Validation of gestational age by developing formulae and assessing embryonic and fetal development by ultrasonic fetometry in Bangladeshi crossbreed (Jamunapari × Black Bengal) goats

Abstract

The study was designed to estimate the gestational age (GA) and determine the appropriate parameters related to gestational stages in Jamunapari cross breed goats (Jamunapari × Black Bengal), conducted at Chattogram district, Bangladesh. For this purpose, six different gestational parameters [gestational sac diameter (GSD), gestational sac length (GSL), crown- rump length (CRL), trunk diameter (TD), bi-parietal diameter (BPD) and placentome diameter (PD)] were checked by ultrasonography at different stages of pregnancy. Goats (n = 150) were used for pregnancy diagnosis by trans-abdominal ultrasonography. Pregnancy was confirmed by the presence of amniotic fluid, fetal heartbeat, fetal ribs, femur, trunk etc. The gestational age was estimated statistically (EGA) and compared to actual GA (AGA). GSD, GSL, PD and CRL were significantly different between estimated and actual gestation age while PD did not vary significantly up to the second trimester of pregnancy. At early stage of pregnancy, GSD, GSL and CRL did not show significant variation between estimated and actual gestational age. PD and BPD in mid pregnancy while TD in late pregnancy were not significantly different between EGA and AGA. Significant relations were detected between actual pregnancy stage and certain parameters at different stages of pregnancy. The EGA, when calculated with a margin of ±1–5 days, did not significantly vary in estimating the expected date of delivery (EDD) across all measured parameters, except for TD when subtracting 1–5 days. The study concludes that GSD, GSL, and CRL are highly reliable for estimating gestational age in the first trimester; BPD, TD, and PD are reliable in the second trimester; and TD is most reliable in the third trimester. The EDD may vary by ±1–5 days when using the derived equations for all six parameters, but it may vary by ±4 days specifically when using TD measurements.