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Results for “Fetal Viability”

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At least 19 recordsLinked to original sources
PubMed1992

Fetal viability and fetal growth after prolonged uterine contractions induced by progesterone withdrawal in late pregnancy in rats.

The hypothesis that sustained uterine contractile activity is the direct cause of fetal death after progesterone withdrawal in late pregnancy in rats was investigated. Pregnant rats were subjected to progesterone withdrawal on day 15 of pregnancy by injecting 2 mg mifepristone (RU 486) kg-1 or by ovariectomy with oestradiol replacement (200 ng day-1). Uterine contractile activity (force and frequency) at 4 h, but not at 2 h, in rats injected with mifepristone was significantly higher than in rats injected with vehicle. The contractile activity in mifepristone-treated rats remained higher than in control rats, at 12, 24 and 48 h. Fetal viability 36 h after mifepristone injection, when uterine contractions had lasted for 32 h, was not significantly different from fetal viability in rats injected with vehicle, but at 42 h after mifepristone injection, fetal viability was significantly reduced. In ovariectomized rats, uterine contractile activity at 12, 24, 36 and 48 h, but not at 8 h, was significantly greater than in ovariectomized rats with progesterone replacement (4 mg day-1). Fetal viability at 42 h after the operation, when uterine contractions had lasted for 30 h, was not significantly reduced, but it was significantly reduced at 48 h. When ovariectomized rats had been left to develop uterine contractions for a period before progesterone was injected, deprivation of progesterone and prolonged uterine contractions for about 30 h did not reduce fetal viability or fetal growth determined on day 18, but it did so 3 days later, on day 21. Administration of 5 mg isoxuprine kg-1 twice a day, which suppressed uterine contractions, improved fetal viability in ovariectomized rats at the earlier stage, but not at the later stage. Nevertheless, isoxuprine did improve fetal growth at the later stage in these ovariectomized rats. It is concluded that increased uterine contractile activity sustained for 32 h or less does not reduce fetal viability, but longer periods of contraction may be the cause of fetal death.

Animals↗
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↗
PubMed1989

Cadmium exposure on day 12 of gestation in the Wistar rat: distribution, uteroplacental blood flow, and fetal viability.

The effects of cadmium exposure (40 mumole CdCl2/kg, s.c.) on day 12 of gestation were evaluated in the Wistar rat. At 16-18 hours following such cadmium exposure, blood flow (as determined by radiolabeled microspheres) to the chorioallantoic placenta (CAP) was significantly reduced by 35%; at 24-26 hours, blood flow to the CAP had returned to control levels and was still unaffected at 38-43 hours. Uterine blood flow was not significantly altered at any of these timepoints. Between 16-18 and 24-26 hours after cadmium exposure, the concentration of cadmium in the placenta decreased significantly, while total cadmium content did not change. By 38-43 hours after cadmium exposure, total cadmium content of the placenta had increased significantly, although cadmium concentration was unchanged. There were no adverse effects on fetal viability or growth, as determined on day 20 of gestation. In sharp contrast, near-term (day 18) exposure to 40 or 50 mumole CdCl2/kg (s.c.) resulted in 53% and 82% mean incidences of fetolethality, respectively, within 24 hours. Administration of 50 mumole CdCl2/kg (sc) on day 12 also had no effect on fetal growth but resulted in increased fetolethality (12%). Thus midgestational cadmium exposure and its accompanying alterations in placental blood flow do not compromise fetal viability or growth. The differential response to cadmium at mid- and late gestation, in terms of fetolethality, is not due to maternal cadmium dose.

Animals↗
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↗
PubMed1989

Effect of surgical manipulation, placental fluid, and flunixin meglumine on fetal viability and prostaglandin F2 alpha release in the gravid uterus of mares.

Twenty-one pregnant mares with single or twin conceptuses between 41 and 65 days of gestational age were allotted to 5 treatment groups. A ventral median celiotomy was performed in all mares. In group-1 mares (3 mares, single conceptus), the uterus and fetus were palpated for 5 minutes. In group-2 mares (3 mares, single conceptus, flunixin meglumine), 250 ml of sterile placental fluid was injected into the nongravid uterine horn. In group-3 mares (4 mares, unicornuate twin conceptuses), group-4 mares (3 mares, unicornuate twin conceptuses, flunixin meglumine), and group-5 mares (8 mares, bicornuate twin conceptuses, flunixin meglumine), 1 conceptus was removed from the uterus via hysterotomy. All mares received progesterone prophylactically until day 100 of gestation or until the fetus died. The 3 mares in group 1 delivered clinically normal, live foals. The mean prostaglandin F2 alpha metabolite (PGFM) plasma concentration peaked at 180 +/- 5.2 pg/ml during uterine manipulation and fetal palpation, then declined to baseline by 1 hour. Free placental fluid (group 2) undermined the chorioallantois ventrally and resulted in fetal death within 3 hours after surgery. The mean PGFM plasma concentration peaked at 39 +/- 4 pg/ml following injection of placental fluid. None of the remaining fetuses in the 7 mares with unicornuate twin conceptuses (groups 3 and 4) survived. Five mares with unicornuate twin conceptuses (group 5) delivered single viable foals. In another mare in group 5, the fetus was alive 4 days after surgery, when the mare was euthanatized for a fractured femur.(ABSTRACT TRUNCATED AT 250 WORDS)

