Ultrasonographic analysis of fetal gastrointestinal motility during the peripartum period in the dog.

The aim of this study was to investigate fetal gastrointestinal motility (FGM) of dogs using ultrasonic imaging and its association with vaginal and rectal temperature, serum progesterone concentrations and fetal heart rate. Pregnant bitches were examined after day 54 of gestation and there were determinations of vaginal and rectal temperature and serum progesterone concentrations. The fetal abdomen was evaluated for 30 s using longitudinal and transversal assessments, and FGM was scored as 0 (no peristalsis) or 1 (evident peristalsis). Number of fetuses with a 1 or 0 score were determined for each bitch (number and the percentage of fetuses with FGM). A total of 135 FGM measurements were recorded. There was FGM in 0/3, 0/6, 1/6 (16.7 %), 3/20 (15 %), 5/18 (27.3 %), 18/28 (64.3 %), 12/17 (70.6 %), 14/22 (63.6 %), 6/9 (66.7 %), 4/6 (66.7 %) fetuses from day -9 until 0 preceding parturition, respectively. In the last 5 days before parturition, 63.3 % of fetuses had FGM. Vaginal and rectal temperature were strongly and positively correlated (P < 0.001). Vaginal temperature was positively correlated with progesterone concentrations and fetal heart rate (P < 0.01), and there was a small negative correlation with FGM (r = -0.331, P < 0.05). Due to ease of data collection, the assessment of FGM is a valuable procedure for evaluation of fetal maturity in dogs. Vaginal and rectal temperatures are reliable variables to be assessed during the last week of pregnancy for estimating the time of parturition.

Maternal and fetal arterial blood gas data in normotensive, singleton, isoflurane anesthetized sheep at 124-126 days of gestation.

The aim of this case series was to describe the differences between maternal and fetal blood-gas results during anesthesia. Sixteen singleton adult merino ewes weighing 60.1 ± 5.1 kg at 125.7 d (124 to 126 d) gestation were anesthetized. Maternal (radial) and fetal (umbilical) arterial blood gas samples were collected 79 ± 6 min after the start of anesthesia if maternal mean arterial pressure (MAP) was stable and > 65 mmHg. Fetal pH, partial arterial pressure of oxygen (PaO2), glucose, arterial hemoglobin oxygen saturation (SaO2), sodium, and chloride were significantly lower and fetal partial arterial pressure of carbon dioxide (PaCO2), lactate, hematocrit, total hemoglobin, potassium, and calcium were significantly higher than maternal blood-gas values. Fetal pH, PaO2, and BE were lower and fetal lactate was higher than fetal umbilical arterial samples previously reported, which may indicate a non-reassuring fetal status. Further refinement of the ovine experimental model is warranted with fetal monitoring during maternal anesthesia.

L'objectif de l'étude était de décrire les différences dans les résultats d'analyse des gaz sanguins maternel et foetal durant l'anesthésie. Seize brebis mérinos primipares pesant 60,1 ± 5,1 kg à 125,7 j (124 à 126 j) de gestation ont été anesthésiées. Des échantillons de sang artériel maternel (radiale) et foetal (ombilicale) ont été prélevés 79 ± 6 min après le début de l'anesthésie si la pression artérielle moyenne (PAM) maternelle était stable et > 65 mmHg. Pour le sang foetal, les valeurs de pH, de la pression artérielle partielle en oxygène (PaO2), du glucose, de la saturation en oxygène de l'hémoglobine artérielle (SaO2), du sodium, et du chlorure étaient significativement inférieures, et les valeurs de la pression artérielle partielle en dioxyde de carbone (PaCO2), du lactate, de l'hématocrite, de l'hémoglobine totale, du potassium, et du calcium étaient significativement supérieures que celles du sang maternel. Les valeurs foetales du pH, de la PaO2, et de BE étaient plus basses et le lactate foetal étaient plus élevées que les valeurs d'échantillons provenant du sang artériel ombilical foetal rapportées précédemment, ce qui pourrait indiquer un statut foetal non-rassurant. Des améliorations de ce modèle expérimental ovin sont souhaitées avec un suivi foetal durant une anesthésie maternelle.(Traduit par Docteur Serge Messier).

