Increased pulsatility in the fetal ductus venosus is not related to altered cardiac strain in high-risk pregnancies.

Blood flow velocity patterns in fetal veins are considered to reflect cardiac function, but have not been convincingly documented. The aim of this study was to generate reference values for fetal cardiac strain and compare it with results in fetuses with signs of increased venous pulsatility

Doppler velocimetry for predicting fetal death in a twin pregnancy.

Diagnosis of discordant twins is easily accomplished with modern ultrasound equipment, though diagnosing twin-to-twin transfusion syndrome (TTS) at an early stage might be a problem. The possibility of excluding TTS by Doppler ultrasound is demonstrated in a case with early severe growth restriction of one fetus. Characteristic blood velocity changes in a dying fetus are also illustrated. The Doppler technique has become an accepted method in obstetrics for antenatal surveillance, permitting evaluation of fetal circulation in a non-invasive manner and providing important physiological information on the fetal condition. Absent end-diastolic flow in the umbilical artery (UA) can warrant operative delivery for fetal distress (1). Perinatal mortality is increased fivefold in multiple gestation, as compared with singleton pregnancy (2). The major complications include preterm labor, intrauterine growth retardation (IUGR), TTS, polyhydramnios, oligohydramnios, fetal malformations, and pre-eclampsia. Twin fetuses are generally smaller than singletons and IUGR and intrauterine fetal deaths are more common (3). Before the introduction of the Doppler technique, ultrasound-imaging evaluation of discordant fetal size in twin pregnancy was a problem. Differential diagnosis of TTS and a true growth retardation of one fetus was a frequent worry for the clinician. Doppler examination of the fetal venous circulation with pulsating flow in the umbilical vein has been found helpful in the diagnosis of fetal congestive heart failure (4, 5). The general ultrasound imaging and Doppler findings in TTS are listed in Fig. 1. The information provided by ultrasound imaging and Doppler can thus distinguish between TTS and growth retardation of one fetus and assist the clinician in making a diagnosis and predict the outcome. The following case illustrates characteristic blood velocity findings in a dying fetus

New score indicating placental vascular resistance.

Background. Umbilical artery Doppler velocimetry is a routine method for fetal surveillance in high-risk pregnancy. Uterine artery Doppler seems to give comparable information, but it can be difficult to interpret as there are two arteries, which might show notching and/or increased pulsatility index (PI) as signs of increased vascular impedance. Combining the information on vascular resistance on both sides in a new score might simplify and improve evaluation of placental circulation. Methods. Uterine and umbilical artery Doppler velocimetry was evaluated in 633 high-risk pregnancies. The managing clinician was informed only about the umbilical artery flow. The umbilical artery flow spectrum was semiquantitatively divided into four blood flow classes (BFC), expressing signs of increasing vascular resistance. The uterine artery Doppler flow spectrum was divided into five uterine artery scores (UAS), taking into account presence/absence of notching and/or increase in PI. By adding UAS to BFC, a new placental score (PLS) was constructed with values ranging from 0 to 7, indicating general placental vascular resistance. The scores were related to three outcome variables: small-for-gestational age (SGA), premature delivery (<37 weeks), and cesarean section. Results. All three score systems showed a significant relationship between signs of increasing vascular resistance and outcome. The new PLS showed the best association to adverse outcomes, with optimal cut-off at values exceeding score 3. Conclusion. Doppler velocimetry on both sides of the placenta showed a strong relationship to an adverse outcome of pregnancy. The new PLS showed a better relationship to adverse perinatal outcome than the BFC and the UAS. The PLS can simplify evaluation of uteroplacental and fetoplacental Doppler velocimetry

Tętniczy przepływ krwi w płucach i OUN płodu w ciąży o przebiegu prawidłowym i w ciąży wysokiego ryzyka

