Biomedical subjects

S L Tan

Publications and source records attributed to S L Tan.

At least 109 records · Page 6Linked to original sources

PubMed1996

Transvaginal three-dimensional ultrasound: accuracy of follicular volume measurements.

OBJECTIVES: To evaluate the accuracy of three-dimensional (3-D) ultrasound (US) follicular volume measurements. DESIGN: Prospective clinical study. SETTING: A tertiary referral center for assisted reproduction. PATIENTS: Twenty-five patients undergoing ovarian stimulation for IVF-ET using the long protocol of GnRH agonist. INTERVENTION: Transvaginal two-dimensional (2-D) and 3-D ovarian scan performed immediately before US-directed follicle aspiration. MAIN OUTCOME MEASURES: The volume of follicular fluid aspirated was compared with the corresponding volume of the follicle measured by 3-D US and with the conventional 2-D US volume measurement calculated using the formula pi/6 (D1 x D2 x D3). Limits of agreement and 95% confidence intervals were calculated and systematic bias between the methods was analyzed. RESULTS: The limits of agreement between the volume of follicular aspirate and follicular volume determined by US were +0.96 to -0.43 mL for 3-D measurements and +3.47 to -2.42 mL for 2-D measurements. CONCLUSIONS: The true volume of ovarian follicles, within the clinically useful range for IVF-ET cycles, is measured more accurately by a 3-D US system than by 2-D US techniques.

Female↗

PubMed1996

Advances in the use of ultrasound in infertility management.

Over the past year a number of interesting studies using colour Doppler ultrasound have emerged in the field of infertility. Although they have increased our knowledge of physiological changes, prospective randomized studies are still awaited. The development of three-dimensional ultrasound systems is likely to provide improved spatial evaluation of pelvic organs and improve diagnosis of the polycystic ovary.

Blood Flow Velocity↗

PubMed1996

Behaviour therapy in psychiatric outpatients.

In a prospective study of fifty consecutive outpatients (30 men and 20 women) attending the Behaviour Therapy Clinic at a general hospital, the commonest conditions were obsessive compulsive disorders (n = 16), phobic disorders (n = 11) and generalised anxiety disorders (n = 9). Three-quarters of the referrals were from psychiatrists and family physicians. The patients received between 2 to 10 sessions of behaviour treatment; most had 4 to 6 sessions with a mean of 4.7, SD 1.82. The commonest behavioural techniques administered were exposure therapy with response prevention and relaxation therapy. Initially, treatment was therapist-aided, but subsequently self-help was encouraged with regular reviews of the patient's homework. After one month, 42 patients (84%) were assessed to have improved somewhat, with 20 (40%) showing moderate improvement. After three months, 41 (82%) continued to improve, with 33 (66%) showing moderate to great improvement. Nine patients were considered to have failed in therapy-six defaulted and three were non-responders. The reasons for defaulting treatment were unwillingness to bear with the discomfort involved in exposure therapy, lack of motivation or returning to own hometown in Malaysia. Sixteen patients (n = 32%) were treated solely with behavioural techniques while the rest had a combination of behaviour therapy and drugs, especially anxiolytics and antidepressants. However, at the end of treatment, the dosages of most medications were reduced or else discontinued completely.

Adolescent↗

PubMed1995

Vaginal color Doppler assessment of uterine artery impedance correlates with immunohistochemical markers of endometrial receptivity required for the implantation of an embryo.

