Doppler ultrasound velocimetry for timing the second intrauterine transfusion in fetuses with anemia from red cell alloimmunization.

OBJECTIVE: Middle cerebral artery peak systolic velocity has been successfully used for timing the first cordocentesis in fetuses who are at risk for anemia because of maternal red cell alloimmunization. The effects on Doppler velocimetry after the intrauterine transfusion of adult blood to these fetuses are unknown. The objective of this study was to assess the applicability of Doppler methods for the prediction of severe anemia in fetuses who had undergone 1 previous intrauterine transfusion. STUDY DESIGN: Doppler examination of middle cerebral artery peak systolic velocity was performed before cordocentesis in 64 fetuses who had undergone 1 previous intrauterine transfusion. Timing of the second intrauterine transfusion was based on traditional criteria. Anemia was defined as mild (hemoglobin value between 0.84 and 0.65 multiples of the median), moderate (hemoglobin value <0.65-0.55 multiples of the median), and severe (hemoglobin value <0.55 multiples of the median). Receiver operator characteristic curves were created to select threshold values to identify the 3 degrees of anemia with a sensitivity of 100%. RESULTS: Gestational age at the Doppler study ranged from 19 to 36 weeks. Forty-six fetuses (72%) were not or mildly anemic; 7 fetuses (11%) were moderately anemic, and 11 fetuses (17%) were severely anemic. Middle cerebral artery peak systolic velocity for the prediction of severe, moderate, and mild anemia at a sensitivity of 100% showed false-positive rates of 6%, 37%, and 70%, respectively. CONCLUSION: In fetuses who have undergone 1 previous intrauterine transfusion because of maternal red cell alloimmunization, timing the second intrauterine transfusion can be determined noninvasively by Doppler ultrasonography on the basis of an increase in the peak velocity of systolic blood flow in the middle cerebral artery.

Perinatal morbidity and mortality rates in severe twin-twin transfusion syndrome: results of the International Amnioreduction Registry.

OBJECTIVE: Serial aggressive amnioreduction is the most widely used therapy for pregnancies that are complicated by twin-twin transfusion syndrome. Survival rates reported with this therapy are 33% to 83%, the wide range attributable to the small number of patients in these case series. Similarly, data on morbidity in survivors are imprecise. We instituted the international twin-twin transfusion syndrome registry to determine the perinatal survival and morbidity rates and the factors that influence perinatal outcome in patients with twin-twin transfusion syndrome who were treated with serial aggressive amnioreduction from 1990 to 1998. STUDY DESIGN: A total of 223 sets of twins who were diagnosed with twin-twin transfusion syndrome before 28 weeks' gestation from 20 fetal medicine referral centers were analyzed, with follow-up data until 4 weeks after birth. RESULTS: Three hundred forty-six twins (78%; 182 recipients and 164 donors) were born alive. Two hundred sixty-six twins (60%; 144 recipients and 122 donors) were alive 4 weeks after birth. Both fetuses survived to 4 weeks in 108 pregnancies (48.4%), whereas, at least 1 fetus survived in 158 pregnancies (70.8%). The interval between the last amnioreduction and delivery ranged from zero to 138 days (median, 17.5 days). In the infants who survived to 4 weeks after birth, abnormalities on neonatal cranial scan were diagnosed in 24% of recipients and in 25% of donors. Logistic regression analysis indicated that the survival rate was significantly related to gestational age at diagnosis, presence of end-diastolic blood flow in the umbilical artery velocity waveforms, presence of hydrops, mean volume of amniotic fluid removed per week, larger birth weight, and gestational age at delivery. The hemoglobin level difference at birth was the only significant parameter to predict abnormal cranial ultrasonography in newborns. CONCLUSION: These data document perinatal survival and neonatal morbidity rates in severe twin-twin transfusion syndrome that were treated by serial aggressive amnioreduction. Outcome was influenced by several perinatal risk factors, which may be used to counsel patients before and during therapy.

