Fig. 1

Photographs of the double-stained endoskeleton of fetuses and their body parts from different groups. a Control group; normal ossification of the cranial, forelimbs and hindlimbs bones, complete ossification of the vertebral column and normal appearance of ribs. b Ginger group; normal ossification of the endoskeleton. c Labetalol group; severe lack of ossification in the whole skeleton, loss of some cranial bones (blue arrow), wavy ribs (red arrow) and costal separation anomaly (black arrows). Also, some fetuses showed pinpoint ossification areas in the hummers, radius and ulna of the right forelimb and in the femur and ileum of the right and left hind limbs. d Labetalol + ginger group; overall amelioration in the ossification of the endoskeleton but some bones of the skull, vertebral column and limbs with incomplete, slight or lacking ossification can be seen. Atlas (At), axis (Ax), carpus (Ca), caudal vertebrae (Cav), cervical vertebrae (Cv), exoccipital (Eo), frontal (F), femur (Fe), fibula (Fi), humerus (Hu), ilium (IL), interparietal (Ip), ischium (Is), lumbar vertebrae (Lv), metacarpus (Mc), mandible (Mn), metatarsus (Mt), nasal (n), parietal (P), phalanges (Ph), pre-maxilla (Pre-M), radius (R), ribs (Ri), squamosal (S), scapula (Sc), supraoccipital (So), sternebrae (St), sacral vertebrae (Sv), tibia (T), thoracic vertebrae (Tv), ulna (U), xiphoid process (XP), zygomatic (Zy) (Alizarin red S and Alcian blue)