Management of monozygotic twins in the mare

In the horse, only a small number of monozygotic twins and triplets have been reported commonly, outcome is poor. As in man, an association between occurrence use assisted reproductive technologies (ART) has suggested. mare, transfer vitro produced (IVP) embryos appears to increase incidence twinning (1.6%; 4/254) compared vivo (0%; 0/413) (Dijkstra et al. Equine Vet J. 2020; 52: 258-261). Due type placental arrangement, these twin pregnancies are difficult reduce singleton using reduction techniques commonly applied dizygotic twins. this report, 8 cases presented, all which resulted from single IVP embryo. Seven were presumed be monochorionic diamniotic/diallantoic one dichorionic diamniotic/diallantoic, based on membrane classification by ultrasound and/or post-expulsion examination. Similar previously described cases, pregnancy became apparent at 25 days gestation, when two with heartbeat visualized. Depending gestational stage, different applied. case, referred day 40 gestation andclassified as transvaginal guided aspiration (TUGA) was performed. Reduction other performed per rectum compression fetal thorax 65 gestation. cranio-cervical dislocation 75-80 Finally, transcutaneous attempted 120 case. However, 6 treated successfully reduced, resulting live foal born following gestation; death both fetuses. addition, remaining (2/8) lost their spontaneously around 42 months whereby latter presence not established previous examinations. Based limited thoracic method These results highlight need for further investigation into best method, depending stage how much demise fetus affects survival its co- twin, may depend arrangement.