Color Doppler ultrasonography of the superior mesenteric artery for prenatal ultrasonographic diagnosis of a left-sided congenital diaphragmatic hernia.

The incidence of congenital diaphragmatic hernia (CDH) has been estimated as 1 per 2000 to 1 per 4000 births. The etiology of the malformation is unknown, but it has been reported in association with maternal administration of medications such as thalidomide or antiepileptics before closure of the pleuroperitoneal canal at 9 to 10 weeks' gestation as well as having a familial inheritance pattern. Congenital diaphragmatic hernia is associated with other congenital anomalies in 25% to 57% of cases and with chromosomal abnormalities in 10% to 20% of cases. Posterolateral, anterolateral, and pars sternalis defects of closure of the pleuroperitoneal canal encompass the 3 types of CDH. The most frequent type is the left-sided posterolateral defect or Bochdalek's hernia, which accounts for 81% of cases.

Long-term outcome in twin-twin transfusion syndrome treated with serial aggressive amnioreduction.

OBJECTIVE: The purpose of this study was to determine long-term outcomes among pregnancies complicated by twin-twin transfusion syndrome and treated in a tertiary center with serial aggressive amnioreduction. STUDY DESIGN: Thirty-three pregnancies with a diagnosis of twin-twin transfusion syndrome were treated with > or =1 amnioreduction. The perinatal outcome was assessed according to 15 parameters, whereas the main outcome at age > or =2 years was the absence of cerebral palsy. RESULTS: Gestational age at diagnosis ranged from 14.5 to 33 weeks' gestation (median, 20.6 weeks' gestation), whereas gestational age at delivery was between 18.5 and 37 weeks' gestation (median, 30.5 weeks' gestation). The number of amnioreductions per pregnancy ranged from 1 to 15 (median, 2). At initial examination hydrops of the recipient and absence of the end-diastolic velocity of the umbilical artery in one of the twins were associated with poor prognosis. Fifty-one (77%) twins were born alive. At 24 months after birth both infants from 57% of the pregnancies (19/33) were alive, whereas at least one infant from 70% of the pregnancies (23/33) was alive. Thirty-three infants (78% of the survivors) were older than 36 months at last follow-up. Cerebral palsy was diagnosed in 2 of 42 infants (4.7%). One of the affected infants was born after the fetal death of the cotwin; the other infant was born with congenital cardiac malformations. CONCLUSIONS: In the group of fetuses in which both twins were delivered alive after 27 weeks' gestation without congenital malformations and survived the neonatal period, no major neurologic handicaps developed in any of the infants. At initial examination both hydrops of the recipient and absence of end-diastolic flow velocity waveforms of the umbilical artery in one of the twins were poor prognostic signs.

Noninvasive diagnosis by Doppler ultrasonography of fetal anemia due to maternal red-cell alloimmunization. Collaborative Group for Doppler Assessment of the Blood Velocity in Anemic Fetuses.

BACKGROUND: Invasive techniques such as amniocentesis and cordocentesis are used for diagnosis and treatment in fetuses at risk for anemia due to maternal red-cell alloimmunization. The purpose of our study was to determine the value of noninvasive measurements of the velocity of blood flow in the fetal middle cerebral artery for the diagnosis of fetal anemia. METHODS: We measured the hemoglobin concentration in blood obtained by cordocentesis and also the peak velocity of systolic blood flow in the middle cerebral artery in 111 fetuses at risk for anemia due to maternal red-cell alloimmunization. Peak systolic velocity was measured by Doppler velocimetry. To identify the fetuses with anemia, the hemoglobin values of those at risk were compared with the values in 265 normal fetuses. RESULTS: Fetal hemoglobin concentrations increased with increasing gestational age in the 265 normal fetuses. Among the 111 fetuses at risk for anemia, 41 fetuses did not have anemia; 35 had mild anemia; 4 had moderate anemia; and 31, including 12 with hydrops, had severe anemia. The sensitivity of an increased peak velocity of systolic blood flow in the middle cerebral artery for the prediction of moderate or severe anemia was 100 percent either in the presence or in the absence of hydrops (95 percent confidence interval, 86 to 100 percent for the 23 fetuses without hydrops), with a false positive rate of 12 percent. CONCLUSIONS: In fetuses without hydrops that are at risk because of maternal red-cell alloimmunization, moderate and severe anemia can be detected noninvasively by Doppler ultrasonography on the basis of an increase in the peak velocity of systolic blood flow in the middle cerebral artery.

