hMG stimulation, the GnRHa group. The results were compared with the outcome of 47 cycles in patients who came for their first IVF attempt. In this group a CC/hMG regimen was used, the CC/hMG group. In the GnRHa group, 17 pregnancies were achieved, compared with 10 in the CC/hMG group. Only four cycles were cancelled in the GnRHa group, vis-à-vis 13 in the CC/hMG group, a significant difference. The study showed that prolonged use of GnRHa as a preparatory treatment is effective following previous failures of IVF.     

Preliminary experience with embryo intrafallopian transfer (EIFT)

Embryo intrafallopian transfer was accomplished in 10 patients. Approximately 48 hours after oocyte retrieval, the embryonic cleavage stage was evaluated and from two to six embryos were transferred to the fallopian tubes at the 2- to 8-cell stage using a laparoscopic technique. Five clinical pregnancies resulted; four patients have given birth to five healthy babies (one set of twins) and one had a miscarriage. These results are encouraging, and we believe that transfer of embryos to the fallopian tubes may be an alternative to GIFT or IVF treatment in selected groups of patients.     

Provocation testing of human sperm motility using energy substrates and activators of the cyclic nucleotide system. I. Establishment of conditions for response testing.

In order to establish a series of provocation tests to evaluate the integrity of the sperm cAMP pathway, manganese (Mn), 2-deoxyadenosine (DEA) (via adenylyl cyclase), and methyl-isobutyl-xanthine (MIX) (via phosphodiesterase) were tested for their capacity to activate the progressive motility of human sperm. Optimal responses were obtained using washed sperm previously incubated for 3 hours in substrate-poor medium (Hepes-buffered saline). Longer periods of incubation required the presence in addition of an energy substrate such as glucose. Exposure of sperm to seminal plasma for 24 hours prior to washing attenuated the responsiveness of the sperm to the different activators. Preliminary studies on the activation of the progressive motility of washed sperm from four normozoospermic men under fertility investigation, prepared under identical conditions, revealed differences in the pattern of response which may have pathophysiological relevance.     

Sperm penetration in capillary tubes with albumin-Ringer solutions

Linear penetration of sperm from 65 different semen samples was investigated in Ringer solutions containing 1%, 3%, and 6% bovine albumin and in cervical mucus by use of the capillary tube test. A high degree of correlation was observed between the penetration distances recorded in the Ringer-albumin solutions, particularly in the 3% and the 6% solutions, as compared with those observed in cervical mucus. The relative number of spermatozoa with abnormal configuration was found to be markedly lower in the upper segment of the tubes, indicating a relationship between propulsive motility and normal morphology.     

Morbid obesity treated by gastroplasty: radionuclide gastric emptying studies

Mechanisms by which gastroplasty for morbid obesity causes weight loss are poorly understood. We studied the role of altered gastric emptying in 50 patients before surgery, 1-4 weeks after surgery, and 2-24 months after surgery using technetium-99m pentetate in water for liquid meals and a Tc-99m styrene divinylbenzene copolymer resin in oatmeal for semisolid meals. We determined the emptying half-times of the stomach before and after surgery in the proximal and distal compartments. The proximal compartment emptied promptly in the early and late postoperative periods. The distal compartment emptied liquids at rates similar to those before surgery, while the late postoperative emptying of semisolids was significantly faster. The stoma connecting the two compartments thus permits rapid transit of liquids and semisolids without delay of distal compartment emptying. No correlation was seen between the emptying half-times or changes thereof and eventual weight loss. Delayed gastric emptying is therefore not the mechanism for satiety and weight loss after gastroplasty has been performed.     

Natural cycle IVF in unexplained, endometriosis-associated and tubal factor infertility.

BACKGROUND: To elucidate possible differences between unexplained and minimal peritoneal endometriosis-associated infertility, we studied their outcome in natural cycle IVF (NIVF). METHODS: A prospective cohort study was carried out on unexplained (33 couples), minimal peritoneal endometriosis-associated (30 couples) and tubal factor (24 couples) infertility in 223 NIVF cycles, using human chorionic gonadotrophin (HCG) for ovulation induction. RESULTS: During the first NIVF attempt, follicular and luteal phase oestradiol, FSH, LH and progesterone concentrations, as well as endometrial thickness and follicular diameter were similar among the three groups. Periovulatory follicular growth monitored from day of HCG administration to oocyte aspiration was significantly lowered in unexplained infertility compared with minimal endometriosis-associated and tubal factor infertility. The fertilization rate, clinical pregnancy rate per initiated cycle, per successful oocyte retrieval and per embryo transfer, in minimal endometriosis (80.0, 10.4, 16.0 and 23.5% respectively) were similar to that in tubal factor infertility patients (68.6, 5.8, 11.4 and 16.0%) but significantly higher (P < 0.05) than that of the unexplained infertility group (62.2, 2.6, 5.4 and 8.7%). CONCLUSIONS: The significant reduction in follicular periovulatory growth, fertilization and pregnancy rates in unexplained infertility compared with minimal peritoneal endometriosis patients may be explained by sub-optimal follicular development with possibly reduced oocyte quality, intrinsic embryo quality factors or by impaired implantation. From a clinical point of view, NIVF is less suited to unexplained infertility treatment, but might represent an interesting treatment option for minimal peritoneal endometriosis-associated infertility.