Prenatal exposure to household pets influences fetal immunoglobulin E production.

BACKGROUND: Early life pet exposure may protect against allergic sensitization during childhood. Few studies have evaluated the effect of prenatal pet exposure on potential neonatal markers of allergic risk. OBJECTIVE: The aim of this study was to investigate whether maternal exposure to pets affects cord blood IgE levels in a population-based, general risk, ethnically mixed birth cohort. METHODS: Pet keeping during pregnancy was ascertained from women residing in a defined area of Wayne County Michigan and recruited from five staff model obstetric clinics. Maternal venous blood was analysed for total and allergen-specific IgE along with cord blood total IgE from 1049 infants. RESULTS: Compared with infants from households with no cats or dogs kept indoors during pregnancy, infants whose homes had either cats or dogs had significantly reduced mean cord IgE levels [0.34 IU/mL (95% CI 0.30-0.38) vs. 0.24 IU/mL (0.20-0.27), P=0.025]. Similar effects were apparent in cat-only households [0.21 IU/mL (0.16-0.27), P=0.020] and dog-only households [0.24 IU/mL (0.19-0.29), P=0.045]. There was no effect on results when excluding mothers who reported avoiding pets due to allergy-related concerns. CONCLUSION: Mothers with either cats or dogs in their home during pregnancy deliver children with lower cord blood IgE levels compared with mothers who do not live with these pets, supporting the hypothesis that pet exposure influences immune development in a manner that is protective for atopy and is operant even before birth.

Full length cDNA structure and deduced amino acid sequence of human 3 beta-hydroxy-5-ene steroid dehydrogenase.

Polyclonal antibodies raised against 3 beta-hydroxysteroid dehydrogenase isolated from human placenta were used to screen a lambda gt11 expression cDNA library from the same tissue. The protein deduced from cDNA sequences contains 372 amino acids with a calculated mol wt of 42,216. Since 3 beta-hydroxysteroid dehydrogenase is the enzyme catalyzing the formation of all classes of hormonal steroids, the availability of the cDNA encoding this enzyme opens new possibilities for a detailed investigation of the factors regulating the expression and activity of this crucial enzyme in adrenal, gonadal as well as peripheral tissues.

Augmentation of the response of mouse uterine epithelial cells to estradiol by uterine stroma.

The effect of estrogen on the in vitro growth of mouse uterine epithelial cells was assessed. Epithelial cells from the immature mouse uterus were successfully cultivated in a 1:1 mixture of Dulbecco's Modified Eagle's Medium and Ham's F-12 supplemented with insulin (5 micrograms/ml), transferrin (10 micrograms/ml), hydrocortisone (10(-7) M), BSA (2 mg/ml), and fetuin (1 mg/ml). Addition of 17 beta-estradiol in the range of 1-100 nM did not significantly change the total DNA content of the epithelial cells. A binding component of [3H]estradiol by cultured uterine cells was shown to be specific, saturable, and of high affinity. Kd values for specific binding by epithelial and stromal cells were 1.0-1.7 x 10(-10) M. Maximal specific binding was 0.74 and 2.3 fmol/micrograms DNA for epithelial and stromal cells, respectively. Treatment of epithelial and stromal cells for 4 days with 10 nM estradiol led to a 2- to 6-fold increase in progesterone receptor concentration. Treatment of epithelial and stromal cells in mixed culture for 4 days with 10 nM estradiol resulted in a significant increase in total DNA. That epithelial-stromal contact was critical for estradiol stimulation was shown by the fact that if the cell types were separated into two compartments which still allowed free media mixing, total DNA was not enhanced by estradiol. These observations are organized into a model for mitogenic action of estradiol that seems to reconcile observed disparities in the action of the hormone in vivo and in vitro.

3 beta-hydroxysteroid dehydrogenase/isomerase in the fetal zone and neocortex of the human fetal adrenal gland.

