Abstract:

Reproductive success is vital in sustaining free-ranging bottlenose dolphin (Tursiops truncatus) populations and is a critical component of managed care. Ultrasonography has proven to be invaluable in wild dolphin health assessments and in marine mammal preventative medicine. It is also a non-invasive standard of care in assessing the fetomaternal unit in humans and animals, including dolphins and horses. The purpose of this prospective longitudinal study was to develop a protocol for fetomaternal ultrasonographic monitoring in Tursiops truncatus and to report normal measurements and descriptive findings correlated with a positive outcome. From 2010-2017, serial ultrasonographic evaluations of 12 healthy dolphins in managed care were performed over the course of 16 pregnancies. A total of 203 ultrasound exams were conducted, including parameters such as fetal biparietal diameter (BPD), thoracic width in dorsal and transverse planes, thoracic height in a sagittal plane, aortic diameter, blubber thickness, uteroplacental thickness, and lung: liver mean pixel intensity.

Suggested Citation:

Marina Ivančić, Forrest M. Gomez, Whitney B. Musser, Ashley Barratclough, Jennifer M. Meegan, Sophie M. Waitt, Abraham Cárdenas Llerenas, Eric D. Jensen, Cynthia R. Smith. 2019. Ultrasonographic findings associated with normal pregnancy and fetal well-being in the bottlenose dolphin (Tursiops truncatus). Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/n7-eydg-cy02

Purpose:

These data were used to establish ultrasonographic characteristics of normal pregnancy in dolphins, including an updated equation for prediction of parturition date in Tursiops. Future applications of these normal data will help identify in utero abnormalities indicative of fetal distress and morbidity, and further, improve understanding of reproductive failure in wild and managed populations.

Data Parameters and Units:

Exam.ID (Unique identification number for each reproductive ultrasound (US) exam conducted); Animal.ID (Unique identification number for each dolphin in the dataset); Exam.date (Date of the exam, mm/dd/yyyy); Parturition.date (Date of parturition, mm/dd/yyyy); Est.fetal.age.biparietal (Estimated fetal age based on the biparietal diameter on the date of the exam (days) calculated using the following equation: gestational age (d) =380-(348.16-(26.03*BPD(cm)); Est.conception.date (Estimated date of conception based on the actual birth date assuming gestation of 380 days, mm/dd/yyyy); Est.fetal.age.380 (Estimated fetal age based on the actual birth date assuming gestation of 380 days, days); GH.side (Gravid uterine horn: Left (L) or Right (R)); Fetal.sex (Sex of fetus determined by resultant calf: Male (M) or Female (F)); L.ovary.eval (Left ovary evaluated: Y/N); LO.condition (Condition of the left ovary as determined by veterinarian's examination: Normal or Abnormal); LO.activity (Activity of the left ovary as determined by veterinarian's examination: Active or Quiescent); LO.follicles (Presence of follicles on the left ovary: Y/N); LO.fol.num (If follicles are present on the left ovary, how many: 1, 2 or >3); LO.fol.max.diameter (If follicles are present on the left ovary, the maximum diameter of the dominant follicle (cm)); LO.CL (Presence of CL on the left ovary: Y/N); LO.CL.max.diameter (If a CL is present on the left ovary, the maximum diameter (cm)); LO.CL.orth.diameter (If a CL is present on the left ovary, the orthogonal to the maximum diameter (cm)); LO.CS (If a CL is present on the left ovary, are a cyst-like structure(s) present: Y/N); LO.CS.max.diameter (If cyst-like structure(s) are present on the left ovary, the maximum diameter (cm)); LO.CS.orth.diameter (If cyst-like structure(s) are present on the left ovary, the orthogonal to the maximum diameter (cm)); LO.CS.multiple (If cyst-like structure(s) are present on the left ovary, are there more than 1: Y/N); R.ovary.eval (Right ovary evaluated: Y/N); RO.condition (Condition of the right ovary as determined by veterinarian's examination: Normal or Abnormal); RO.activity ( Activity of the right ovary as determined by veterinarian's examination: Active or Quiescent); RO.follicles (Presence of follicles on the right ovary: Y/N); RO.fol.num (If follicles are present on the right ovary, how many: 1, 2 or >3); RO.fol.max.diameter (If follicles are present on the right ovary, the maximum diameter of the dominant follicle (cm)); RO.CL (Presence of CL on the right ovary: Y/N); RO.CL.max.diameter (If a CL is present on the right ovary, the maximum diameter (cm)); RO.CL.orth.diameter (If a CL is present on the right ovary, the orthogonal to the maximum diameter (cm)); RO.CS (If a CL is present on the right ovary, are a cyst-like structure(s) present: Y/N); RO.CS.max.diameter (If cyst-like structure(s) are present on the right ovary, the maximum diameter (cm); RO.CS.orth.diameter (If cyst-like structure(s) are present on the right ovary, the orthogonal to the maximum diameter (cm)); RO.CS.multiple (If cyst-like structure(s) are present on the right ovary, are there more than 1: Y/N); L.GHP.eval (Gravid uterine horn and placenta evaluated scanning on the left side of the animal: Y/N); L.GHP.condition (Condition of the gravid uterine horn and placenta scanning on the left side of the animal: Normal or Abnormal); L.UPU.cranial (Mean thickness of the 'cranial' UPU of the gravid uterine horn scanning on the left side of the animal (cm). Measurements were obtained in triplicate, separated by 0.5cm in the 1st trimester and 1.0cm thereafter. 'Cranial' was the most cranial uterine margin in contact with the dam's body wall); L.UPU.cranial.max (Maximum thickness of the 'cranial' UPU of the gravid uterine horn scanning on the left side of the animal (cm). 'Cranial' was the most cranial uterine margin in contact with the dam's body wall); L.UPU.cranial.min (Minimum thickness of the 'cranial' UPU of the gravid uterine horn scanning on the left side of the animal (cm). 'Cranial' was the most cranial uterine margin in contact with the dam's body wall); L.UPU.mid (Mean thickness of the 'mid' UPU of the gravid uterine horn scanning on the left side of the animal (cm). Measurements were obtained in triplicate, separated by 0.5cm in the 1st trimester and 1.0cm thereafter. 