Fetus

About: Fetus is a research topic. Over the lifetime, 21567 publications have been published within this topic receiving 646380 citations. The topic is also known as: foetus & fœtus.

Relationship between arterial and venous Doppler and perinatal outcome in fetal growth restriction.

Abstract: Objective The aim of this investigation was to assess the relationship between abnormal arterial and venous Doppler findings and perinatal outcome in fetuses with intrauterine growth restriction (IUGR). Methods Doppler velocimetry of the umbilical artery (UA), middle cerebral artery (MCA), inferior vena cava (IVC), ductus venosus (DV) and free umbilical vein was performed in 121 IUGR fetuses with a UA pulsatility index (PI) > 2SD above the gestational age mean and subsequent birth weight 2SD below the gestational age mean (= ‘brain sparing’) in addition to abnormal UA-PI (n = 29, 24.0%), 3 = DV or IVC peak velocity index (PVIV) > 2SD above the gestational age mean and/or pulsatile UV flow (n = 50, 41.3%). Z-scores (delta indices) were calculated for Doppler indices. Perinatal mortality, respiratory distress (RDS), bronchopulmonary dysplasia (BPD), intraventricular hemorrhage (IVH), necrotizing enterocolitis (NEC), circulatory failure and umbilical artery blood gases were recorded. Results Absence or reversal of umbilical artery end-diastolic flow was observed in 4 (9.5%) of fetuses in group 1, 10 (34.5%) fetuses in group 2 and 41 (82%) fetuses in group 3. A low middle cerebral artery pulsatility index was found in 39 (78%) fetuses in group 3. Multiple regression analysis with gestational age at delivery, delta indices and cord artery blood gas as independent parameters and individual perinatal outcomes as dependent variables was performed. In this analysis the association was strongest with gestational age for each complication. There were no significant differences in Apgar scores between groups. At delivery, ‘brain sparing’ was associated with hypoxemia and abnormal venous flows with acidemia. Perinatal mortality was highest in group 3 and stillbirth was only observed when venous flow was abnormal. All postpartum complications were more frequent in fetuses with abnormal venous flows. The only statistically significant relation between Doppler indices and outcome was the association between abnormal ductus venosus flow and fetal death (r2 = 0.24, P < 0.05). Conclusion Growth restricted fetuses with abnormal venous flow have worse perinatal outcome compared to those where flow abnormality is confined to the umbilical or middle cerebral artery. In fetuses with low middle cerebral artery pulsatility, venous Doppler allows detection of further deterioration. While abnormal venous flows can be significantly associated with fetal demise, gestational age at delivery significantly impacts on all short-term outcomes. Copyright © 2000 International Society of Ultrasound in Obstetrics and Gynecology

Intrauterine death and circulating anticoagulant ("antithromboplastin").

Abstract: A report is presented of a young, otherwise apparently healthy, woman who had had three pregnancies which for some unknown reason terminated in intrauterine death (macerated foetuses). During the third pregnancy a coagulation defect was diagnosed, which was characterized by prolonged coagulation times and prolonged one-stage prothrombin time. This defect disappeared after the end of the pregnancy, but returned during the fourth pregnancy. This time a circulating anticoagulant was found, which inhibited the action of thromboplastin. The values found for the various coagulation factors were normal. The anticoagulant titre rose during the pregnancy from 1/2 to 1/10. Leucocyte agglutinating as well as Iymphocytotoxic antibodies directed against the husband's cells were demonstrated in the patient during the pregnancy. In this case, by passage of cell fragments and thromboplastic substances to the mother, the foetus had probably induced the development of antibodies against the foetal tissues. The foetus may be regarded as an incompatible transplant. The fourth pregnancy was terminated by caesarean section in the 34th week. The child weighed 1440 g and, after three exchanges of blood, did very well. The placenta was severely infarcted. It is postulated that the development of antithromboplastin during pregnancy may be a contributory cause of intrauterine death.

Why do newborn infants have a high plasma creatinine

Abstract: Background. Plasma creatinine (Pcr) levels at birth are greatly elevated in relation to the size (and the muscle mass) of the newborn infant and remain so for 1 to 2 weeks. Particularly intriguing is the fact that Pcr levels are higher in preterm than in term infants and for a longer postnatal period. The smaller the birth weight, the higher the Pcr. This cannot be explained by maternal transfer of Pcr or by the absolute and relative (to adult body surface area) reduced glomerular filtration rate of the newborn. Perhaps the renal handling of creatinine is involved. Design. In 522 pairs of mothers and fetuses, maternal and fetal Pcr were compared from 16 weeks of gestation until term. Pcr was measured in 66 newborns of various birth weights and followed for 1 month. Creatinine clearance (Ccr) and inulin clearance (Cin) were measured simultaneously in adult ( n = 8) and newborn ( n = 20) New Zealand White rabbits. In the latter, nephrogenesis continues after birth and they are therefore a good animal model for the study of the renal function in premature infants. Patient. A case of a premature male infant is presented (gestation: 29 weeks; birth weight: 1410 g) suspected of having sepsis because of premature rupture of membranes and postpartum maternal fever. This suspicion was not confirmed. Blood chemistry evaluation showed a high Pcr at birth (0.85 mg/dL, 75 μmol/L), even higher than that of the mother (0.77 mg/dL, 68 μmol/L). The Pcr started to decrease after ∼1 week but remained elevated throughout 1 month of follow-up. Results. From the maternal-fetal Pcr measurements it was quite evident that during the second half of gestation the small molecular weight creatinine (113 dalton, 0.3 nm radius) of the mother and fetus equilibrates at all maternal Pcr levels. The newborn Pcr levels were not only high at the time of birth but remained so for more than 3 weeks. It was also shown that the smaller the infant the higher the Pcr levels. The results of the animal experimental data showed that adult rabbits had the normal physiologic pattern in which Ccr overestimates Cin (Ccr/Cin ratio >1.0). In contrast, the results in the newborn rabbits showed an unexpected underestimation of the Ccr vis-a-vis Cin (Ccr/Cin ratio Conclusion. The riddle of the high Pcr levels in term and particularly in preterm newborns seems to be solved. Once the umbilical cord is severed, the perfect intrauterine maternal-fetal biochemical balance is disturbed. Thereafter, the already transferred exogenous, adult-level creatinine will rapidly disappear in the first urine specimens passed by the now autonomous newborn infant. A new steady state is achieved in due time, based on independent neonatal factors. One of these factors is the unusual occurrence of tubular creatinine reabsorption. We hypothesize that this latter temporary phenomenon is attributable to back-flow of creatinine across leaky immature tubular and vascular structures. With time, maturational renal changes will impose a barrier to creatinine. From that point onwards, total body muscle mass, glomerular filtration rate, and tubular secretion will in health determine the Pcr level of the individual. plasma creatinine, tubular handling of creatinine, newborn, premature infants.

Decreased levels of helper T cells: a possible cause of immunodeficiency in pregnancy.

Abstract: DECREASED maternal immune responsiveness during pregnancy may partly explain the survival of the fetus as an allograft. It may also account for changes in disease activity and antibody production i...