The fetal zone of the human fetal adrenal (HFA) gland is established to have decreased 3 beta-hydroxysteroid dehydrogenase/delta 4-5 isomerase (3 beta HSD) activity compared to the neocortex or definitive zone. 3 beta HSD activity, however, can be induced in primary cell culture through treatment with ACTH. Therefore, the HFA with two distinct steroidogenic zones with differences in 3 beta HSD activity as well as the capacity to increase 3 beta HSD activity in response to ACTH provides an excellent model to study the regulation of this enzyme. The presence of 3 beta HSD in the fetal and neocortex zones of the HFA was examined using a polyclonal antibody raised against purified human placental microsomal 3 beta HSD. After homogenates of the fetal and neocortical zones of the HFA were electrophoresed on a sodium dodecyl sulfate-polyacrylamide gel and immunoblotted, the presence of the 3 beta HSD protein with a molecular size of 45 kDa could be demonstrated only in the neocortical zone. ACTH treatment (greater than 2 days) of fetal and neocortical zone explant cultures produced increases in cortisol secretion associated with the respective levels of immunodetectable 3 beta HSD protein. Cortisol and dehydroepiandrosterone sulfate were the respective principal steroid products of neocortical and fetal zone explants. After ACTH treatment, immunodetectable 3 beta HSD was induced to a greater magnitude in the neocortex. These findings provide evidence that the lack of 3 beta HSD activity in the fetal zone, previously considered to be the result of the presence of an endogenous inhibitor, is due to an absence of the protein in this portion of the gland. The lack or minimal expression of 3 beta HSD in the fetal zone of HFA may be due to the action (or lack thereof) of a tissue-specific factor regulating the synthesis of 3 beta HSD.

Pseudocorpus luteum insufficiency: a local defect of progesterone action on endometrial stroma.

A 23-yr-old woman whose initial complaint was infertility demonstrated glandular stromal dissociation with failure of the endometrial stroma to undergo pseudodecidualization in repeated endometrial biopsies taken late in the luteal phase. As the clinical presentation was consistent with the inadequate corpus luteum syndrome, hormone measurements were performed. The endometrial biopsy was abnormal during cycles in which the serum pattern of progesterone, estradiol, FSH, and LH was normal. Exogenous progesterone did not correct the abnormality. The patient, by in vitro studies, has approximately one half the number of high affinity progesterone-binding sites in the cytosol fraction of her endometrium compared to preparations from two normal control subjects. Since her cytosol-binding protein was qualitatively identical to two control subjects, the incomplete maturation of her endometrial stroma may represent an absence or reduced number of stromal cytosol receptors and/or a resistance to specific hormone action in an individual target tissue.

Creation of a fully active, cytosolic form of human type I 3beta-hydroxysteroid dehydrogenase/isomerase by the deletion of a membrane-spanning domain.

Human 3beta-hydroxysteroid dehydrogenase/steroid Delta(5)-Delta(4)-isomerase (3beta-HSD/isomerase) is a bifunctional, single enzyme protein that is membrane-bound in the endoplasmic reticulum (microsomes) and mitochondria of cells in the placenta (type I) and in the adrenals and gonads (type II). Two membrane-binding domains (residues 72-89 and 283-310) have been predicted by analyses of hydrophobicity in the type I and II isoenzymes (90% regional homology). These putative membrane domains were deleted in the cDNA by PCR-based mutagenesis, and the two mutant enzymes were expressed by baculovirus in insect Sf9 cells. Differential centrifugation of the Sf9 cell homogenate containing the 283-310 deletion mutant revealed that 94% of the 3beta-HSD and isomerase activities were in the cell cytosol, 6% of the activities were in the microsomes, and no activity was in the mitochondria. This is the opposite of the subcellular distribution of the wild-type enzyme with 94% of the activities in the microsomes and mitochondria and only 6% activity in the cytosol. The organelle distribution of the 72-89 deletion mutant lies between these two extremes with 72% of the enzyme activity in the cytosol and 28% in the microsomes/mitochondria. The integrity of the subcellular organelle preparations was confirmed by electron microscopy. Western immunoblots confirmed the presence of the 283-310 deletion mutant enzyme and the absence of the wild-type enzyme in the insect cell cytosol. The unpurified, cytosolic 383-310 deletion mutant exhibited 3beta-HSD (22 nmol/min per mg) and isomerase (33 nmol/min per mg) specific activities that were comparable with those of the membrane-bound, wild-type enzyme. The isomerase reaction of the cytosolic 283-311 deletion mutant requires activation by NADH just like the isomerase of the microsomal or mitochondrial wild-type enzyme. In contrast, the 72-89 deletion mutant had low 3beta-HSD and isomerase specific activities that were only 12% of the wild-type levels. This innovative study identifies the 283-310 region as the critical membrane domain of 3beta-HSD/isomerase that can be deleted without compromising enzyme function. The shorter 72-89 region is also a membrane domain, but deletion of this NH(2)-terminal region markedly diminishes the enzyme activities. Purification of the active, cytosolic 283-310 deletion mutant will produce a valuable tool for crystallographic studies that may ultimately determine the tertiary/quaternary structure of this key steroidogenic enzyme.