OBJECTIVE: To investigate the correlation between uterine artery impedance with immunohistochemical histologic, and ultrasonographic markers of uterine receptivity. DESIGN: A prospective study of subfertile women undergoing a frozen embryo replacement cycle. SETTING: A tertiary infertility clinic. PATIENTS: The study was based on 86 patients who had failed to become pregnant during a standard IVF treatment cycle and who had at least two good quality embryos cryopreserved. INTERVENTIONS: All patients had pituitary desensitization with the GnRH analogue buserelin acetate, followed by E2 and P replacement therapy. Vaginal color Doppler images of both uterine arteries were obtained on days 7, 14, and 21 of the first (trial) cycle. On day 21, an endometrial biopsy was taken for dating a 24-kd protein, placental protein 14, and E2 receptor assessment. After a menstrual bleed had been induced, administration of estrogen and P was reinstituted and embryos transferred to the uterus on the 3rd or 4th day of P administration. MAIN OUTCOME MEASURES: The mean pulsatility index of the left and right uterine arteries, a semiquantitative score of endometrial 24-kd protein, PP14, and E2 receptor assessment, endometrial histologic dating, and pregnancy outcome. RESULTS: Nineteen of 76 patients who had a successful ET became pregnant. The pulsatility index on day 14 of both the trial and ET cycles was significantly lower in those who achieved pregnancy as compared with those who did not conceive: 2.65 (range 1.3 to 3.4) versus 3.85 (1.8 to 6.8) and 2.85 (1.4 to 3.6) versus 4.15 (2.1 to 6.8), respectively. There were significant correlations between pulsatility index and 24-kd protein, E2 receptor, and endometrial histology but not with PP14 and endometrial thickness. CONCLUSIONS: Uterine artery impedance has a significant correlation with biochemical markers of uterine receptivity and accurately predicts the probability of pregnancy in frozen embryo replacement cycles. It is a useful method for assessing uterine receptivity in assisted conception programs.

Adult↗

PubMed1995

Administration of progestogens to hasten pituitary desensitization after the use of gonadotropin-releasing hormone agonist in in vitro fertilization--a prospective randomized study.

OBJECTIVE: To assess the effect of administration of adjuvant IM progestogen to patients undergoing IVF who were not pituitary desensitized after 14 days of GnRH agonist (GnRH-a) administration. DESIGN: Prospective randomized study. SETTING: A tertiary referral center for assisted conception. PATIENTS: Forty-nine patients undergoing 51 IVF treatment cycles. INTERVENTION: Patients in whom the endometrial thickness was > 5 mm or who had an ovarian cyst > 15 mm after 14 days of GnRH-a administration were recruited if the serum E2 concentration was > 27.24 pg/mL (> 100 pmol/L). Patients in group 1 (n = 22) received a single IM injection of 100 mg P whereas patients in group 2 (n = 29) did not. Patients in both groups continued to receive SC GnRH-a 500 micrograms/d and had serum E2 levels measured every 3 days until the concentrations were < or = 100 pmol/L. MAIN OUTCOME MEASURES: The number of days of GnRH-a administration from recruitment until serum E2 concentration measured < or = 100 pmol/L, number of cycles with withdrawal bleeding, number of days from recruitment to withdrawal bleeding, total dose of hMG used, number of follicles > 14 mm, number of oocytes, number of embryos, and pregnancy rates per cycle commenced and per ET. RESULTS: There were no significant differences in all the above parameters except in the mean number of days from recruitment to onset of withdrawal bleeding, which were 5.33 +/- 0.7 (mean +/- SEM) and 8.62 +/- 1.26 days in groups 1 and 2, respectively. The pregnancy rate per ET was higher in group 1 (38.88%) when compared with group 2 (19.04%). However, this difference was not statistically significant. CONCLUSIONS: Adjuvant administration of a single IM injection of progestogen hastens the onset of withdrawal bleeding in patients who are not pituitary desensitized after 2 weeks of administration of SC GnRH-a. It does not appear to affect the length of time the serum E2 concentrations take to reach basal levels or to alter the ovarian responsiveness to exogenous gonadotropins.

Adult↗

PubMed1995

Circadian variation in uterine artery blood flow indices during the follicular phase of the menstrual cycle.

We investigated for the presence of circadian variation in uterine artery blood flow indices during the late follicular phase of the menstrual cycle. Twenty women with regular menstrual cycles underwent transvaginal color Doppler assessment of blood flow in the uterine arteries on two occasions precisely 12 h apart on the same day in the follicular phase. Ultrasound examinations were performed between 06.00 and 10.00 and repeated between 18.00 and 22.00. Indices of uterine artery blood flow included the pulsatility index (PI) and the time-averaged maximum velocity (TAMX). The changes in PI and TAMX were related to variations in serum concentrations of estradiol and luteinizing hormone (LH). We noted a significantly higher PI and lower TAMX in the evening compared to the morning values, p < 0.001 and p = 0.01, respectively. There was no significant change in estradiol or LH concentrations between morning and evening (p > 0.05). There appears to be a circadian rhythm in uterine artery blood flow occurring independently of these hormonal parameters. The circadian changes in PI and TAMX may be larger than the previously described effects of hormones on these parameters. The accurate interpretation of uterine artery blood flow indices should take these time-related fluctuations into account.