'Mid' was the subjective midpoint between 'cranial' and 'caudal' UPU and was not measured during the 1st trimester due to small uterine size); L.UPU.mid.max (Maximum thickness of the 'mid' UPU of the gravid uterine horn scanning on the left side of the animal (cm). 'Mid' was the subjective midpoint between 'cranial' and 'caudal' UPU and was not measured during the 1st trimester due to small uterine size); L.UPU.mid.min (Minimum thickness of the 'mid' UPU of the gravid uterine horn scanning on the left side of the animal (cm). 'Mid' was the subjective midpoint between 'cranial' and 'caudal' UPU and was not measured during the 1st trimester due to small uterine size); L.UPU.caudal (Mean thickness of the 'caudal' UPU of the gravid uterine horn scanning on the left side of the animal (cm). Measurements were obtained in triplicate, separated by 0.5cm in the 1st trimester and 1.0cm thereafter. 'Caudal' was just cranial to the normal broadening of the UPU seen near the ovary); L.UPU.caudal.max (Maximum thickness of the 'caudal' UPU of the gravid uterine horn scanning on the left side of the animal (cm). 'Caudal' was just cranial to the normal broadening of the UPU seen near the ovary); L.UPU.caudal.min (Minimum thickness of the 'caudal' UPU of the gravid uterine horn scanning on the left side of the animal (cm). 'Caudal' was just cranial to the normal broadening of the UPU seen near the ovary); L.UPU.disr (Presence of disruptions in the uteroplacental contact of the gravid horn scanning on the left side of the animal: Y/N); L.UPU.disr.num (If UPU disruptions are observed in the uteroplacental contact of the gravid uterine horn scanning on the left side of the animal, how many (n)); L.UPU.disr.per (If UPU disruptions are observed in the uteroplacental contact of the gravid uterine horn scanning on the left side of the animal, what percentage is affected (%)); R.GHP.eval (Gravid uterine horn and placenta evaluated scanning on the right side of the animal: Y/N); R.GHP.condition (Condition of the gravid uterine horn and placenta scanning on the right side of the animal: Normal or Abnormal); R.UPU.cranial (Mean thickness of the 'cranial' UPU of the gravid uterine horn scanning on the right side of the animal (cm). Measurements were obtained in triplicate, separated by 0.5cm in the 1st trimester and 1.0cm thereafter. 'Cranial' was the most cranial uterine margin in contact with the dam's body wall); R.UPU.cranial.max (Maximum thickness of the 'cranial' UPU of the gravid uterine horn scanning on the right side of the animal (cm). 'Cranial' was the most cranial uterine margin in contact with the dam's body wall); R.UPU.cranial.min (Minimum thickness of the 'cranial' UPU of the gravid uterine horn scanning on the right side of the animal (cm). 'Cranial' was the most cranial uterine margin in contact with the dam's body wall); R.UPU.mid (Mean thickness of the 'mid' UPU of the gravid uterine horn scanning on the right side of the animal (cm). Measurements were obtained in triplicate, separated by 0.5cm in the 1st trimester and 1.0cm thereafter. 'Mid' was the subjective midpoint between 'cranial' and 'caudal' UPU and was not measured during the 1st trimester due to small uterine size); R.UPU.mid.max (Maximum thickness of the 'mid' UPU of the gravid uterine horn scanning on the right side of the animal (cm). 'Mid' was the subjective midpoint between 'cranial' and 'caudal' UPU and was not measured during the 1st trimester due to small uterine size); R.UPU.mid.min (Minimum thickness of the 'mid' UPU of the gravid uterine horn scanning on the right side of the animal (cm). 'Mid' was the subjective midpoint between 'cranial' and 'caudal' UPU and was not measured during the 1st trimester due to small uterine size); R.UPU.caudal (Mean thickness of the 'caudal' UPU of the gravid uterine horn scanning on the right side of the animal (cm). Measurements were obtained in triplicate, separated by 0.5cm in the 1st trimester and 1.0cm thereafter. 'Caudal' was just cranial to the normal broadening of the UPU seen near the ovary); R.UPU.caudal.max (Maximum thickness of the 'caudal' UPU of the gravid uterine horn scanning on the right side of the animal (cm). 'Caudal' was just cranial to the normal broadening of the UPU seen near the ovary); R.UPU.caudal.min (Minimum thickness of the 'caudal' UPU of the gravid uterine horn scanning on the right side of the animal (cm). 