Rau Janina, Tiedemann Daniela, Sielhorst Jutta, Tönissen Anna, Burger Dominik, Martinsson Gunilla, Rohn Karl, Oldenhof Harriette, Sieme Harald
Tierarztl Prax Ausg G Grosstiere Nutztiere. 2018 Jun;46(3):172-177. doi: 10.15653/TPG-170741. Epub 2018 Jun 14.
Transvaginal ultrasound-guided aspiration (TUA) is a procedure which can be used for the reduction of twins post-fixation in the mare. The aim of this study was to evaluate the effect of the age of mares and the day of gestation on the outcome of TUA treatment.
In 88 mares, diagnosed pregnant with twins, TUA of the yolk sac or allantoic fluid was performed between day 30 and 62 of gestation. Mares were aged 3-22 years. Ultrasonographic examination for a viable singleton pregnancy was performed by referring veterinarians 5-7 days and 4 weeks after TUA. Based on reported findings, effects of age and day of gestation on pregnancy rates were evaluated.
Four weeks after TUA, 67% of the cases resulted in a viable singleton pregnancy. Five to 7 days after TUA treatment, the success rate was 74%. The gestational period did not affect the outcome, irrespective of the age of the mare. In contrast, success rates decreased with increasing age of the mares (84% ≤ 7 years vs. 67% 8-14 years vs. 57% ≥ 15 years). In mares aged 8-14 years, a decrease in singleton pregnancies was observed, if TUA was performed after day 35 of gestation. Success rates were slightly higher, if twin vesicles were localized within separate uterine horns (73%) as compared to the same horn (66%). Differences in singleton pregnancy rates were not statistically significant (p > 0.05).
TUA was found to be an effective procedure for reduction of twin pregnancies performed at days 30-62 of gestation. Success rates for singleton pregnancies were high for young mares ≤ 7 years old (84%) and middle aged mares treated before day 36 of pregnancy (74%). Duration of pregnancy at the time of TUA did not have a major impact on the outcome. Nevertheless, the procedure should optimally be performed around days 32-35 of pregnancy to allow for the possibility of natural reduction before treatment and rebreeding in case of a total pregnancy loss after TUA.
经阴道超声引导下抽吸术（TUA）是一种可用于减少母马双胎妊娠的方法。本研究的目的是评估母马年龄和妊娠天数对TUA治疗效果的影响。
对88匹诊断为怀有双胎的母马，在妊娠第30至62天进行卵黄囊或羊水的TUA。母马年龄为3至22岁。在TUA后5至7天和4周，由转诊兽医对单胎存活妊娠进行超声检查。根据报告结果，评估年龄和妊娠天数对妊娠率的影响。
TUA后4周，67%的病例成功获得单胎存活妊娠。TUA治疗后5至7天，成功率为74%。无论母马年龄如何，妊娠期对结果均无影响。相比之下，随着母马年龄的增加成功率下降（≤7岁为84%，8至14岁为67%，≥15岁为57%）。在8至14岁的母马中，如果在妊娠第35天后进行TUA，单胎妊娠会减少。与双胎囊位于同一子宫角（66%）相比，当双胎囊位于不同子宫角时成功率略高（73%）。单胎妊娠率的差异无统计学意义（p>0.05）。
发现TUA是在妊娠第30至62天减少双胎妊娠的有效方法。≤7岁的年轻母马（84%）和在妊娠第36天前接受治疗的中年母马单胎妊娠成功率较高（74%）。TUA时的妊娠期对结果没有重大影响。尽管如此，该手术最好在妊娠第32至35天左右进行，以便在治疗前有自然减少的可能性，并在TUA后完全流产的情况下重新配种。