Adult↗

PubMed1995

Endometrial thickness, morphology, vascular penetration and velocimetry in predicting implantation in an in vitro fertilization program.

A total of 96 women undergoing in vitro fertilization (IVF) treatment were studied on the day of human chorionic gonadotropin (hCG) administration by transvaginal ultrasonography with color and pulsed Doppler ultrasound. We assessed endometrial thickness, endometrial morphology, presence or absence of subendometrial or intraendometrial color flow, intraendometrial vascular penetration and subendometrial blood flow velocimetry on the day of hCG administration and related the results to pregnancy rates. The overall pregnancy rate was 32.3% (31/96) and there was no significant difference between the pregnant and non-pregnant groups with regard to endometrial thickness, subendometrial peak systolic blood flow velocity (Vmax) or subendometrial pulsatility index (PI). The pregnancy rates based on endometrial morphology were not significantly different, being 17.6% (3/17), 33.3% (2/6) and 35.6% (26/73) for types A (hyperechoic), B (isoechoic) and C (triple-line) endometria, respectively. In eight (8.3%) patients, subendometrial color flow and intraendometrial vascularization were not detected. This absence of blood flow was associated with failure of implantation (p < 0.05). The pregnancy rates related to the zones of vascular penetration into the subendometrial and endometrial regions were: 26.7% (4/15) for Zone 1 (subendometrial zone), 36.4% (16/44) for Zone 2 (outer hyperechogenic zone) and 37.9% (11/29) for Zone 3 (inner hypoechogenic zone), and were not significantly different. Of cycles with type A endometrium, 23.5% (4/17) had absent subendometrial color, which was greater than the frequency of absent color in the type C endometrium (4.1%, p = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

Luteinized unruptured follicle: morphology, endocrine function and blood flow changes during the menstrual cycle.

A case of spontaneous luteinized unruptured follicle syndrome is presented with full documentation of hormonal, morphological and haemodynamic changes. Changes in uterine blood flow were also noted. Growth of the leading follicle was slow during the follicular phase of the cycle. After the luteinizing hormone (LH) surge, growth of the follicle was more rapid. Concurrently, the follicle developed internal echogenicity with ultrasonic evidence of separation of the granulosa cell layer. The follicle was no longer visible 144 and 132 h after the LH rise and peak respectively. There was no primary progesterone rise associated with either the LH rise or peak, but a secondary progesterone rise occurred 42 h after the onset of the LH surge. Peri-follicular blood flow velocity was detected for the first time on cycle day 5 and appeared to rise after the onset of the LH surge. Peri-follicular blood flow velocity appeared to reduce after the LH surge to values associated with the follicular phase. These observations are consistent with an association of a primary granulosa cell defect with luteinized unruptured follicle syndrome which would account for the initial slow follicular growth, absent primary progesterone rise and reduction in blood flow in the wall of the follicle after the LH surge.

Adult↗

PubMed1995

Intra-observer, interobserver, interultrasound transducer and intercycle variation in colour Doppler assessment of uterine artery impedance.

In this study we assessed the variability of measuring uterine artery pulsatility index by colour Doppler ultrasound using different ultrasound transducers (abdominal 3 MHz, abdominal 5 MHz, endovaginal 5 MHz with and without a full bladder). We then assessed the intra-observer coefficient of variation for the different transducers and interobserver variability for two observers using the endovaginal probe. The intercycle variability and effects of a full bladder on uterine artery blood flow were also assessed. The uterine vessels were most easily identified using the endovaginal transducer. The most reproducible results were obtained using the endovaginal probe. The coefficients of variation obtained for the vaginal route were intra-observer 4.1%, interobserver 11.8% and intercycle 16.5%. The blood flow indices were significantly different between the endovaginal and both transabdominal 5 and 3 MHz probes (P = 0.0027 and 0.0005 respectively). There was no significant effect of a full bladder on pulsatility index. This study suggests that transvaginal colour Doppler ultrasound is reproducible and the results obtained from clinical use would be reliable.

