title: The detection and monitoring of early pregnancy in the vervet monkey (Cercopithecus aethiops) with the use of ultrasound and correlation with reproductive steroid hormones.
abstract: Twenty early pregnancies were diagnosed and monitored in vervet monkeys by ultrasonography. Non-gravid uteri became increasingly echogenic from cycle days 7 to 26. The first definite sign of pregnancy was a gestational cavity of 2 mm (+/- 0.80) at 33.0 (+/- 1.48) days menstrual age, which was also used to date all subsequent features. Earlier signs, such as an endometrial line swelling or endometrial 'pregnancy' ring, as reported for other non-human primate species, could not be reliably and consistently used to diagnose pregnancy in vervet monkeys. A rapid increase of the gestational cavity size from days 37 to 49 corresponded closely to a rapid increase in plasma progesterone concentration from day 39 to 49. The first yolk sac was recognizable at 38.0 days (+/- 3.10) and measured 3.3 mm (+/- 0.40) in diameter. A heart beat could be detected at 45.5 (+/- 1.73) days and the size of the first measurable embryo at 35 days was 2 mm. The dating of most features was within the range reported for other non-human primate species.
authors.affiliation: Primate Unit, Experimental Biology Programme/MRC, Tygerberg, South Africa. jurgen.seier@mrc.ac.za
authors.forename: J V
authors.initials: JV
authors.lastname: Seier
authors.forename: G
authors.initials: G
authors.lastname: van der Horst
authors.forename: M
authors.initials: M
authors.lastname: de Kock
authors.forename: K
authors.initials: K
authors.lastname: Chwalisz
mesh_terms: D000818:Animals; D002522:Chlorocebus aethiops; D004717:Endometrium / Q000000981:diagnostic imaging / Q000502:physiology; D005260:Female; D008991:Monitoring, Physiologic / Q000379:methods / Q000662:veterinary; D009215:Myometrium / Q000000981:diagnostic imaging / Q000502:physiology; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000502:physiology*; D016216:Ultrasonography, Prenatal / Q000379:methods / Q000662:veterinary*