Determination of Fetal Age by Ultrasonography in St. Kitts Green Monkeys

Abstract

Ultrasound assessments of fetal growth have been used in other species of primates to estimate fetal age, but there are no published morphometrics for the St. Kitts green monkey (Chlorocebus sabaeus), a species that has been important for studies of transplantation of fetal tissue into the brain as potential treatment for degenerative disease. Previous studies with other primate species have used relatively small numbers of pregnancies, measured repeatedly, to derive regressions for predicting fetal age from ultrasound studies. The present study derives data from 967 pregnancies, collected over a 9-year period, for predicting fetal age from ultrasound measurements of crown rump length, biparietal diameter, head circumference, abdominal circumference, and femur length in the St. Kitts green monkey. Linear and polynomial regressions were determined from pregnancies dated from a 3- to 4-day breeding period and confirmed in a second, independent group of pregnant monkeys with more extended breeding times to determine their accuracy for predicting fetal age. Although similar to morphometrics reported in other monkey species, there were some significant differences. These data will improve the estimates of fetal ages in previously published studies of St. Kitts green monkeys and provide more precise estimates of fetal age in studies of fetal development, genomics, and reproductive toxicology.

Parkinsonian monkeys with prior levodopa‐induced dyskinesias followed by fetal dopamine precursor grafts do not display graft‐induced dyskinesias

“…These measurements were confirmed by direct measurement after hysterotomy. The embryonic age was estimated based on data from almost 1,000 pregnancies studied at the St. Kitts Biomedical Research Foundation (Redmond and Evans, ). The fetus was removed via hysterotomy under pentobarbital anesthesia.…”

Coordinated expression of dopamine transporter and vesicular monoamine transporter in the primate striatum during development

“…The gestational age of fetal monkeys was determined by ultrasonography (Morrow et al, ). The gestation period in this species is ∼165 days (Redmond and Evans, ). Fetuses were removed by hysterotomy under deep anesthesia.…”

Application of ultrasonographic human estimated foetal weight formulas to cynomolgus monkeys (Macaca fascicularis) at 129–132 days of gestation: A comparative study of estimated and actual birthweight

“…In veterinary medicine, USG has also been applied to various animal species (Kähn, 1992 ), such as dogs (Khatti et al., 2017 ; Lopate, 2008 ), horses (Ortega‐Ferrusola et al., 2022 ; Reef et al., 1996 ) and non‐human primates (Conrad et al., 1995 ; D'Mello et al., 2023 ; Jang et al., 2023 ; Jaquish et al., 1995 ; Lee et al . ; Morgan et al., 1987 ; Oerke et al., 1996 ; Redmond & Evans, 2012 ; Tarantal, 1990 ; Tarantal & Hendrickx, 1988a , 1988b, 1988c, 1988d; VandeVoort & Tarantal, 1991 ) (Table 1 ), for reproductive management and research, including monitoring foetal development. Currently, there is no information about the foetal weight in non‐human primates, except only one study in the baboon (Van Calsteren et al., 2009 ).…”