Abdomen↗

PubMed1995

Description of circadian rhythm in uterine artery blood flow during the peri-ovulatory period.

Uterine artery blood flow was assessed by transvaginal colour and pulsed Doppler ultrasound prospectively in six women during the peri-ovulatory period. All patients had regular ovulatory menstrual cycles and a mid-luteal serum progesterone consistent with spontaneous ovulation in the preceding cycle. Each patient underwent serial transvaginal ultrasound examination and Doppler assessment of blood flow in the uterine arteries. When the mean follicular diameter was > 16 mm or day -2 from the estimated day of ovulation was reached, patients were scanned at 6 hourly intervals at 0600, 1200, 1800 and 2400 h until follicular rupture. The pulsatility index (PI) and time averaged maximum velocity (TAMX) were calculated as Doppler indices of impedance to blood flow and velocity respectively. A venous blood sample was taken at each visit for subsequent hormonal analysis. The mean uterine artery PI showed a marked daily fluctuation with a nadir occurring most commonly at 0600 h. A comparison between the mean PI values at 0600 and 1800 h showed significantly lower results at 0600 h in both dominant (P < 0.05) and nondominant (P < 0.02) uterine arteries. Furthermore, mean uterine artery TAMX showed daily fluctuations with peak values most commonly occurring at 0600 h with the nadir occurring during the afternoon and late evening. There was no temporal relationship between the fluctuations in PI and changes in luteinizing hormone, follicle stimulating hormone, oestradiol or progesterone concentrations. These observations suggest that there is a circadian rhythm in uterine artery blood flow during the peri-ovulatory period which appears to be independent from the hormonal changes.

Adult↗

PubMed1995

Ovarian stromal blood flow in women with polycystic ovaries--a possible new marker for diagnosis?

Blood flow changes in the ovarian stroma of women embarking on in-vitro fertilization treatment were assessed on day 2 or 3 of the menstrual cycle using colour and pulsed Doppler ultrasound. Women were divided into three groups: group 1, 63 women with regular, ovulatory menstrual cycles and normal ovaries on ultrasound scan; group 2, 13 women similar to group 1 but with polycystic ovaries (PCO) on ultrasound scan; and group 3, 12 women with biochemical evidence of previous anovulatory cycles and/or oligomenorrhoea and/or elevated serum luteinizing hormone concentrations (> 10 IU/l) in the early follicular phase together with PCO on ultrasound scan. A subjective assessment of the intensity and quantity of coloured areas in the ovarian stroma appeared to be greater in both groups 2 and 3 compared with group 1. Mean (SEM) ovarian stromal peak systolic blood flow velocity (Vmax) was 16.88 (1.79) and 16.89 (2.36) cm/s in groups 2 and 3 respectively. These velocities were significantly greater than the mean (SEM) ovarian stromal Vmax of group 1; 8.74 (0.68) cm/s (P < 0.001). Mean (SEM) ovarian stromal time averaged maximum velocity (TAMX) was 10.55 (0.91) and 10.89 (1.80) cm/s in groups 2 and 3 respectively, both significantly greater than mean ovarian stromal TAMX of group 1, (P < 0.001). There was no significant difference in pulsatility index (PI) between the three groups. There thus appears to be significantly greater ovarian stromal blood flow velocity in women with polycystic ovaries as detected by colour and pulsed Doppler ultrasound. Increased ovarian stromal blood velocity may be a new parameter to assist in the ultrasound diagnosis of PCO.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

Diagnosis, prevention and management of ovarian hyperstimulation syndrome.

