A Reduction in Intraovarian Arterial Blood Flow Resistance After Ovulation is Necessary to Achieve Pregnancy in Natural Cycle

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This study examined intraovarian arterial blood flow before and after follicle rupture and found that a significantly greater pregnancy rate occurred when intraovarian arterial resistance decreased after ovulation.

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This prospective study examined intraovarian arterial blood flow resistance before and after follicle rupture in 227 spontaneous natural cycles from 118 infertile patients using transvaginal color flow Doppler imaging, focusing on the pulsatility index (PI) during the periovulatory period and relating it to pregnancy outcomes. Cycles were classified as having severely decreased versus not-severely decreased PI after follicular rupture, and the pregnancy rate per cycle was higher in the severely decreased group (18.6% vs 6.1%), while miscarriage rates were similar between groups. The main limitation is that PI-based grouping is observational and relies on measurements during a periovulatory window within an infertility-treatment context rather than mechanistic evidence. This paper does not explicitly discuss endometriosis or adenomyosis; it was included in the corpus via a keyword match in the upstream search index.

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Abstract

PurposeColor Doppler imaging permits the accurate localization of vessels and high-frequency pulsed Doppler ultrasonography has improved the resolution of flow velocity waveforms. In this study, intraovarian arterial blood flow before and after follicle rupture in the natural cycle was examined using transvaginal color flow Doppler imaging and changes in intraovarian arterial resistance in relation to the outcome of infertility treatment was analyzed.MethodsIn a prospective study, 227 spontaneous cycles in 118 infertile patients who were undergoing infertility treatment at the division of Reproductive Medicine in our center were recruited in this study. The impedance to flow in intraovarian vessels was measured by means of transvaginal color flow Doppler imaging during the periovulatory period in the natural cycle of all patients. The pulsatility index (PI) of intraovarian arterial blood flow and pregnancy rate was evaluated.ResultsOn the basis of PI values before and after follicular rupture, 227 cycles were classified into severely decreased (113 cycles) and not-severely decreased groups (114 cycles). The pregnancy rate per cycle in the severely decreased group was 18.6% (21/113), significantly higher than that in the not-severely decreased group (7/114; 6.1%, p = 0.004). The miscarriage rate was similar in the two groups.ConclusionsA reduction in intraovarian blood vessel resistance is necessary to achieve pregnancy in a natural cycle.
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Abstract

Purpose: Color Doppler imaging permits the accurate localization of vessels and high-frequency pulsed Doppler ultrasonography has improved the resolution of flow velocity waveforms. In this study, intraovarian arterial blood flow before and after follicle rupture in the natural cycle was examined using transvaginal color flow Doppler imaging and changes in intraovarian arterial resistance in relation to the outcome of infertility treatment was analyzed.

Methods

In a prospective study, 227 spontaneous cycles in 118 infertile patients who were undergoing infertility treatment at the division of Reproductive Medicine in our center were recruited in this study. The impedance to flow in intraovarian vessels was measured by means of transvaginal color flow Doppler imaging during the periovulatory period in the natural cycle of all patients. The pulsatility index (PI) of intraovarian arterial blood flow and pregnancy rate was evaluated.

Results

On the basis of PI values before and after follicular rupture, 227 cycles were classified into severely decreased (113 cycles) and not-severely decreased groups (114 cycles). The pregnancy rate per cycle in the severely decreased group was 18.6% (21/113), significantly higher than that in the not-severely decreased group (7/114; 6.1%, p = 0.004). The miscarriage rate was similar in the two groups.

Conclusions

A reduction in intraovarian blood vessel resistance is necessary to achieve pregnancy in a natural cycle. Similar content being viewed by others

References

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