Studies on fetal lung/brain circulation by means of power Doppler technique have suggested a marked reduction in lung perfusion in high-risk pregnancies as a sign of circulation redistribution. The ratio between lung/brain perfusion might therefore give a new method to predict fetal circulation centralization. Objective: The aim of the present study was to obtain fetal lung and cerebral artery ratio in normal and high-risk pregnancies. Study design: Doppler samples from proximal right pulmonary artery blood velocities and middle cerebral artery (MCA) were recorded cross-sectionally in 228 normal singleton pregnancies at gestational age 22 to 40 weeks. MCA / right pulmonary artery pulsatility index (PI) ratio was calculated. Doppler samples from proximal right pulmonary artery and MCA were also recorded in 89 high-risk singleton pregnancies and the results related to perinatal outcome. Results: In the normal controls, right pulmonary artery PI remained stable until 30 weeks of gestation with slight increase thereafter until term. The MCA to right pulmonary artery PI ratio increased between 22 and 28 weeks of gestation with the rapid fall towards term. In the high-risk pregnancies group, right pulmonary artery PI showed no significant correlation to perinatal outcome, but signs of brain-sparing in the MCA were correlated to all adverse outcome parameters. Conclusion: Velocimetry of the middle cerebral artery is better than velocimetry of right pulmonary artery in predicting adverse outcome of pregnancy. The brain/lung PI ratio does not improve the prediction of adverse outcome of pregnancy.Wstęp: Ocena przepływu krwi przy pomocy metod dopplerowskich w krążeniu płucnym I mózgowym sugerowała istotny spadek perfuzji płuc w ciążach wysokiego ryzyka jako wykładnik zmienionej redystrybucji krwi w ustroju płodu. Stworzyło to koncepcję z której wynika, że stosunek perfuzji krwi w płucach i mózgu może być nową metodą oceniającą centralizację krążenia. Cel pracy: Celem badań było określenie współczynnika określającego stosunek przepływów krwi w płucach i mózgu w ciąży o przebiegu prawidłowym i w ciąży wysokiego ryzyka. Materiał i metody: Przepływ krwi oceniano metodą dopplerowska w proksymalnej części prawej tętnicy płucnej oraz w tętnicy środkowej mózgu w dwóch grupach pacjentek: u 228 ciężarnych z ciążą pojedynczą o przebiegu prawidłowym między 22 a 40 tygodniem ciąży oraz u 89 ciężarnych z ciążą wysokiego ryzyka. W oparciu o uzyskane wyniki obliczano stosunek wartości PI w naczyniach płucnych i mózgowych. Uzyskane wyniki odnoszono do stanu noworodka po porodzie. Wyniki: W grupie kontrolnej wartości PI tętnicy płucnej są stabilne aż do 30. tygodnia ciąży z następowym nieznacznym wzrostem aż do terminu porodu. Wartości stosunku PI w tętnicy środkowej mózgu do PI prawej tętnicy płucnej wzrastają między 22. a 28. tygodniem ciąży z następowym spadkiem do terminu porodu. W grupie ciąż wysokiego ryzyka, nie stwierdzono istotnej zależności między wartościami PI prawej tętnicy płucnej a stanem noworodka po porodzie. W tej grupie ciąż wykładniki centralizacji krążenia wykazywały zależność w odniesieniu do parametrów charakteryzujących zły stan noworodka po porodzie. Wnioski: Ocena przepływu krwi w tętnicy środkowej mózgu, w porównaniu z oceną przepływu w tętnicy płucnej, ma większą wartość predykcyjną w prognozowaniu stanu płodu. Analiza współczynnika – PI mózgu/PI płuc – nie poprawia tej oceny

Badanie ultrasonograficzne pola przekroju sznura pępowinowego w ciąży prawidłowej oraz powikłanej cukrzycą