The overall incidence of clinically important (moderate to severe) OHSS ranges from 1% to 10% of IVF cycles, but only a small proportion (0.5% to 2%) of the cases are severe. In extreme but rare cases, secondary complications such as deep vein thrombosis, respiratory distress and acute hepato-renal failure may occur. The main risk factors are the presence of polycystic ovaries, high ovarian response to superovulation therapy, the use of hCG to trigger the ovulatory process or for luteal phase support, and the endogenous production of hCG by an early pregnancy. The pathogenesis of OHSS is unknown, although the predominant biochemical mediator is thought to be the renin-angiotensin system. Ovarian stimulation should always be carefully monitored to identify those women at risk. In IVF cycles, the hCG injection should be withheld if the risk is judged to be too great. Some women will benefit from a policy of proceeding to collect oocytes, but electively cryopreserving any resulting embryos, thus allowing the ovarian stimulation cycle not to be wasted. The administration of albumin at the time of oocyte collection will reduce the chance of severe OHSS occurring. If a decision is made to proceed with oocyte recovery and embryo transfer, it may be advisable to give 5000 IU of hCG, rather than 10,000 IU, as the ovulatory trigger. Progesterone, and not hCG, should be given in the luteal phase. Women developing mild or moderate OHSS should be kept under outpatient surveillance to detect the minority that may progress to severe OHSS. Those with severe OHSS should be hospitalised for fluid and electrolyte management. Paracentesis under ultrasound guidance is recommended where there are tense ascites, but further surgical intervention should rarely be undertaken and only when there is good clinical evidence of ovarian torsion or haemorrhage.

Female↗

PubMed1994

Hysterosalpingo contrast sonography (HyCoSy) and its future role within the investigation of infertility in Europe.

An important part of any protocol for investigation of the infertile couple is the assessment of Fallopian tube patency in the woman, as this can influence the future course of treatment. X-ray hysterosalpingography and laparoscopy and dye tubation are currently the main procedures for investigating tubal patency, but the recent development of hysterosalpingo contrast sonography (HyCoSy) may offer some benefits over these two methods. HyCoSy involves a transvaginal ultrasound investigation of the Fallopian tubes both before and after the injection of an echo-enhancing agent into the tubes via the uterine cavity. Evidence of tubal flow with B-mode scanning is indicative of tubal patency. Clinical data using the echo-enhancing agent, Echovist, in over 600 patients, in addition to technical aspects of the HyCoSy procedures are reviewed. The data presented indicate that the sensitivity and specificity of HyCoSy compare favorably with the current 'gold standard' techniques. HyCoSy is a safe, well-tolerated and relatively inexpensive procedure, which can be carried out in a short time during an outpatient consultation. Combining these undoubted benefits with the clinical results obtained to date would indicate that HyCoSy has the potential to be employed as a reliable and well-accepted procedure for assessing tubal patency as part of the investigation of infertility.

Journal Article↗

PubMed1994

Cumulative conception and live-birth rates after in vitro fertilization with and without the use of long, short, and ultrashort regimens of the gonadotropin-releasing hormone agonist buserelin.

OBJECTIVE: Our purpose was to compare cumulative conception and live-birth rates after in vitro fertilization with and without the use of the long, short, and ultrashort regimens of the gonadotropin-releasing hormone agonist buserelin. STUDY DESIGN: Life-table analysis of conception and live-birth rates in relation to ovarian stimulation regimen used in 2893 women who had one of five stimulation regimens exclusively throughout all treatment cycles, namely, human menopausal gonadotropin with or without clomiphene citrate; follicle-stimulating hormone with or without clomiphene citrate; and long, short, and ultrashort protocols of buserelin, plus follicle-stimulating hormone or human menopausal gonadotropin; and in an additional 347 women who had been administered both human menopausal gonadotropin and follicle-stimulating hormone with or without clomiphene citrate. RESULTS: The cumulative conception rate and cumulative live-birth rate were significantly higher in those women treated exclusively with the long buserelin regimen (59% and 55%, respectively, after three cycles) compared with those who only had human menopausal gonadotropin or follicle-stimulating hormone with or without clomiphene citrate (39% and 29%, respectively, after three cycles) (p = 0.001 and p = 0.0001) or compared with those who had only short or ultrashort buserelin regimens (22% and 17% after two cycles) (p = 0.0001 and p = 0.005). The pregnancy failure rate in patients on the long buserelin regimen was 22.4% (95% confidence interval 14.8% to 30.0%) compared with 33.3% (95% confidence interval 29.6% to 37.0%) in those who had human menopausal gonadotropin or follicle-stimulating hormone with or without clomiphene citrate (p = 0.03). When the probabilities of first conception and first live birth were examined by treatment regimen, after we allowed for the effects of age, cause of infertility, calendar year of treatment, and treatment cycle number (with a multiple logistic regression model), it was found that, relative to human menopausal gonadotropin or follicle-stimulating hormone with or without clomiphene citrate, the odds of conceiving with the long buserelin regimen was 1.63 (95% confidence interval 1.31 to 2.03) (p < 0.001) and the odds of a live birth was 1.97 (95% confidence interval 1.53 to 2.54) (p < 0.001). Similarly, relative to short or ultrashort buserelin the odds of conceiving with long bureselin was 1.88 (95% confidence interval 1.39 to 2.55) (p < 0.001) and the odds of a live birth was 1.79 (95% confidence interval 1.25 to 2.56) (p = 0.001). CONCLUSION: Pituitary desensitization with the long protocol of buserelin significantly increases the probabilities of conception and live birth after in vitro fertilization.