Effectiveness of determining the parturition date in bitches using the ultrasonographic fetometry as compared to hormonal and cytological methods.

In clinical practice, the parturition date in bitches is calculated on the basis of the established ovulation date, using determination of the level of LH and P4. Additionally cytological examination of vaginal smears makes it possible to establish the onset of diestrus, from which the delivery occurs after about 57 days. The latest method used in bitches for this purpose is foetal biometry. Measurements of the inner chorionic cavity diameter (ICC) and biparietal diameter (BP) with formulas published by Luvoni and Grioni have been popularized and the most practically useful. In a group of six bitches the effectiveness obtained with the use of ICC was 66.67% with an accuracy of 1 day and 100% with an accuracy of 2 days. BP measurements gave better results, as the accuracy was respectively 83.33% and 100%. The effectiveness of predicting the delivery date on the base of method consisting in determining the LH surge was 66.67% with an accuracy of 1 day and 100% with an accuracy of 2 days. The best effectiveness was obtained while using the method based on P4 level determination (100% both with an accuracy of 1 day, as well as of 2 days). The lowest accuracy was obtained while using the cytological method. Generally, a comparison of the methods used for predicting the date of delivery in bitches confirms practical usefulness of fetometry. Its effectiveness was not lower than traditional methods used so far, while its advantage lies in the ease of performance and the long term of application during gestation. However, full confirmation of the practical usefulness of this method requires further research on a larger number of animals.

Telemetric monitoring of fetal blood pressure and heart rate in the freely moving pregnant sheep: a feasibility study.

Remote telemetric monitoring of fetal haemodynamics in pregnant sheep would allow unrestricted animal movement, minimize suffering and distress, and improve animal welfare, while enhancing the quality of data collected. This may also be useful in clinical practice following fetal surgery. Using an open fetal surgical technique at approximately two-thirds of gestation, we implanted the catheter of a D70-PCTP haemodynamic telemetric device (Data Sciences International, Tilburg, The Netherlands) into the carotid artery of the fetal sheep (n = 4). The attached transmitter was secured to the posterior aspect of the maternal anterior abdominal wall. Two receivers, with a range of 1 m each, were sited in an 11 m² sheep enclosure to maximize animal freedom while allowing continuous monitoring of the ewe. The receivers were connected by cable to a nearby computer. In the first two procedures, both fetuses died eight and 12 days after surgery, and the catheter tip was observed to be lying in the bicarotid trunk. In the next two procedures the catheter tip was threaded further upstream from the insertion point, in an attempt to reach the fetal aorta, and both fetuses survived until the scheduled postmortem examination at the end of pregnancy. After catheter implantation, fetal blood pressure (BP) and heart rate (HR) were successfully recorded continuously for seven days and then hourly per day for a further three weeks. The fetal BP and HR values were in the normal range for healthy sheep fetuses.

Blood gas analysis of bovine fetal capillary blood during stage II labor.

The aim of this study was to determine whether blood gas variables in fetal capillary blood during the last 30 min of stage II labor can be used to diagnose fetal asphyxia. Twenty-five newborn calves were used to investigate the correlation between capillary blood gas values obtained from the dorsolateral aspect of the distal pastern and those in arterial and venous blood. The pH, partial pressure of oxygen, partial pressure of carbon dioxide, concentration of bicarbonate, base excess and oxygen saturation were determined. The bicarbonate concentration (arterial, r=0.759; venous, r=0.766; both P<0.0001) and base excess (arterial, r=0.730; venous, r=0.807; both P<0.0001) had the highest correlations. Fetal capillary blood was collected during the last 30 min of stage II labor and the results of blood gas analysis were compared with those of arterial and venous blood collected immediately after birth in 38 calves. The pH (arterial, r=0.806; venous, r=0.885; both P<0.0001) and base excess (arterial, r=0.822; venous, r=0.871; both P<0.0001) had the highest correlations. The pH and base excess were significantly lower after birth than during the last 30 min of stage II labor. The severity of fetal acidosis during stage II labor can be easily and reliably determined using the pH or base excess of fetal capillary blood.

