Theriogenology question of the month. What are the 3 management options for a mare with twin fetuses at this stage of gestation?

The research is about a study conducted on a Quarter Horse mare that was carrying twin fetuses, with an aim to determine the three potential management options for such a scenario at this stage of pregnancy.

Research Context

• The research revolves around a pregnant, 8-year-old Quarter Horse mare of 450kg, that was observed 150 days after artificial insemination. It aimed to understand its pregnancy status, particularly as the mare was carrying twins.
• This mare had a normal reproductive history and had also previously given birth to live foals for the past two years. In the current breeding scenario, it was artificially inseminated using fresh semen, along with the administration of 3,000 units of human chorionic gonadotropin to induce ovulation.
• No examination to detect pregnancy was conducted prior to the 150th day of breeding.

Examination and Findings

• A transabdominal ultrasonography was employed for the examination using a 3.5-mHz curvilinear probe.
• The ultrasound revealed the presence of two fetuses. One fetus was observed to be smaller than the other based on measurements of their thoracic diameters: the large fetus had a thoracic diameter of 9.6cm, whereas the smaller one had a diameter of 7.6cm.
• Despite these differences in size, both fetuses exhibited normal activity and also a heart rate of about 120 beats per minute. The aspects of the amniotic and allantoic fluids, such as character and amount, were deemed normal, while the fetal membranes appeared normal with appropriate thickness for the stage of gestation.
• The combined thickness of the uterus and fetal membranes, as observed via transrectal ultrasonography, was less than 1.0 cm, while the thickness of the fetuses, as observed via transabdominal ultrasonography, was less than 2.0 cm.

Research Question

• On observing these conditions, the researchers posed a critical question regarding the three possible management options for a mare carrying twin fetuses at this stage of gestation. The study then proceeds to address and respond to this question through further investigation and analysis.