Abortion, Induced↗
PubMed1990

Can pregnancy-associated plasma protein A (PAPP-A) predict the outcome of pregnancy in women with threatened abortion and confirmed fetal viability?

Depressed pregnancy-associated plasma protein A (PAPP-A) concentrations have been found in patients with threatened abortion, often weeks before spontaneous abortion while the fetus was still alive. In order to extend these findings we have developed a highly sensitive PAPP-A radio-immunoassay and have established a reference range in early pregnancy for PAPP-A between week 7 and week 20 of pregnancy, based on blood samples from 240 pregnant women. The gestational age was determined by ultrasound. PAPP-A was measured in 128 women admitted to hospital because of vaginal bleeding in the 7th to 20th gestational week. The viability of the fetus was confirmed by ultrasonography. The serum values of PAPP-A were significantly lower (p = 0.002) in the group of women with vaginal bleeding than in the group of normally pregnant women. However, with regard to abortion later on, the predictive value of an abnormal blood test on admission was only 18.7%. Serial determinations showed increased PAPP-A values corresponding to the centile expected in the 12 women who aborted, as well as in the 116 women who gave birth. Consequently, the test is of no clinical value in the assessment of the prognosis in patients with symptoms of threatened abortion.

Abortion, Threatened↗
PubMed1992

Fetal viability does not affect the onset of stretch-induced labor and the increase in amniotic fluid prostaglandin F2 alpha and plasma prostaglandin F2 alpha metabolite levels.

The role of the fetus in the onset and progress of stretch-induced labor and in the change in amniotic fluid prostaglandin F2 alpha and plasma prostaglandin F2 alpha metabolite levels was evaluated in six normal pregnant women (group 1) and six women whose fetuses had been dead for more than one week (group 2). The uterus was distended by a balloon inflated with physiologic saline. Regular uterine contractions occurred, and increased in all patients. Within 21 hours, all patients delivered a normal baby in group 1 and a macerated fetus in group 2. There was no significant difference in induction-delivery interval between the two groups. Both groups showed a significant and similar range of increases in the levels of amniotic fluid prostaglandin F2 alpha and plasma prostaglandin F2 alpha metabolite during treatment (P less than 0.001). Thus, the fetus has no functional role in the onset and progress of stretch-induced labor or in the rise of amniotic fluid prostaglandin F2 alpha and plasma prostaglandin F2 alpha metabolite levels.

Adult↗
PubMed1990

[Rate of spontaneous abortion in relation to the time of fetal viability assessment].

For the first time, the rate of spontaneous abortion is reported in a multicenter study of three different gynecological centers. In 1987 und 1988, the average spontaneous abortion rate in 315 pregnancies was 3.3%, after foetal heart actions had been verified by ultrasonic examination between the 7th and 12th week of gestation. A statistical significance has been calculated between the spontaneous abortion rate of 6.3%, if foetal heart beats were seen between the 7th and 9th week, and the spontaneous abortion rate of 1.0% with an evidence of foetal life (p less than 0.01) between the 10th to 12th week of gestation. The rate of spontaneous abortion of women above 34 years of age (8.9%) is statistically different (p less than 0.01) to that of women under 35 (1.9%). In women older than 34, the spontaneous abortion rate before the 10th week of gestation is 22.2% in contrast to 3.2% of women younger than 35 (p less than 0.01). Considering the evidence of foetal heart actions between the 10th and 12th week, the spontaneous abortion rate of women above the age of 34 is 1.9%, compared to 0.8% of women younger than 35. The statistical higher spontaneous abortion rate of women above the age of 34 before the 10th week of gestation and the lack of statistical difference of the abortion rate in this defined age group for foetal life to be proven from the 10th week on, should be an argument in favour of the 10th week of gestation as the earliest date of prenatal diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Abortion, Spontaneous↗