PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Fetal Viability”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1977

Accuracy of real-time sonography in the determination of fetal viability.

After 8 weeks of fetal age, real-time ultrasonography is a simple, rapid, and highly reliable technic for differentiating a viable from a dead fetus. Fetal movements are invariably detected after 8 weeks of fetal life, and a discrete, fluid-filled, intrathoracic pulsating heart can be seen after 11-12 weeks of fetal life. Absence of these findings, as observed by two independent examiners each viewing the fetus for 3 minutes with real-time sonography, provides reliable evidence of fetal demise. A prospective evaluation of 390 consecutive fetuses yielded only one false positive diagnosis of fetal viability. No living fetus was diagnosed as being dead.

Female↗
PubMed1976

Use of an ultrasonic blood flow monitor for determining fetal viability in the rhesus monkey (Macaca mulatta). A preliminary study.

Ultrasonic stethoscopy proved to be a reliable and convenient technique for determing fetal viability in Macaca mulatta. Examinations, begun at day 150 of gestation in 33 monkeys and between days 32 and 58 in four other animals, were repeated at intervals of one to seven days. The earliest time of detecting blood flow in the fetal placenta was 42 days of gestation, fetal heart sounds geing discerned later. Three types of fetal cardiac rhythms were recognized: (1) a constant rate during most of pregnancy, (2) fluctuations associated with uterine contractions during labor, and (3) sudden transient bradycardia during violent rotations of the cephalically presented fetus.

Animals↗
PubMed1978

Real-time sonography in obstetrics.

Three hundred fifty real-time scans were performed on pregnant women for various indications. Placental localization was satisfactorily obtained in 173 of 174 studies. Estimates of fetal gestation from directly measured biparietal diameter were +/-2 weeks of actual gestation in 153 of 172 (88.9%) measurements. The presence or absence of fetal motion and cardiac activity established a diagnosis of fetal viability or fetal death in 32 patients after the first trimester. Accurate diagnosis was made in 52 of 57 patients with threatened abortions, and two of these errors occurred in scans performed before completion of the eighth postmenstrual week. Because of the ability to demonstrate fetal motion, real-time sonography should have many applications in obstetrics.

Abortion, Threatened↗
PubMed1976

Ultrasonic diagnosis of intrauterine fetal death.

When there is doubt concerning fetal viability, the confirmation or exclusion of fetal death assumes major importance in the management of pregnancy. Frequently the clinical diagnosis is uncertain and recourse must be had to ancillary investigation. Radiologic methods may confirm the clinical suspicion of intrauterine fetal death in many cases, but these are accompanied by the hazard of irradiation. Ultrasound can provide valuable information regarding fetal viability. Ultrasonic signs of fetal death are discussed in the light of the literature and our own experience, with emphasis on the value of the M-mode in detecting fetal heart pulsations.

Female↗
PubMed1977

The diagnosis of fetal hydrocephalus before viability.

A diagnosis of fetal hydrocephalus was made before viability. The diagnosis was indicated by a discrepancy between the sonographic fetal head size, the uterine size by both clinical and sonographic examination, and x-ray films. An abortion was performed by hysterotomy.

Adolescent↗
PubMed1979

Prolongation of gestation in the rat and hamster by naproxen.

Administration of naproxen by once or twice daily subcutaneous injection, or orally in the drinking water, was found not to routinely prevent parturition in either the rat or the hamster. However, the duration of labor was prolonged and associated with poor pup viability. The prolonged labor and fetal mortality were thought to be due to suppression of myometrial activity after onset of labor and caused by the episodic administration regimens. Thus fetal deaths could result from asphysia due to suppression of uterine contractions, after partial or total placental separation had occurred. Naproxen was, therefore, administered on a more continuous basis by subcutaneous implantation of pellets in rat and hamster, or orally every four hours in the rat. Either of these regimens was then able to postpone parturition beyond the range of deliveries in control animals. In such naproxen treated rats there was no sign of placetal detachment, even out to day 25 of pregnancy. Fetal viability was preserved and fetuses continued to gain weight. These observations are consistent with a true prolongation of gestation by naproxen rather than merely an interference with the process of labor.

Administration, Oral↗
PubMed1977

Effect on pregnancy and plasma progesterone of exogenous steroid maintenance in ovariectomised pregnant rabbits.

Pregnancy was maintained in ovariectomised does with 1 to 4 mg/day of exogenous progesterone with or without 0.2 microgram/day of estradiol. Progesterone doses were designed to give similar plasma progesterone levels in treated groups to those found in normal pregnancy, and were measured and compared with normals since this comparison does not appear to have been published previously. In normal pregnancy mean progesterone levels reached 10 ng/ml on day 7 and then plateaued at 14 ng/ml between day 10 and 20 before falling to very low levels at parturition. In treated groups progesterone levels reached 10 ng/ml on day 6 and remained between 10 and 13 ng/ml until day 20 before declining. The difference between treated and control plasma progesterone plateau levels was tested using the t-test and was found not be significant. The differences in progesterone levels between treated groups with or without estradiol, whether pregnant or not, were also not significant. Mean litter sizes (alive or dead) were not significantly different. However, fetal viability in the group maintained on progesterone alone was significantly lower than in the normal controls.

