Color-Doppler velocimetry of uterine arteries in pregnant and nonpregnant patients during multiovulation induction for IVF

Ultrasound and the receptivity of the endometrium

Ultrasound imaging can be used to assess the endometrium in a number of ways. In particular, time-lapse video recordings can show that the lining of the uterus undergoes rhythmical contractions that vary in strength and intensity throughout the ovarian cycle. These contractions appear to assist in sperm transport at the time of ovulation, but can decrease the chances of a fertilized egg implanting in the uterus if they persist later in the cycle. They are also the cause of ectopic pregnancies occurring in IVF treatment cycles. In order to reduce these uterine contractions and therefore increase the chances of a successful uterine pregnancy, IVF treatment cycles should incorporate minimal stimulation so as to make them as close to natural cycles as possible.

Subendometrial arterial spectral doppler assessment during IVF cycles and its correlation with treatment outcome

The influence of blood flow impedance in subendometrial arteries on embryo implantation rate was investigated by transvaginal sonographic examination in in vitro fertilization (IVF) cycles. A total of 39 women undergoing IVF treatment were evaluated along the treatment cycle. Power and spectral Doppler studies of subendometrial arteries were performed to calculate the pulsatility index (PI), resistance index (RI) and systolic:diastolic ratio (S:D). The correlation between these parameters and pregnancy achievement was analyzed. Patients were grouped according to whether pregnancy was achieved or not. RI and S:D did not differ between the groups along the course of treatment. In pregnant patients, the PI was significantly lower in the beginning of the cycle than on the preovulation day and ovum pickup day. PI in the beginning of the treatment was significantly lower in pregnancy cycles than in nonpregnancy ones. A lower PI on day 1 was correlated with a better chance for pregnancy.

Circadian changes in uterine artery and ovarian stromal blood flow after pituitary down-regulation

OBJECTIVE

To investigate changes in the uterine artery and ovarian stromal blood flow in relation to the time of the day after pituitary down-regulation during in vitro fertilization treatment.

METHODS

Thirteen women were recruited. The uterine artery blood flow was studied using pulsed color Doppler ultrasonography and the ovarian stromal blood flow was measured using three-dimensional power Doppler ultrasonography. Ultrasound scan examinations and blood pressure measurements were performed in the morning and evening.

RESULTS

The diastolic and the mean arterial pressures were significantly higher in the evening. An increase in the uterine artery pulsatility index and resistance index in the evening was observed. The ovarian vascularization index, vascularization flow index, and right ovarian flow index were significantly lower in the evening.

CONCLUSIONS

Despite the small sample size, we have demonstrated the presence of a diurnal change in uterine artery and ovarian stromal blood flow after pituitary down-regulation. Such changes may be related to the systemic change in the sympathetic system and hence vascular resistance. Future study regarding ovarian stromal blood flow should take into account the effect of the time of the day on the readings in order to avoid misleading interpretation of data.

Implantation Failure in Assisted Reproduction Technology and a Critical Approach to Treatment

In this article, we review the literature and our personal experience regarding the many factors that appear to influence implantation rate. Oocyte quality, as determined by patient age and aneuploidies, probably plays a major role in RIF. However, a panoply of other factors have been brought under investigation, quite often with contradictory results and additional intriguing questions to be studied. Infections of the vagina, cervix, and endometrium, the role of mucus aspiration and washing of the cervix on transfer, the role of catheter guidance for a correct transfer and potion of embryos, the effect of mock transfer, and the role of hysteroscopy and its timing before transfer procedures are analyzed both as a review of the literature and as opinions and data from our experience. Many of these factors are interlaced and from the apparently simple issue of trauma, to infections and immune modulation of hatching and implantation, a biological continuum can easily be identified. The impact of abnormalities of the immune system and of homeostasis abnormalities is also covered in a brief overview of reported works and our experience. These latter areas probably constitute the common biological background of all other external factors that, however, the skilled must equip themselves for improving implantation success.

Endometrial and subendometrial perfusion are impaired in women with unexplained subfertility

BACKGROUND

We used three-dimensional power Doppler angiography (3D-PDA) to examine the periodic changes in endometrial development and subendometrial vascularity during the normal menstrual cycle in 29 women with unexplained subfertility and 19 controls.

