Title: Relaxin as a hormonal aid to evaluate pregnancy and pregnancy loss in bottlenose dolphins (Tursiops truncatus).
Authors: Bergfelt, Don R; Blum, Jason L; Steinetz, Bernard G; Steinman, Karen J; O'Brien, Justin K; Robeck, Todd R
Published In Gen Comp Endocrinol, (2017 02 01)
Abstract: This study was conducted to critically evaluate weekly and monthly circulating concentrations of immunoreactive relaxin throughout pregnancies that resulted in live births, stillbirths, and abortions in aquarium-based bottlenose dolphins. A relaxin RIA was used to analyze serum collected during 74 pregnancies involving 41 dolphins and 8 estrous cycles as well as 8 non-pregnant dolphins. Pregnancies resulted in live births (n=60), stillbirths (n=7), or abortions (n=7). Relative to parturition (Month 0), monthly changes (P<0.0001) in relaxin was indicated by relatively low concentrations during early pregnancy (Months -12 to -9) which subsequently increased (P<0.05) during mid- (Months -8 to -5) to late (Months -4 to -1) pregnancy; relaxin was highest (P<0.05) at the time of parturition. Post-parturition (Month 1), concentrations decreased (P<0.05). During the first 4weeks post-ovulation, relaxin concentrations were not different between pregnant and non-pregnant dolphins (status-by-week interaction, P=0.59). Status-by-month interaction (P<0.0002) involving different pregnancy outcomes was due, impart, to an increase in relaxin during early pregnancy (P<0.05) that was comparable among dolphins with live births, stillbirths, and abortions except concentrations were lower (P<0.05; 52%) at mid-pregnancy in association with pregnancy loss. Thereafter, concentrations increased (P<0.05) during late pregnancy in dolphins with stillbirths but not in dolphins with abortions. In conclusion, this study provided new information on the pregnancy-specific nature of relaxin, critical evaluation of the fundamental characteristics of relaxin during pregnancy and pregnancy loss, and clarification on the strengths and limitations of relaxin as a diagnostic aid to determine pregnancy status and assess maternal-fetal health in bottlenose dolphins.
PubMed ID: 26724576
MeSH Terms: Abortion, Veterinary/blood*; Animals; Bottle-Nosed Dolphin/blood; Bottle-Nosed Dolphin/physiology*; Female; Parturition/physiology; Pregnancy; Pregnancy Outcome/veterinary; Pregnancy, Animal*/blood; Pregnancy, Animal*/physiology; Relaxin/blood*; Stillbirth/veterinary*