Objective: A voluminous umbilical cord has been described in diabetic pregnancies. The aim of this study was to see if measurements of cord diameters might be of value in the evaluation of diabetic pregnancies and especially those suspected of a large for gestational age (LGA) fetus. Methods: In an observational, prospective study, umbilical cord areas and vessel diameters were measured between gestational age of 22 and 40 weeks in transverse ultrasound images of the central part of the cord in 141 normal and 135 diabetic pregnancies of which 30 were suspected of being LGA. Wharton’s jelly area was calculated by subtracting the vessel area from the total transverse cord area. Normal reference curves were constructed for gestational age. Results: Umbilical cord and Wharton’s jelly areas increased with gestation. The vessel area leveled out at 32-33 weeks of gestation and the umbilical vein area decreased after 36 weeks of gestation. The umbilical cord parameters in diabetic pregnancies did not differ from controls. Cord areas were enlarged in 1/3 of the LGA fetuses. Conclusion: Umbilical cord area measurements are of limited value for the evaluation of diabetic pregnancies suspected having a LGA-fetus.Cel badania: W piśmiennictwie opisuje się zwiększony wymiar sznura pępowinowego w ciąży powikłanej cukrzycą. Celem niniejszego badania była analiza przydatności wymiarów sznura pępowinowego w ocenie rozwoju płodu w ciąży powikłanej cukrzycą, w szczególności w przypadku podejrzenia nadmiernego wzrastania płodu (LGA). Materiał i metoda: Prospektywne badanie obserwacyjne z grupą kontrolną. Między 22 a 40 tygodniem ciąży mierzono przekroje poprzeczne sznura pępowinowego i poszczególnych naczyń pępowinowych w 141 ciążach prawidłowych oraz 135 ciążach powikłanych cukrzycą, w tym 30 ciążach powikłanych cukrzycą z podejrzeniem LGA. Pole powierzchni galarety Whartona obliczano przez odjęcie pól powierzchni naczyń pępowinowych od całkowitego pola powierzchni sznura pępowinowego. Skonstruowano krzywe wartości referencyjnych dla ciąży prawidłowej. Wyniki: Pole powierzchni sznura pępowinowego i galarety Whartona wzrastało wraz z wiekiem ciążowym. Pole powierzchni tętnicy pępowinowej osiągało plateau w 32-33 tygodniu ciąży, a pole powierzchni żyły pępowinowej zmniejszało się po 36 tygodniu ciąży. Nie zaobserwowano różnicy parametrów sznura pępowinowego porównując ciężarne chorujące na cukrzyce z grupą kontrolną. U 1/3 płodów z LGA zaobserwowano zwiększenie przekroju sznura pępowinowego. Wnioski: Pole powierzchni pępowiny ma ograniczoną przydatność w ocenie rozwoju płodu w ciąży powikłanej cukrzycą z podejrzeniem LGA

Amniotic fluid index in low-risk pregnancy as an admission test to the labor ward.

Background. Oligohydramnios has been shown to be a predictor of intrapartal fetal distress. In a selected group of low-risk pregnancies, however, it has not yet been established that oligohydramnios contributes to intrapartal fetal distress. Methods. Ultrasonically estimated four-quadrant amniotic fluid index as a test for admission to the labor ward was evaluated as a predictive factor for fetal distress during labor in a prospective 'blind' study comprising 600 low-risk pregnancies. Oligohydramnios was defined as an amniotic fluid index <= 50 mm. The parturients were divided into two groups according to the status of the fetal membranes. The amniotic fluid index results were correlated to fetal outcome: Apgar score at 1 and 5 min, pH of blood in umbilical artery and vein, operative delivery because of fetal distress, cesarean delivery because of fetal distress, and number of babies referred to the neonatal intensive care unit. Results. Two-hundred and sixty-seven women had ruptured membranes. Among these a significant increase in operative delivery because of fetal distress was seen in cases of oligohydramnios compared with the normal amount of amniotic fluid (odds ratio 3.86, confidence interval = 1.25-11.9). No significant differences were seen regarding other variables of perinatal outcome. The group with intact membranes comprised 333 parturients. Among these, no significant differences in perinatal outcome could be seen in relationship to the amniotic fluid index, although a 50% increase in emergency operations for fetal distress was seen in women with oligohydramnios. A significant correlation might have been evident even in that group if a larger sample had been studied. Conclusion. The results indicate that measurement of the amniotic fluid index in low-risk pregnant women admitted for labor might identify parturients with an increased risk of intrapartal fetal distress