Analysis of coenzyme binding by human placental 3 beta-hydroxy-5-ene-steroid dehydrogenase and steroid 5----4-ene-isomerase using 5'-[p-(fluorosulfonyl)benzoyl]adenosine, an affinity labeling cofactor analog.

3 beta-Hydroxy-5-ene-steroid dehydrogenase and steroid 5----4-ene-isomerase copurify as a single, homogeneous protein from human placental microsomes. Affinity alkylation with 2 alpha-bromoacetoxyprogesterone suggests that the dehydrogenase and isomerase substrate steroids bind at different sites on the same protein. However, the coenzyme, NADH, completely abolishes the alkylation of both enzyme activities by the progestin analog [Thomas J .L., Myers R. P., Rosik L. O. and Strickler R. C., J. Steroid Biochem. 36 (1990) 117-123]. Unlike bacterial 3-keto-5-ene-steroid isomerase, the human isomerase reaction is stimulated by diphosphopyridine nucleotides (NADH, NAD+). The affinity labeling nucleotide analog, 5'-[p-(fluorosulfonyl)benzoyl]adenosine (FSA), inactivates the dehydrogenase and isomerase activities at similar rates in an irreversible manner which follows first order kinetics with respect to both time and alkylator concentration (0.2-0.6 mM). FSA is a cofactor site-directed reagent that binds with similar affinity as a competitive inhibitor of NAD+ reduction by dehydrogenase (Ki = 162 microM) or as a stimulator of isomerase (Km = 153 microM). Parallel plots derived from Kitz and Wilson analysis indicate that FSA inactivates the two enzyme activities with equal alkylation efficiency (k3/Ki = 1/slope = 0.51/mol-s for both). The 3 beta-hydroxysteroid substrate, pregnenolone, protects isomerase as well as dehydrogenase from inactivation by FSA. These observations are evidence for a single cofactor binding region which services both enzyme activities.

Physiological 3 beta-hydroxy-5-ene steroid substrates bind to 3 beta-hydroxysteroid dehydrogenase without the prior binding of cofactor.

3 beta-Hydroxy-delta 5-steroid dehydrogenase (3 beta-HSD)/steroid delta 5-4-isomerase catalyses the conversion of 3 beta-hydroxy-5-ene steroids (e.g. pregnenolone) to 3-oxo-4-ene-steroids (progesterone) in human placenta. Isotope exchange at equilibrium using NAD+/NADH and the 5 alpha-reduced steroids, 5 alpha-androstane-3 beta, 17 beta-diol and 5 alpha-androstan-17 beta-ol-3-one, determined a cofactor-first order of binding for these 3 beta-HSD substrates [1]. Exchange at equilibrium cannot be performed with 3 beta-hydroxy-5-ene steroids because 3 beta-HSD is not reversible with the 5-ene substrates. To compare their cofactor requirements for binding, 3 beta-hydroxy-5-ene and 3 beta-hydroxy-5 alpha-reduced steroids were tested as protectors against the inactivation of purified human placental 3 beta-HSD by 2 alpha-bromoacetoxyprogesterone (2 alpha-BAP) in the presence or absence of cofactor. In incubations without cofactor, pregnenolone or dehydroepiandrosterone dramatically slowed (protected) the rate of 3 beta-HSD inactivation by 2 alpha-BAP, an affinity alkylator that binds specifically at the 3 beta-HSD substrate site. In contrast, 5 alpha-androstan-3 alpha-ol-17-one, 5 alpha-androstane-3 beta, 17 beta-diol, or 11 alpha-acetoxy-5 alpha-pregnan-3,20-dione protected 3 beta-HSD from inactivation by 2 alpha-BAP only in the presence of NADH (0.3 microM) or NAD+ (10 microM). At these low concentrations, neither NADH nor NAD+ slowed the inactivation of 3 beta-HSD by 2 alpha-BAP in the absence of protector-steroid. Further, the 3-oxo-5 alpha-reduced alkylator, 11 alpha-bromoacetoxy-5 alpha-pregnan-3,20-dione (11 alpha-BA-5 alpha-P), did not inactivate 3 beta-HSD in a specific manner. After pre-incubation with NAD+ (10 microM), 11 alpha-BA-5 alpha-P inactivated 3 beta-HSD rapidly and specifically (t1/2 = 3.7 min). 11 alpha-Bromoacetoxyprogesterone inactivated 3 beta-HSD at the same rate (t1/2 = 5.0 min) in the presence or absence of NAD+. These affinity labelling studies confirm the cofactor-first binding order for 3 beta-hydroxy-5 alpha-reduced steroids, and conclusively show that the more important, physiological 3 beta-hydroxy-5-ene substrates bind to 3 beta-HSD without a cofactor requirement.

