Supplementary table. Overview of the most extensive published studies on the causes of pregnant loss and neonatal death.
Diagnostic category / Giles et al. 1993*USA, Kentucky
3527 cases (5 years)
Abortion, stillbirth, neonatal mortality within 24h / Tengelsen et al. 1997
USA, Michigan
290 cases (12 years)
Abortion, stillbirth / Smith et al. 2003
UK
1252 cases (10 years)
Abortion, stillbirth, neonatal mortality within 7 days / Laugier et al. 2011
France, Normandy
1822 (24 years)
Abortion / Butler et al. 2011
UK
976 cases (5 years)
Abortion / Williams 2011
USA, Kentucky
1308 cases (2years, 2008-2009)
Abortion / Marenzoni et al. 2012
Italy
106 cases (7 years)
Abortion, stillbirth, neonatal mortality within 7 days
EHV-1 / 142
(108 isolated) (0.4%) / 26 (9%) / 78 (0.06%) / 126 (6.9%) / 125 (12.8%) / 25 (1.9%)
defined as viral abortion / 22 (20.7%)
EHV-4 / 1 (1/109 EHV isolated) (0.02) / 0 (0%) / 4 (0.03%) / 4 (0.2%) / 10 (1%) / 0 (0%)
EVA / 0 (0%) / 0 (0%) / 0 (0%) / 1 (0.05%) / 0 (0%) / 0 (0%)
Septicaemia / 1183 (33.5%) (defined as fetoplacental infection) / 18 (6.2%) / 40 (3.2%) / 695 (38.1%) / 109† (11.7%) / 48 (3.7%) / 20 (18.9%)
Placentitis / 37 (12.7%) / 105 (8.4%) / 57 (3.1%) / n.r. / 174 (13.3%) / 6 (5.6%)
Fungal placentitis / 61 (1.7%) / 4 (1.3%) / 18 (1.4%) / 16 (0.9%) / † / n.r. / 1 (0.9%)
Placentitis without identified agent / 351 (9.9%) / 8 (2.7%) / nr / 27 (1.5%) / n.r. / n.r. / 3(2.8%)
Umbelical cord disorders / 121 (3.4%) / 14 (4.8%) / 492 (39.3%) / 300 (16.5%) / 258 (26.4%) / 126 (9.6%) / 6 (5.6%)
Placental villous hypoplasia or atrophy / 71 (2%) / n.r. / # / 86 (4.7%) / n.r. / n.r. / 1 (0.9%)
Congenital anomalies / 536 ‡ (15.2%) / 14 (4.8%) / # / 34 (1.9%) / § / n.r. / 1 (0.9%)
Twinning / 221 (6.2%) / 12 (4.1%) / 75 (6%) / 27 (14.8%) / § / n.r. / 0 (0%)
Premature placental separation / 91 (2.6%) / n.r. / # / 16 (0.9%) / § / n.r. / 4 (3.7%)
Placental edema / 158 (4.5%) / n.r. / n.r. / 14 (0.8%) / n.r. / n.r. / 0 (0%)
Body pregnancy / 10 (0.2%) / n.r. / # / 7 (0.4%) / n.r. / n.r. / 2 (1.8%)
Placental dystrophic calcification / n.r. / 6 (2%) / n.r. / n.r. / n.r. / n.r. / 3(2.8%)
Dystocia / 196 (5.5%) / 3 (1%) / 161″ (12.8%) / n.r. / § / ¥ / 1 (0.9%)
Trauma / 50% of the dystocia cases / 5 (1.7%) / # / n.r. / n.r. / ¥ / 1 (0.9%)
Noninfectious maternal disease / 15 (0.4%) / n.r. / # / 11 (0.6%) / n.r. / n.r. / 2 (1.8%)
Neonatal asphyxia / 483 (13.7%) / n.r / n.r. / n.r. / n.r. / ¥ / 0 (0%)
Miscellaneous / Not counted / 2^ (0.06%) / 171# (13.6%) / n.r. / 191§ (19.6%) / 387¥ (29.6%) / 2 (1.8%)¶
No diagnosis / 585 (16.6%) / 95 (32.7%) / 98 (7.8%) / 457 (25.1%) / 282 (28.9%) / 289 (22.1%) / 38 3 (35.8%)
*It could comprise the two papers of Hong et al.1993.
n.r.: not reported;
† It consisted of both bacterial and fungal infection;
‡ 188 cases consisted of contracted foal syndrome;
″ defined as intrapartum stillbirth;
^It comprises cancer and adenomatoid hyperplasia;
#It is comprised in the miscellaneous. Miscellaneous in this work consisted of congenital anomalies, cancer, premature placental separation, body pregnancy, villus hypoplasia, amniotic rupture, neonatal maladjustement syndrome, post-natal trauma, maternal disease;
§ It is comprised in the miscellaneous. Miscellaneous in this work consisted of congenital anomalies, premature placental separation, dystocia, stillbirth and twinning.
¥ It is comprised in the miscellaneous. Miscellaneous in this work consisted of trauma, dystocia, and asphyxia.
¶ It comprises two cases of Equine Infectious Anaemia.
NOTES:
-The definition of the cases is different among the papers (only abortion vs abortion+stillbirth+neonatal mortality). The definition of neonatal mortality is different because for Giles et al. (1993)it is defined as death of foal within 24 hours and for Smith et al. (2003) it is defined as death of foal within 7 days.
Also the definition of the miscellaneous is different among different works and in some cases it consists of other categories identified in the other works.
Then it could be very useful to do an international checklist to make comparable results of different countries.
-Different percentages of the categories could reflect differences in equine population (for example breed, type of fecundation, etc) or in environment;
-The data available of the equine abortion at international level are quite limited in temporal and spatial dimensions; this is an important aspect because during the time the diagnostic techniques and the knowledge about etiological agents usually improve;
-The fetal diarrhea syndrome was not included in the diagnostic categories because it is considered secondary to chronic placentitis, pregnancy with twins, or any other abnormality that could cause placental insufficiency (Giles et al. 1993).
-It should be considered that dystocia is due to different reasons: oversize, malpresentation, unattended foalings, and so on.