Maternal and fetal ultrasonography, vulvar temperature and vaginal mucous impedance for the prediction of parturition in Saanen does

Abstract

The aim of this study was to evaluate and correlate modifications of vaginal mucous impedance, vulvar temperature and ultrasonographic measurements (echobiometric parameters) to parturition in pregnant Saanen does. 30 does were selected for the study and submitted to an estrus synchronization protocol and natural mating. The females were evaluated daily from Day 143 of pregnancy to parturition. For the sonographic evaluations, the following structures were measured: biparietal diameter, thoracic diameter, abdominal diameter, ocular orbit, kidney length, kidney height, cardiac area, placentome length, cervical measurement and fetal heart rate; by means of two different approaches: transrectal and transabdominal, using a 7.5 MHz linear transducer. The vaginal mucous impedance was assessed using an electric estrous detector and vulvar temperature was measured using a non-contact infrared thermometer. Statistical analysis was performed using the R-project software and the significance level was set at 5% for all tests. 25 Saanen does became pregnant, resulting in 80.33% pregnancy rate. Fetal heart rate was negatively correlated to the hours to parturition (p<0,001; r-Pearson= -0,451), as well as vaginal temperature (p= 0,001; r-Pearson= -0,275), while cervical thickness was positively correlated to hours to parturition (p<0,001; r-Pearson= 0,490). The echobiometric parameters (biparietal diameter, thoracic diameter, abdominal diameter, ocular orbit, kidney length and height, cardiac area, placentome length), as well as vaginal mucous impedance did not vary throughout the timepoints of evaluation and did not correlate to the moment of parturition. It was concluded that the parameters of fetal heartbeat, vaginal temperature and cervical effacement in the last week of pregnancy provide valuable information regarding the proximity of parturition.

Deep Learning Model Using Continuous Skin Temperature Data Predicts Labor Onset

“…Observed Change (T) Time Window Measurement and Frequency lion 35 -1.3 C "late gestation" intraperitoneal, ~ continuous squirrel 21 -1.2 C -20 days intraperitoneal, 1/min orca whale 36 -0.3 C, -0.8 C -5 days, -24 hours rectal, 1/day wolverine 37 -0.8 C -24 hours intraperitoneal, 1 & 15 min rabbit 38 -0.7 C < -24 hours intraperitoneal, 1 & 6 min rat 39, 40 ~-0.5 C -5 to -1 days intraperitoneal horse 41 -0.5 c (-0.1) (-24) -15 to -3 hours rectal, 2/day sheep 42 -0.5 c -24 hours neck and vulvar, 1 & 10 min cow 8,9, 43 -0.3--0.2 C -2.5 to 0 days intravaginal; or ruminal dog 44 ≤ -0.3 C -24 hours intravaginal, daily means. Moose 45 ≤ -0.2 C -3 to 0 days ingested logger, 1 & 5 min mouse 46 <0.5 C -72 h to -24 h intraperitoneal, 1/min goat 10 not reported n/a vulva, 1/day macaque 47 not reported -1 to -1.5 hours subscapular, 1/min Despite the reliability of these observations across phases of reproductive life and across species, the use of body temperature for predicting human labor onset has not been robustly studied. Presently, human parturition is estimated to occur within a range of weeks around a population mean of 40.0 weeks from the last menstrual period (an estimated 38 weeks post-conception), or via ultrasound performed in the first trimester which provides the gestational age of the embryo.…”

“…Body temperature reflects female mammalian reproductive status from adolescence 1 through adult fertility [2][3][4] and menopause. 3,5 Body temperature monitoring is also of increasing interest in human pregnancy, 6 as temperature change predicts parturition in a variety of species [7][8][9][10] (Table 1). Historically, temperature measurements were most frequently taken from the "core", requiring probes inside the body.…”