Site-directed mutagenesis identifies amino acid residues associated with the dehydrogenase and isomerase activities of human type I (placental) 3beta-hydroxysteroid dehydrogenase/isomerase.

3beta-hydroxysteroid dehydrogenase/steroid delta5-->4-isomerase (3beta-HSD/isomerase) was expressed by baculovirus in Spodoptera fungiperda (Sf9) insect cells from cDNA sequences encoding human wild-type I (placental) and the human type I mutants - H261R, Y253F and Y253,254F. Western blots of SDS-polyacrylamide gels showed that the baculovirus-infected Sf9 cells expressed the immunoreactive wild-type, H261R, Y253F or Y253,254F protein that co-migrated with purified placental 3beta-HSD/isomerase (monomeric Mr=42,000 Da). The wild-type, H261R and Y253F enzymes were each purified as a single, homogeneous protein from a suspension of the Sf9 cells (5.01). In kinetic studies with purified enzyme, the H261R mutant enzyme had no 3beta-HSD activity, whereas the Km and Vmax values of the isomerase substrate were similar to the values obtained with the wild-type and native enzymes. The Vmax (88 nmol/min/mg) for the conversion of 5-androstene-3,17-dione to androstenedione by the Y253F isomerase activity was 7.0-fold less than the mean Vmax (620 nmol/min/mg) measured for the isomerase activity of the wild-type and native placental enzymes. In microsomal preparations, isomerase activity was completely abolished in the Y253,254F mutant enzyme, but Y253,254F had 45% of the 3beta-HSD activity of the wild-type enzyme. In contrast, the purified Y253F, wild-type and native enzymes had similar Vmax values for substrate oxidation by the 3beta-HSD activity. The 3beta-HSD activities of the Y253F, Y253,254F and wild-type enzymes reduced NAD+ with similar kinetic values. Although NADH activated the isomerase activities of the H261R and wild-type enzymes with similar kinetics, the activation of the isomerase activity of H261R by NAD+ was dramatically decreased. Based on these kinetic measurements, His261 appears to be a critical amino acid residue for the 3beta-HSD activity, and Tyr253 or Tyr254 participates in the isomerase activity of human type I (placental) enzyme.

Over-expression of human type I (placental) 3 beta-hydroxy-5-ene-steroid dehydrogenase/isomerase in insect cells infected with recombinant baculovirus.

Human type I placental 3 beta-hydroxy-5-ene-steroid dehydrogenase/steroid 5-->4-ene-isomerase (3 beta-HSD/isomerase) synthesizes androstenedione from fetal dehydroepiandrosterone and progesterone from pregnenolone. The full length cDNA that encodes type I 3 beta-HSD/isomerase was inserted into the baculovirus, Autographa californica multiple nucleocapsid polyhedrosis virus, and expressed in Spodoptera fungiperda (Sf-9) insect cells. Western blots showed that the baculovirus-infected Sf-9 cells produced an immunoreactive protein that co-migrated with purified placental 3 beta-HSD/isomerase. Ultracentrifugation localized the expressed enzyme activities in all the membrane-associated organelles of the Sf-9 cell (nuclear, mitochondrial and microsomal). Kinetic studies showed that the expressed enzyme has 3 beta-HSD and isomerase activities. The Michaelis-Menton constant is very similar for the 3 beta-HSD substrate, 5 alpha-androstan-3 beta- ol-17-one, in the Sf-9 cell homogenate (Km = 17.9 microM) and placental microsomes (Km = 16.7 microM). The 3 beta-HSD activity (Vmax = 14.5 nmol/min/mg) is 1.6-fold higher in the Sf-9 cell homogenate compared to placental microsomes (Vmax = 9.1 nmol/min/mg). The Km values are almost identical for the isomerase substrate, 5-androstene-3,17-dione, in the Sf-9 cell homogenate (Km = 14.7 microM) and placental microsomes (Km = 14.4 microM). The specific isomerase activity is 1.5-fold higher in the Sf-9 cells (Vmax = 25.7 nmol/min/mg) relative to placenta (Vmax = 17.2 nmol/min/mg). These studies show that our recombinant baculovirus system over-expresses fully active enzyme that is kinetically identical to native 3 beta-HSD/isomerase in human placenta.