'Caudal' was just cranial to the normal broadening of the UPU seen near the ovary); R.UPU.disr (Presence of disruptions in the uteroplacental contact of the gravid horn scanning on the right side of the animal: Y/N); R.UPU.disr.num (If UPU disruptions are observed in the uteroplacental contact of the gravid uterine horn scanning on the right side of the animal, how many (n)); R.UPU.disr.per (If UPU disruptions are observed in the uteroplacental contact of the gravid uterine horn scanning on the right side of the animal, what percentage is affected (%)); Umb.eval (Umbilical cord evaluated: Y/N); Umb.vessels (Number of blood vessels visualized in the umbilical cord (n)); Umb.max.diameter (Maximum diameter of the umbilical cord in cross-section at the site of fetal attachment (cm)); Umb.abns (Presence of umbilical cord abnormalities: Y/N); Umb.abns.descr (Description of any umbilical cord abnormalities); Umb.doppler (Blood flow confirmed by color flow doppler: Y/N); Umb.urachus (Urachus (allantoic duct) visualized in umbilical cord: Y/N); Umb.fetal.att (Fetal attachment of the umbilical cord visualized: Y/N); Umb.placental.att (Placental attachment of the umbilical cord visualized: Y/N); Fluid.eval (Uterine fluid evaluated: Y/N); Uterine.fluid (If amniotic and allantoic fluid cannot be distinguished, echogenicity of uterine fluid: Anechoic, Hypoechoic or Hyperechoic); UF.FFPs (Presence of free-floating particles (FFPs) in uterine fluid: Y/N); UF.max.depth (Maximum depth of uterine fluid (cm)); All.fluid (Echogenicity of the allantoic fluid: Anechoic, Hypoechoic or Hyperechoic); All.FFPs (Presence of free-floating particles (FFPs) in allantoic fluid: Y/N); All.max.depth (Maximum depth of allantoic fluid (cm)); Amn.fluid (Echogenicity of the amniotic fluid: Anechoic, Hypoechoic or Hyperechoic); Amn.FFPs (Presence of free-floating particles (FFPs) in amniotic fluid: Y/N); Amn.max.depth (Maximum depth of amniotic fluid (cm)); Fetus.eval (Fetus evaluated: Y/N); Biparietal.diameter (Biparietal diameter (cm)); Trimester.number (Trimester: 1st, 2nd or 3rd); Thorax.dorsal (Thoracic diameter measured at the level of the heart left-to-right in a dorsal plane (cm)); Thorax.sagittal (Thoracic diameter measured at the level of the heart dorsal-to-ventral in a sagittal plane (cm)); Thorax.transverse (Thoracic diameter measured at the level of the heart left-to-right in a transverse plane (cm)); Fetal.sex.us (Fetal sex determined ultrasonographically in utero if genitalia could be identified: Male (M) or Female (F)); Cardiac.movement (Detection of fetal cardiac movement: Y/N); Mmode.HR (Mean fetal heart rate, obtained in triplicate, calculated in M-mode (bpm)); Aorta.diameter (Mean aortic diameter, measured in triplicate, from lumen-to-lumen close to the heart (cm)); Eye.max.diameter (Maximum diameter of the fetal eye globe spanning the inner margins of the vitreous body (cm)); Eye.orth.diameter (Orthogonal to the maximum diameter of the fetal eye globe spanning the inner margins of the vitreous body (cm)); Fetal.movement (Fetal movement subjectively graded by veterinarian: None, Rare, Frequent or Continuous); Pleural.effusion (Presence of pleural effusion: Y/N); Heart.abns (Presence of abnormalities of the heart: Y/N); Lung.echo (Echogenicity of the lung as compared to the echogenicity of the liver: Hyperechoic, Hypoechoic or Isoechoic); Lung.homog (Homogeneity of the lung tissue: Homogeneous or Heterogeneous); Lung.MPI (Mean pixel intensity (MPI), a unitless value to quantify echogenicity, of the lung tissue. This value is calculated using an 8-bit grayscale with 256 shades of gray); Liver.MPI (Mean pixel intensity (MPI), a unitless value to quantify echogenicity, of the liver tissue. This value is calculated using an 8-bit grayscale with 256 shades of gray); MPI.ratio (Calculated lung/liver ratio of mean pixel intensity (MPI)); Peritoneal.effusion (Presence of peritoneal effusion in the abdomen: Y/N); Forestomach.abns (Presence of abnormalities of the forestomach: Y/N); Forestomach.fluid (Presence of fluid in the forestomach: Y/N); Kidney.abns (Presence of abnormalities of the kidneys: Y/N); Bladder.abns (Presence of abnormalities of the bladder: Y/N); Bladder.fluid (Presence of fluid in the forestomach: Y/N); Blubber.thickness (Thickness of the blubber layer measured close to the level of the heart on the dorsum (cm)). Note: Unless otherwise specified, the following acronyms apply throughout this dataset. Y = Yes N = No NA = Not applicable ND = No data UPU = uteroplacental unit CL = corpus luteum CS = cyst-like structure LO = Left Ovary RO = Right Ovary

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