Hormonal measurements in late pregnancy and parturition in dairy cows--possible tools to monitor foetal well being.

Three dairy heifers (A, B and C) were induced to parturition with two prostaglandin (PG) F(2alpha) injections on day 268 and 269 of pregnancy. Signs of approaching parturition were carefully observed. The following parameters were registered: degrees of calving difficulty, date and time of parturition, calf's birth weight and calf's sex. Body temperature was measured and blood samples were taken every 3 h 3 days before the first PGF(2alpha) injection until 3 days after parturition. The plasma concentrations of the PGF(2alpha) metabolite, progesterone, cortisol, oestrone sulphate and pregnancy associated glycoproteins (PAGs) were analysed. Heifers A, B and C delivered 48, 51 and 57 h after the first PGF(2alpha) injection, respectively. Heifer A delivered without any signs of calving difficulty, whereas, the parturition was considered to be slight and moderate difficulty occurred in the delivery of heifers B and C, respectively. The calf of heifer C, without any abnormal gross-evidences, was stillborn. All animals had retained foetal membranes. A slight increase of the PGF(2alpha) metabolite at the time of parturition was found only in heifer C, whereas the levels dramatically increased in all animals 15-24 h after parturition. At the same time, progesterone levels decreased within 3 h after the first PGF(2alpha) injection (P < 0.05) and reached 0.8, 2.7 and 12.4 nmol/l at the time of parturition in heifers A, B and C, respectively. High release of cortisol at the time of parturition was seen in heifer C. Rising levels of oestrone sulphate around the time of parturition were recorded in all heifers, whereas, increasing levels of PAGs were recorded only in heifer A. In conclusion, the patterns of the PGF(2alpha) metabolite, cortisol, progesterone and PAGs were changed in the cases of calving difficulty and stillbirth after PGF(2alpha)-induction of parturition. However, the relationship between oestrone sulphate and PAGs and the status of foetal well being prior to parturition require further elucidation.

Transesophageal echocardiography in fetal sheep. A monitoring tool for open and fetoscopic cardiac procedures.

BACKGROUND: Cardiac procedures in exteriorized fetuses or assisted by fetoscopy require monitoring capabilities not attended by conventional maternal transabdominal echocardiography. METHODS: We, therefore, assessed the potential of fetal transesophageal echocardiography (TEE) utilizing an intravascular ultrasound catheter (IVUC) for fetal cardiac monitoring. We inserted a 10-F-10-MHz IVUC into the esophagus in 12 exteriorized fetal sheep and by a fetoscopic approach in 4 fetal sheep. Cardiac events were observed. Heart rate, cardiac rhythm, patency of the foramen ovale and ductus arteriosus, and the width of the branch pulmonary arteries could be assessed in all fetuses. Ventricular contractility could be assessed only in fetuses weighing less than 2.5 kg. Larger fetuses did not allow adequate imaging of the apical portion of the ventricles because of limited tissue penetration of the IVUC. Fetal TEE permitted placing small guide wires in the cardiac atria and left ventricle. Short-lived premature beats following intracardiac manipulations of these wires could be observed by fetal TEE in all cases. RESULTS: At autopsy, no complications from IVUC insertion were observed in the exteriorized fetuses. Fetoscopic placement of the IVUC resulted in minor perioral skin erosion in two nonexteriorized fetuses. CONCLUSIONS: In conclusion, fetal TEE can be achieved with minor fetal injury and may provide useful information during open and fetoscopic cardiac procedures. Further improvements in IVUC design will permit the application of this technique to monitor human fetal cardiac procedures.

Intrauterine endoscopic creation of urinary tract obstruction in the fetal lamb: a model for fetal surgery.