Adenomyosis: a neglected diagnosis.

Adenomyosis was present in 161 of 1619 consecutive hysterectomy specimens. Adenomyosis coexisted with other pelvic pathology in 97 women and was the only histologic finding in 64 women. Most patients were 35 to 50 years of age, parous, white, had not taken steroid hormones, had not had uterine surgery, and complained of abnormal uterine bleeding and/or pelvic pain. Adenomyosis was most associated with leiomyomata, endometrial hyperplasia and carcinoma, and endometriosis. The clinical signs of uterine enlargement and tenderness were rarely observed. The diagnosis was suspected preoperatively in 10% of women. At surgery, adenomyosis was not recognized in 65% of patients. Adenomyosis is a disease of unknown etiology whose uncharacteristic clinical profile and frequent association with more obvious pelvic pathology make it a neglected diagnosis.

Laparoscopy: is it replacing clinical acumen?

One thousand sixty-one laparoscopic procedures (80% for diagnostic indications and 20% for therapeutic indications) performed during a 51-month period were reviewed to assess the effectiveness of laparoscopy in improving clinical diagnosis and avoiding major surgery. The error in preoperative clinical assessment as compared to postlaparoscopic diagnosis was approximately 50%: disease was suspected more often than found. Pelvic inflammatory disease, endometriosis, and ovarian cyst were the entities most often confused. Tubal coagulation was the most common procedure performed for therapeutic reasons. The complication rate for all laparoscopies and associated procedures was 2.6%.

Infant survival following uterine rupture and complete abruptio placentae.

This report concerns a case of spontaneous rupture of the uterus through a previous cesarean scar with resulting complete abruptio placentae and extrusion of the fetus inside the intact membranes and the placenta into the peritoneal cavity. That the infant survived this dual insult is worthy of reporting.

Maternal hydrocephalus and pregnancy.

Women with cerebrospinal fluid (CSF) shunts for correction of hydrocephalus are rapidly joining the reproductive age population. These patients can have uncomplicated pregnancies and spontaneous vaginal deliveries. Careful attention to signs of CSF shunt malfunction, historical and ultrasonic screening for familial hydrocephalus, and antibiotic prophylaxis for delivery are recommended. Management of the first and second stages of labor is discussed. There is no apparent advantage to any particular technique for intrapartum analgesia.

Ovulation induction with low doses of clomiphene citrate.

Ovulation was induced with one-quarter tablet (12.5 mg) of clomiphene citrate given for five days to three oligoovulatory patients who had consistently formed functional ovarian cysts when given 50 and 25 mg of clomiphene citrate for five days. Two of the patients had polycystic ovary syndrome and the other had hypothalamic dysfunction associated with an eating disorder. On clomiphene citrate 12.5 mg for five days, one patient conceived, another produced inadequate cervical mucus but later conceived after in vitro fertilization and embryo transfer, and the third woman, who had concomitant fallopian tube disease, ovulated but has not conceived. Women oversensitive to clomiphene citrate can be effectively treated with very low doses of the drug. Perhaps other oligoovulatory patients may benefit from lower than currently recommended clomiphene citrate doses.

Raloxifene and estrogen effects on quality of life in healthy postmenopausal women: a placebo-controlled randomized trial.

OBJECTIVE: To assess the effects of raloxifene, estrogen, and placebo on quality of life in healthy, asymptomatic, postmenopausal women. METHODS: In a multicenter, double-blind, 12-month study, 398 women were assigned randomly to one of four groups: raloxifene HCl, 60 (n = 97) or 150 mg/day (n = 100); conjugated equine estrogens, 0. 625 mg/day (n = 96); or placebo (n = 105). The Women's Health Questionnaire, a validated quality-of-life instrument for perimenopausal and postmenopausal women, was administered at baseline and 3-month intervals. RESULTS: Overall, quality of life from baseline to end point was preserved equally in all treatment groups. Six domains (depressed mood, somatic symptoms, memory/concentration, sexual behavior, sleep problems, and perceived attractiveness) were unchanged in all groups. Three domains (menstrual symptoms, vasomotor symptoms, and anxiety/fears) were statistically significantly different among groups. Mean scores for menstrual symptoms significantly worsened and vasomotor symptoms significantly improved from baseline to end point in the estrogen group. Mean scores for vasomotor symptoms did not worsen at any point in the raloxifene 60 mg/day group. Mean anxiety/fears scores improved significantly during raloxifene 60 mg/day administration throughout treatment (P <.05), irrespective of previous hormone replacement therapy, baseline estradiol (E2) levels, or years postmenopause. CONCLUSION: Most quality-of-life domains were not affected by treatment with estrogen or raloxifene. Estrogen provided relief from vasomotor symptoms but caused menstrual symptoms. Raloxifene 60 mg/day improved anxiety levels in postmenopausal women.

