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 report measurements and descriptive findings from pregnancies in wild northern Gulf of Mexico dolphins. Ultrasonographic evaluations were performed on 43 pregnant dolphins during health assessments conducted in Barataria Bay, Louisiana from 2011-2018. Outcomes of these 43 pregnancies included 9 successful, 28 failed and 6 unknown with 35 exams collected during the first trimester, 7 from the second trimester, and only 1 exam from the third trimester. Ultrasound analysis was comprised of up to 70 parameters per exam including potential biophysical predictors of failure such as changes in corpus luteum size, changes in uteroplacental thickness, placental abruption, decreased fetal lung/liver ratio, and umbilical cord abnormalities.

Suggested Citation:

Forrest M. Gomez, Whitney B. Musser, Jennifer M. Meegan, Cynthia R. Smith. 2019. Ultrasonographic findings associated with pregnancy or fetal well-being in the bottlenose dolphins (Tursiops truncatus) during health assessments conducted in Barataria Bay, Louisiana from 2011-08-03 to 2018-07-19. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/n7-63bk-a322

Purpose:

These data were used to 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 (month/day/year) Pregnancy.outcome Outcome of the pregnancy as determined by visual reproductive outcome surveys >2wks after the estimated due date: Success, Fail or could not be determined (CBD) Est.due.date Estimated due date based on estimated date of conception assuming a gestation of 380 days (month/day/year) Est.fetal.age.biparietal Estimated fetal age based on the biparietal diameter (BPD; cm) on the date of the exam (days) calculated using the following equation: gestational age (days) = 380-(348.16-(26.03*BPD)) Est.conception.date Estimated date of conception based on biparietal diameter (month/day/year) GH.side Gravid uterine horn: Left (L) or Right (R) 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.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 Presence of cyst-like structure(s) (follicular or persistent): Y/N LO.CS.max.diameter If cyst-like structure(s) (follicular or persistent) are present on the left ovary, the maximum diameter (cm) LO.CS.orth.diameter If cyst-like structure(s) (follicular or persistent) are present on the left ovary, the orthogonal to the maximum diameter (cm) LO.CS.multiple If cyst-like structure(s) (follicular or persistent) 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.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 Presence of cyst-like structure(s) (follicular or persistent): Y/N RO.CS.max.diameter If cyst-like structure(s) (follicular or persistent) are present on the right ovary, the maximum diameter (cm) RO.CS.orth.diameter If cyst-like structure(s) (follicular or persistent) are present on the right ovary, the orthogonal to the maximum diameter (cm) RO.CS.multiple If cyst-like structure(s) (follicular or persistent) 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.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. R.GHP.eval Gravid uterine horn and placenta evaluated scanning on the right side of the animal: Y/N 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. Umb.eval Umbilical cord evaluated: Y/N Umb.vessels Number of blood vessels visualized in 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 colorflow 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) Manual.HR Mean manual heart rate, obtained in triplicate (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 Hyperechoic.abdomen Presence of hyperechoic foci in the abdomen: Y/N Hyperechoic.abdom.grade If hyperechoic abdomen present, subjectively graded by echogenicity: 1, 2 or 3 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 bladder: Y/N Blubber.thickness Thickness of the blubber layer measured close to the level of the heart on the dorsum (cm) Maternal.abdominal.effusion Presence of maternal abdominal effusion: Y/N Mat.abdom.eff.grade If maternal abdominal effusion is present, subjectively graded: Scant, Mild, Moderate or Severe

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