Bidimensional and Doppler ultrasonographic evaluation of postpartum uterine involution in the queen

Ovarian and uterine two-dimensional and Doppler ultrasonographic changes in the feline peri-estrus period

OBJECTIVES

The aim of this study was to evaluate two-dimensional and Doppler ultrasonographic changes of the ovary and uterus during estrus and the early post-estrus period in domestic cats.

METHODS

Two-dimensional and Doppler ultrasonographic evaluations of the ovaries and uterus were performed in seven queens on days 1, 3 and 5 of estrus, and 5 days after estrus (AE5).

RESULTS

On day 1, 5.4 ± 0.5 follicles of 2.1 ± 0.1 mm were detected progressively increasing in number and size up to day 5 and then decreased on AE5 (P <0.05). A maximum follicular diameter of 4.1 ± 0.1 mm was achieved on day 5. Both during and after estrus, the uterus was generally hypoechoic compared with the surrounding tissues and delineated by a thin hyperechoic line corresponding to the serosa. In some animals, the uterine layers were distinguished during and after estrus. The blood flow waveforms of the intraovarian and uterine arteries were characterized by a systolic peak and diastolic flow extending throughout the remainder of the cardiac cycle to the next systole. In the uterine artery waveforms, the early diastolic notch was mild or absent during most estrous observations. The resistance index of the intraovarian arteries decreased up to day 5, and then increased on AE5 (P <0.05). The resistance index of the uterine arteries was lower during estrus than in the post-estrus period (P <0.05).

CONCLUSIONS AND RELEVANCE

It is concluded that in the domestic cat, follicular number and diameter as well as ovarian and uterine blood flow changed during and immediately after estrus. Doppler ultrasound proved suitable to evaluate the hemodynamic changes involved in the cyclic remodeling of ovarian and uterine tissues that occurs during and after follicular growth in domestic cats.

Advanced ultrasound techniques in small animal reproduction imaging

Ultrasonography is the imaging technology of choice for the evaluation of the reproduction system and of pregnancy in both humans and animals. Over the past 10 years, there have been significant technological improvements of the equipment, while new technologies have been developed. Doppler, contrast-enhanced ultrasonography, elastography, and 3D/4D ultrasonography are advanced ultrasound techniques that have been designed as methods to increase the diagnostic sensitivity of two-dimensional (b-mode) ultrasound, and not as stand-alone tests. The basic physics as well as the advantages and limitations of these advanced ultrasound methods are briefly described. In the reproductive diagnostics of small animals, these techniques have gained an increased popularity as proved by the increased publication of several reports that are also briefly summarized in this review. Clinical applicability is to date limited because of a lack of research on the diagnostic value in concrete situations. Future research projects should focus also on standardization of the used techniques, on determination of thresholds to discriminate between healthy or diseases or fertile versus infertile and on the predictive value of advanced ultrasound findings. Continuing development and optimization of different ultrasound techniques as well as the increase of related scientific interest and worldwide research promises that the clinical interest on the use of advanced ultrasound techniques will increase in future.

Hemodynamics of the uterine and umbilical arteries during the perinatal period in ewes

Examining feto-maternal blood flow is extremely important for accurate prenatal control and predicting adverse conditions during puerperium. We aimed to analyze blood flow of uterine artery (UA) and umbilical artery (UMA) from and subsequent to mid-gestation, lambing and postpartum of 15 ewes, subjected to lambing induction with aglepristone. Hemodynamic variables, diameter and blood flow of UA and UMA were determined by Doppler and B-mode ultrasonography at 60, 90 and 120 days of pregnancy, at 12 h before, 12 h after first aglepristone injection and 12 h after induction and days 1, 3, 5, 7, 15 and 30 after lambing. The UMA peak systolic:diastolic velocity (S/D), resistance index (RI) and pulsatility index (PI) decreased from mid-pregnancy until 120 d, whereas peak systolic velocity (PSV), end diastolic velocity (EDV) and time average maximum velocity (TAMAX) increased towards 120 d. The UMA RI additionally decreased at 12 h after lambing induction. The UMA diameter and volume increased from mid-gestation until 12 h before lambing induction. UA PSV and TAMAX increased from 60 until 90 days of pregnancy, while EDV, PSV and TAMAX decreased soon after parturition, with a further reduction at 7 days. The UA diameter and volume decreased during postpartum, stabilizing by 15 days after parturition. In conclusion, pregnancy is marked by progressive increase in uterine and umbilical blood flow, while lambing acutely diminishes umbilical vascular resistance, suggesting lack of progesterone influence on vasodilation. Conversely, puerperium is characterized by reduction in uterine blood supply mostly within the first 2 weeks of postpartum in sheep.

Postpartum uterus involution observed by real-time ultrasound scanning and vaginal cytology in Van cats

OBJECTIVES

The objective was to investigate postpartum uterus involution by real-time ultrasonography and vaginal cytology in Van cats.

METHODS

This study included 15 healthy Van cats belonging to the Van Cat Research Centre (Yuzuncu Yil University, Van, Turkey). Starting 24 h postpartum, ultrasonographic measurements were performed on the placental and interplacental uterine horn regions every day. Decreases in the diameters and uterine content were considered as criteria for uterine involution. Vaginal discharge samples were collected every day for 4 weeks postpartum. The smears were stained with Papanicolaou stain.

RESULTS

The average diameters of placental and interplacental regions (IPRs) in the uterine horns were 3.12 ± 0.29 cm and 2.36 ± 0.43 cm, respectively, at 24 h postpartum. Placental regions (PRs) shrank faster than IPRs. At 48 h postpartum, it became difficult to distinguish PRs from IPRs in the uterine horns. The uterine horns could be seen in the abdominal cavity up to 5.60 ± 0.99 days postpartum. The mean of the last assessable diameter of the uterine horns from days 4 to 7 in all cats was 0.49 ± 0.07 cm. The vaginal epithelial cells appeared to be under the effect of oestrogen for 4 weeks postpartum.

CONCLUSIONS AND RELEVANCE

The morphological involution of the uterus completes, to a large extent, within the first 48 h postpartum in Van cats. A more detailed hormonal analysis would contribute greatly to the understanding of the physiological processes involved in this period. Although postpartum involution appeared complete by 5.60 ± 0.99 days after parturition in Van cats, histological verification of this finding is needed.