Animals↗
PubMed1979

Postpartum survival of mice exposed in utero to ultrasound.

We found no credible enhancement of neonatal mortality in mice exposed in utero on Day 8 of gestation to ultrasound at 0.44 W/cm2 (+/- 20%) spatial average intensity, 2 MHz, continuous wave, for 60--180 s in a 37 degrees C water bath. This result is compared with the adverse effect on neonatal survival reported by Curto [in Ultrasound in Medicine (Plenum, New York, 1976), Vol. 2, pp. 535--536] for exposure on Day 14 of gestation at about 0.125 to 0.5 W/cm2, 1MHz, continuous wave, for 180 s in a 30 degrees C bath. It is concluded that a temporary reduction in fetal viability, lasting from 4 days to less than 10 days after exposure, could account for both sets of data. It is also evident from these data that improved methods of determining intensities within mammalian tissues are highly desirable.

Animals↗
PubMed1978

Comparison of oestriol in mother and fetus during labour and in the baby at birth.

The progressive rise in pregnancy of oestriol values and their significance in assessing fetal viability is well known, although the exact function of this increase is not understood. In considering the problem it was thought that further information of oestriol levels in mother, fetus and newborn could prove of value. The mean cord plasma oestriol was lower in small-for-dates than in normal cases, but in both groups it was ten times higher than in the relative maternal peripheral veins. In pooled capillary fetal scalp samples the mean oestriol was slightly higher in normal compared with small-for-dates cases. The use of gas chromatography--mass spectrometry was investigated and shown to give an accurate measurement of plasma oestriol levels. The expense of this procedure may be offset by its ability to determine simultaneously the nature and amount of other steroids present.

Birth Weight↗
PubMed1977

The incompetent cervix and accelerated fetal lung maturation.

The incompetent cervix is an infrequent but identifiable cause of late midtrimester pregnancy loss. The early diagnosis and surgical treatment of these patients have resulted in successful outcomes in 70 to 80 per cent of patients treated. However, this closure of the cervix may be only partially successful, in that the pregnancy may continue beyond the age of fetal viability, but the fetus may be born prematurely. There are no reports in the literature of the neonatal respiratory status of these infants delivered between 24 and 33 weeks of gestation. Nineteen preterm infants of less than 3-4 weeks' gestation were born to mothers with an incompetent cervix. The incidence of the respiratory distress syndrome was significantly less in infants of mothers with an incompetent cervix than in control infants of similar gestation (p less than 0.001). The incomplete cervix appears to be related to maternal or fetal conditions which result in accelerated fetal lung maturation.

Female↗
PubMed1976

In vivo and in vitro studies of 15alpha-hydroxyprogesterone in the human placenta.

Studies were conducted to determine the fate of 15alpha-hydroxyprogesterone in human placental tissue. Tritiated 15alpha-hydroxyprogesterone was perfused through normal human placentas in situ at the time of Cesarean section and incubated with a 10,000x g microsomal supernate of the placenta in vitro. In both systems the substrate, but no additional metabolites were identified. These findings indicate that 15alpha-hydroxyprogesterone is not metabolized during its passage in the human term placenta, and suggests that because of its fetal origin clinical measurements of 15alpha-hydroxyprogesterone may provide a valuable index to the status of fetal viability.

Crystallization↗
PubMed1975

Teratology studies of a mixture of tallow alkyl ethoxylate and linear alkylbenzene sulfonate in rats and rabbits.

A mixture of 55% tallow alkyl ethoxylate sulfate (TAE3S) and 45% of linear alkylbenzene sulfonate (LAS) was fed to two generations of rats at dietary levels of 0.1, 0.5 or 1.0%. The rats were fed the surfactant mixture either continuously or during the organogenesis (days 6-15) period of six pregnancies. In addition, pregnant New Zealand rabbits were given 50, 100 or 300 mg/kg doses of the surfactant mixture by intubation on days 2-16 of gestation during a single pregnancy. No adverse effects were noted on conception, fetal viability or post-natal survival in either generation of rats. There were no statistical differences among the groups of rat fetuses taken by Caesarian section and examined for birth defects. Of 1210 rat fetuses, the overall incidence of abnormal young was 9.0%. Similarly, no adverse effects were seen in rabbits treated with the surfactant mixture. Of 855 rabbit fetuses, 5.7% were abnormal, but the incidences of defective fetuses in the test groups were not significantly different from those in controls. Thus, no test related effects were seen on reproduction or embryonic development in either animal species.

Abnormalities, Drug-Induced↗