Screening for factor V Leiden mutation before prescribing combination oral contraceptives.

OBJECTIVE: To evaluate the cost-effectiveness of screening for factor V Leiden mutation in women in the United States who use combination oral contraceptives. DESIGN: Cost-effectiveness analysis. SETTING: A national research reference laboratory, a university medical center, and an academic health center managed care organization. PATIENT(S): Women of reproductive age in the United States. INTERVENTION(S): Baseline risk estimates of venous thromboembolic disease in the general population and in carriers of factor V Leiden mutation were calculated using available data. MAIN OUTCOME MEASURE(S): The number of women who would require factor V Leiden testing and the cost of identifying this cohort to prevent one death caused by venous thromboembolic disease before prescribing combination oral contraceptives. RESULT(S): To prevent one venous thromboembolic death attributable to the use of oral contraceptives in women with factor V Leiden mutation, >92,000 carriers would need to be identified and stopped from using these pills. The estimated charge to prevent this one death would exceed $300 million. If the price of testing were discounted to 34.5% of current charges, the cost still would be between $105 million and $130 million. CONCLUSION(S): Screening for factor V Leiden mutation before prescribing combination oral contraceptives is not a cost-effective use of U.S. health care dollars. The best and most cost-effective screening tool we have is taking a thorough personal and family history related to venous thromboembolic events.

Ovarian stimulation with pure follicle-stimulating hormone/human menopausal gonadotropin and improved laparoscopic aspiration needles influence the success of an in vitro fertilization program.

The effect of a combined pure follicle-stimulating hormone/human menopausal gonadotropin (pFSH/hMG) ovarian stimulation regimen and modified, sharpened laparoscopic follicular aspiration needles on the number of oocytes retrieved and the oocyte/follicle ratio in 43 consecutive cycles of in vitro fertilization (IVF) were retrospectively compared with 99 consecutive preceeding cycles stimulated with hMG alone and captured with aspiration needles that had never been sharpened. A modified laparoscopic follicular aspiration needle is described. Purified FSH/hMG ovarian stimulation significantly improved the mean serum estradiol levels, number of preovulatory follicles, and, therefore, the total number of oocytes recovered per cycle. The mean ratios of oocytes recovered per preovulatory follicle documented on ultrasound, and per aspirated follicle, increased significantly using sharpened needles. Both modifications improved the success rate of our IVF program.

Laser vaporization of endometriosis in an infertile population: the role of complicating infertility factors.

One hundred twenty-two infertility patients with endometriosis were evaluated and treated using laparoscopy and laser vaporization to provide immediate elimination of all intraperitoneal disease. Ninety-five couples (77.8%) had one or more infertility factors (other than endometriosis) contributing to their infertility. Cervical factors, male factors, and luteal defects were associated with significantly decreased pregnancy rates, despite the use of laser vaporization. The number of contributing factors seemed to be unrelated to the likelihood of success in achieving pregnancy. The authors emphasize the need for total evaluation of other infertility factors in these patients. Such factors should be corrected prior to the use of laser laparoscopy, if possible, and dealt with on a continuing basis following use of this technique.

Ultrasound guidance for human embryo transfer.

Embryo transfer is facilitated with ultrasound guidance. The 16 ultrasound-guided transfers were rated easier, and there was less catheter distortion, in comparison with 12 transfers guided by "clinical feel." The benefits we ascribe to ultrasound guidance are as follows: (1) transfers can be done with the patient supine in the lithotomy position; (2) the catheter tip is accurately positioned in the fundus of the uterine cavity; (3) the ejection of the transfer bubble into the uterus and its persistence during catheter removal and documented; and (4) the continuance of the bubble is comforting to the patient. Greater experience is needed before the impact of ultrasound-guided transfer can be correlated with the rate of pregnancy continuance.