METHODS

3D-PDA was performed on alternate days from day 3 of the cycle until ovulation and then every 4 days until menses. VOCAL (Virtual Organ Computer-aided AnaLysis) and shell-imaging were used to define and to quantify the power Doppler signal within the endometrial and subendometrial regions producing indices of their relative vascularity.

RESULTS

Women with unexplained subfertility demonstrated significant changes with time (P<0.001) in the indices of vascularity within the endometrium and subendometrium during the menstrual cycle characterized by a pre-ovulatory peak and post-ovulatory fall. These changes mirrored those observed in the control group but were significantly reduced in the endometrium and subendometrium during the mid-late follicular phase and early luteal phase. There were no differences in endometrial thickness or volume between the groups or in the plasma concentrations of estradiol or progesterone.

CONCLUSIONS

Endometrial and subendometrial vascularity are significantly reduced in women with unexplained subfertility during the mid-late follicular phase irrespective of estradiol or progesterone concentrations and endometrial morphometry.

Endometrial receptivity in an in vitro fertilization program as assessed by spiral artery blood flow, endometrial thickness, endometrial volume, and uterine artery blood flow

OBJECTIVE

To investigate the role of sonographic parameters in assessing endometrial receptivity in an in vitro fertilization (IVF) program.

DESIGN

Prospective clinical study.

SETTING

University setting.

PATIENT(S)

One hundred thirty-five patients in our IVF program, selected prospectively on the day of oocyte retrieval.

INTERVENTION(S)

Transvaginal ultrasound examination was performed before oocyte collection.

MAIN OUTCOME MEASURE(S)

Association between implantation rate and spiral artery blood flow (primary outcome measure) and between implantation rate and endometrial measurements as well as uterine artery blood flow (secondary outcome measures).

RESULT(S)

Overall implantation rate was 23.7% per cycle. Subendometrial blood flow was detected in 113 (83.7%) cases, with pregnancy occurring in 21.2%. Mean spiral artery pulsatility index values were 1.12 +/- 0.28 and 1.21 +/- 0.27 for nonconception and conception cycles, respectively. Nondetectable spiral artery blood flow was not associated with a lower implantation rate. Neither endometrial thickness nor endometrial volume was correlated with the likelihood of successful implantation. Minimum endometrial thickness and volume associated with pregnancy were 6.9 mm and 1.59 mL, respectively.

CONCLUSION(S)

Neither Doppler sonography of the spiral or uterine arteries nor measurement of the endometrial thickness or volume allowed a reliable prediction of subsequent IVF outcome.

Association of endometrial blood flow as determined by a modified colour Doppler technique with subsequent outcome of in-vitro fertilization

An endometrial thickness of 10 mm or more has been reported to be favourable for embryo implantation. Nevertheless, many women participating in in-vitro fertilization (IVF) programmes have adequate endometrial thickness but do not achieve satisfactory implantation. With the aid of power Doppler sonography, we examined the association between intra-endometrial vascularity and reproductive outcome. For this study, we enrolled only women with endometrial thickness >/=ISOdia>/=10 mm and excluded those with apparent endometrial pathologies. Of 95 women undergoing IVF cycles, there resulted 37 intrauterine pregnancies. The women were of similar age, body mass index, peak oestradiol concentration and endometrial thickness, and a similar number of embryos were transferred. Those women with an intra-endometrial power Doppler area (EPDA) <5 mm2 achieved a significantly lower pregnancy rate (23. 5 versus 47.5%, P = 0.021) and implantation rate (8.1 versus 20.2%, P = 0.003) than those with an EPDA >/=ISOdia>/=5 mm2. We conclude that, in addition to endometrial thickness, EPDA may serve as a factor indicative of endometrial receptivity. Women with adequate endometrial thickness but a small EPDA tended to have an unfavourable reproductive outcome.

The new obstetrics: its integration into neonatal clinical practise, teaching and research

Most neonatologists have not yet incorporated into their teaching, clinical service and research the advances in high risk obstetrics particularly as it relates to fetal surveillance. This brief review emphasizes some of the "new obstetrics" from the viewpoint of perinatal medicine, particularly in terms of neonatal teaching and the design of future neonatal research. The information that can be obtained about an infant prenatally by the use of ultrasound. power doppler, computerized fetal heart rate monitoring, cordocentesis, etc is extensive and yet, has rarely been utilized in the design of neonatal research protocols. It is becoming imperative that the "new obstetrics" be recognized and utilized in modern neonatal thinking if a truly "perinatal medicine" is to be practised.