Adult↗

PubMed1994

Pregnancy and birth rates of live infants after in vitro fertilization in women with an without previous in vitro fertilization pregnancies: a study of eight thousand cycles at one center.

OBJECTIVE: Our aim was to compare the cumulative conception and live-birth rates after in vitro fertilization in women undergoing their first course of in vitro fertilization treatment with those in women undergoing their second course of treatment, having previously achieved an in vitro fertilization pregnancy. This study occurred in a tertiary referral-assisted conception unit. STUDY DESIGN: The cumulative conception rates obtained by life-table analysis in 4115 women having their first course of in vitro fertilization therapy (7327 treatment cycles leading to 1123 pregnancies) were compared by means of the log-rank test with those of 331 women in their second course of treatment, having previously achieved an in vitro fertilization pregnancy (561 treatment cycles leading to 138 second in vitro fertilization pregnancies). Similarly, the cumulative live birth rates of 3824 women in their first course of treatment (7136 treatment cycles leading to 732 live births) were compared with those of 105 women in their second course of treatment, having previously achieved an in vitro fertilization live birth (205 treatment cycles leading to 33 second in vitro fertilization live births). RESULTS: The cumulative conception rates and cumulative live birth rates were significantly higher in women having their second course of in vitro fertilization treatment than in those having their first course (cumulative conception rate: p = 0.0001; cumulative live birth rate, p = 0.007). After five cycles of in vitro fertilization, the cumulative conception rates and cumulative live birth rates were 49.8% (95% confidence interval, 46.3% to 53.5%) and 39.0% (95% confidence interval, 35.4% to 42.9%), respectively, in those having their first course of treatment compared with 69.9% (95% confidence interval, 57.6% to 81.3%) and 68.6% (95% confidence interval, 46.1% to 88.5%), respectively, in those having their second course. The estimated median numbers of cycles taken to achieve a pregnancy and live birth (assuming all women could potentially undergo the same number of cycles) were six and eight, respectively, in the first course of treatment compared with only three and five in the second course. CONCLUSION: Women who have achieved a previous in vitro fertilization pregnancy have significantly higher cumulative conception rate and cumulative live birth rates compared with those of women having their first course of treatment.

Adult↗

PubMed1994

Midluteal-phase vaginal color Doppler assessment of uterine artery impedance in a subfertile population.

OBJECTIVE: To compare the midluteal uterine artery impedance to blood flow as measured by the pulsatility index in women with different causes of infertility with that of women with normal fertility and to correlate this with endometrial thickness. DESIGN: A prospective study of normal women undergoing insemination with donor semen and subfertile women with tubal damage, endometriosis, premature ovarian failure, anovulation, or unexplained infertility. SETTING: A tertiary infertility center. PATIENTS: One-hundred sixty-one women (25 to 40 years of age) who were attending the clinic for subfertility treatment and 23 normal women who were having artificial insemination with donor sperm because their partners were azoospermic. INTERVENTIONS: All women were examined by transvaginal ultrasonography, with color flow imaging and blood flow analysis, on day 21 of an unstimulated ovarian cycle. MAIN OUTCOME MEASURES: The mean pulsatility index of the left and right uterine arteries and the endometrial thickness. RESULTS: The patients were grouped according to the causes of infertility and compared with normal women. There were 23 women in the normal group (median pulsatility index, 1.91; range, 0.84 to 2.95), 35 with unexplained infertility (median pulsatility index, 2.45; range, 1.0 to 7.0), 91 with tubal damage (median pulsatility index, 2.65; range, 1.25 to 8.0), 8 with endometriosis (median pulsatility index, 2.32; range, 2.05 to 5.7), and 22 with anovulatory infertility (median pulsatility index, 3.03; range, 1.6 to 7.0). All the infertile groups had significantly different median pulsatility indexes when compared with the normal group, and the pulsatility indexes correlated with endometrial thickness. CONCLUSIONS: The impedance to uterine artery blood flow is significantly different in women with different causes of infertility as compared with women of normal fertility. Increased resistance to uterine blood flow in the midluteal phase may be an important contributing factor to some causes of infertility and the cause of some previously "unexplained" infertility.