OBJECTIVE: Our purpose was to evaluate the feasibility of intrauterine endoscopic fetal surgery in a fetal lamb model by creating a urinary tract obstruction. STUDY DESIGN: Lower urinary tract obstruction was created by ligation of the urethra and urachus in 21 fetal lambs, eight at 95 to 105 days' gestation (term 145 days) and 13 at 70 to 75 days. The endoscopic approach consisted of a 0-degree 5 mm telescope, three 5 mm cannulas, uterine distention by amnioinfusion, and adapted instrumentation. Intrauterine fetal monitoring included temperature and pulse oximetry registration. RESULTS: In 20 cases the urachus could be identified and ligated inside the umbilical cord. The urethra was ligated in the anterior abdominal wall (n = 7) or obstructed at the level of the penis (n = 13). Mean fetal heart rate was 147 +/- 35 beats/min, and fetal temperature at the end of intervention was 38.14 degrees +/- 2.1 degrees C. The overall postoperative survival rate was 76%. CONCLUSION: Urinary tract obstruction can be created endoscopically in the fetal lamb. This operation can serve as a model for endoscopic fetal surgery.

Chronic instrumentation and longterm investigation in the fetal and maternal baboon: tether system, conditioning procedures and surgical techniques.

A tether system, conditioning procedures and surgical techniques were designed to maintain chronic catheters and electrodes in the pregnant baboon and her fetus. The tether system was comprised of a lightweight metal backpack containing catheters and electrodes, couplers, pressure transducers and electrical cabling. The backpack was held snugly in place by shoulder and body straps. A flexible metal tether connected the pack to a ball bearing assembly mounted on the top of the animal's home cage. Attached to the assembly were two infusion pumps, fluid reservoir and slip ring electrical connector. The entire system rotated freely with the movements of the animal; thus, the instrumentation and connectors were secure while access was maintained for continuous physiologic recording and intravascular infusion or intermittent blood sampling with minimal physical restraint. Animals were conditioned to accept the system prior to pregnancy and animals who demonstrated tolerance were bred. An initial group of 10 pregnant animals were sham tethered during pregnancy at 102 +/- 7 days with term gestation estimated at 180 days. Surgical procedures were done at 136 +/- 4 days with placement of catheters in the maternal femoral artery and vein, fetal carotid artery jugular vein and trachea, amniotic fluid cavity, and electrodes for fetal electrocardiogram and electroencephalogram. The mean fetal survival time was 9.3 (range 0 to 29) days. The major complications which led to early delivery were placental abruption and rupture of amniotic membranes. With ultrasonic localization of the placenta and determination of fetal position before surgery, these complications may be avoided.(ABSTRACT TRUNCATED AT 250 WORDS)

Ultrasonography as an adjunct to pregnancy assessments in the mare.

Ultrasonographic detection of pregnancy was performed in 952 Thoroughbred mares. Characteristic images were obtained between 12 and 55 days after breeding. Twins in the same uterine horn as well as twins in opposite horns were imaged, and for the first few months of gestation appeared similar to single pregnancies. Growth curves as a function of time were developed, utilizing horizontal diameters of the blastocysts versus breeding dates. Comparisons between horizontal and vertical diameters demonstrated no appreciable differences when observed as a group. Growth curves derived from twins did not differ significantly from those for single pregnancies during the period we observed them. Ultrasonographic evaluations were valuable in substantiating mechanical destruction of one of the twin blastocysts immediately following the maneuver. Uterine artifacts such as endometrial and lymphatic cysts also were visualized and portrayed. Although these structures represented a source of false-positive results, they usually could be properly identified on the basis of their morphometric and growth characteristics.

Intrauterine fetal demise associated with consumption coagulopathy in a Douc langur monkey (Pygathrix nemaeus nemaeus).

Intrauterine fetal demise was suspected in a Douc langur monkey based on measurements of declining urinary estrogen levels. Additional clinical evaluation by fetal cardiac auscultation, ultrasonic instrumentation, radiologic examination, and amniocentesis supported the diagnosis. Blood clotting studies demonstrated deficiency of factors consistent with a diagnosis of consumptive coagulopathy, a syndrome identical to that observed in man following prolonged intrauterine fetal demise.