Adult↗

PubMed1994

Comparison of natural with clomiphene citrate-stimulated cycles in in vitro fertilization: a prospective, randomized trial.

OBJECTIVE: To compare the outcome of natural with clomiphene citrate (CC)-stimulated cycles in IVF. DESIGN: Prospective, randomized study. SETTING: Tertiary referral center for assisted conception. SUBJECTS: Thirty patients randomized to receive either no treatment (n = 14) or CC, 100 mg, from days 2 to 6 (n = 16). INTERVENTIONS: Daily ultrasound (US) scan and measurements of serum LH and E2. Ovarian morphology was assessed on baseline US scan. Human chorionic gonadotrophin was administered when the mean diameter of the dominant follicle reached 17 mm. Transvaginal US-directed oocyte recovery was performed 35 hours later. MAIN OUTCOME MEASURES: The number of patients reaching oocyte recovery; numbers of oocytes collected, fertilized and embryos transferred; and clinical pregnancy and multiple pregnancy rates (PRs) were recorded. RESULTS: Ten cycles in the natural cycle group were abandoned before oocyte recovery compared with none in the CC group. There were significantly more follicles > 14 mm (2.4 +/- 0.3 [SE] compared with 0.9 +/- 0.2) and higher peak levels of E2 (375 +/- 67 pg/mL (1,378 +/- 247 pmol/L) compared with 204 +/- 17 pg/mL (748 +/- 61 pmol/L)) in those receiving CC compared with those receiving no drug. All 16 patients treated with CC had oocyte retrieval (mean, 1.8 +/- 0.3 oocytes) compared with only 4 in the natural cycle group (1 oocyte each). The oocyte recovery rate was 95%. Two patients conceived in the CC group (PR per ET, 18%) compared with none in the natural cycle group. Patients with polycystic ovaries developed more large follicles than those with normal ovaries. No patient developed ovarian hyperstimulation syndrome. CONCLUSIONS: Patients undergoing natural cycle IVF are more likely to have abandoned cycles, produce fewer follicles and oocytes, and are less likely to reach ET than patients treated with CC alone. Clomiphene citrate should be considered for use in the context of a conventionally organised IVF-ET program if a mild degree of ovarian stimulation is desired.

Adult↗

PubMed1994

Stimulation of oxidant generation by human sperm suspensions using phorbol esters and formyl peptides: relationships with motility and fertilization in vitro.

OBJECTIVES: To investigate the influence of reactive oxygen species generated by human spermatozoa and contaminating leukocytes on sperm movement and fertilization in vitro. DESIGN: A chemiluminescence technique, using luminol and peroxidase, was used to monitor the generation of reactive oxygen species by human sperm suspensions and the results were correlated with sperm movement and the fertilization of human ova in vitro. SETTING: Diagnostic Andrology Laboratory and IVF Clinic. PATIENTS: Infertile couples undergoing IVF therapy. RESULTS: An N-formyl-methionyl-leucyl-phenylalanine (FMLP) provocation test was used to demonstrate that the presence of leukocytes in 28.5% of the sperm preparations was associated with elevated levels of spontaneous reactive oxygen species production, impaired movement, and a reduced capacity for fertilization in vitro. In the absence of leukocytes, exposure to phorbol ester stimulated a burst of reactive oxygen species generation by human spermatozoa, the magnitude of which was correlated highly with a loss of sperm motility but not with fertilization rates observed in the concurrent IVF cycle. CONCLUSION: Leukocyte contamination of human sperm preparations can be detected readily by FMLP-induced, luminol-dependent chemiluminescence and the results have an important bearing on the fertilizing capacity of the spermatozoa in vitro.

Fertilization↗