Can a single measurement of amniotic fluid delta optical density be safely used in the clinical management of Rhesus-alloimmunized pregnancies before 27 weeks' gestation?

BACKGROUND: To assess the efficacy of a single measurement of amniotic fluid optical density deviation at 450 nanometers in predicting fetal anemia in Rhesus-alloimmunization before 27 weeks gestation. METHODS: In this cross-sectional study, fetal blood and amniotic fluid samples from 43 Rhesus-alloimmunized pregnancies at 18 to 26 weeks gestation were obtained under ultrasound guidance. Amniotic fluid samples were scanned by spectrophotometry for optic density at various wavelengths. Deviation at 450 nanometers was calculated between 550 and 365 nanometers. The fetuses were divided into three groups based on their hematocrit levels and the predictive efficacy of optic density zones for anemia was evaluated. RESULTS: A high number of false positive and false negative results were observed when the delta-amniotic fluid optical density of fetuses at risk for anemia was plotted to the zones recently proposed to manage Rhesus-alloimmunized pregnancies. CONCLUSIONS: These data confirm previous results that the diagnosis of fetal anemia in Rhesus-alloimmunized pregnancies before 27 weeks' gestation cannot be accurately made by a single measurement of amniotic fluid optical density at 450 nanometers.

"Pseudo" twin-to-twin transfusion syndrome and fetal outcome.

OBJECTIVE: To assess the fetal outcome, in a tertiary center, in pregnancies with suspected twin-to-twin transfusion syndrome (TTTS) not confirmed using ultrasonographic examination, diagnosis of pathology, or both. STUDY DESIGN: Forty-four pregnancies with suspected TTTS were followed longitudinally using ultrasonographic examination until delivery. The minimal criteria for the diagnosis of TTTS were: (1) suspicion of monochorionicity gleaned from ultrasound examination (to be confirmed at birth); (2) presence of polyhydramnios in one gestational sac (either assessed subjectively--or, finding that the largest vertical pocket of amniotic fluid was >8 cm in diameter before 20 weeks' gestation and >10 cm in diameter thereafter); and (3) presence of oligohydramnios in the other gestational sac (finding either that there was a "stuck" twin complication or that the largest vertical pocket of amniotic fluid was <1 cm in diameter). When one of the above criteria was not present, the pregnancy was defined as "pseudo" TTTS. Fetal outcome in "pseudo" TTTS was analyzed according to the relative size of the neonate (large or small) and whether the cord insertion was normal or velamentous. RESULTS: There were 18 cases of "pseudo" TTTS. No treatment in utero was necessary in any of the 18 pregnancies. The mean gestational age was 21.9 +/- 3.7 (1 SD) weeks at diagnosis and 33.0 +/- 3.0 weeks at delivery. The average weight discrepancy between the twins at birth was 34.3 +/- 14.8%. There were three fetal demises of the small twin and one neonatal demise of the large twin (p > 0.05). Large twins developed respiratory distress syndrome (RDS) more often than small twins (p < 0.05). Five percent of the large twins and 50% of the small twins had a velamentous insertion of the cord (p < 0.05). CONCLUSION: In pregnancies complicated by "pseudo" TTTS our data indicate that: (1) small twins have abnormal cord insertion more frequently than large twins, (2) large twins develop RDS more frequently than small twins. Our data suggest that the perinatal mortality in these pregnancies appears to be lower than that reported for the classical TTTS.

Reproducibility of ambulatory blood pressure monitoring results in pregnancy.

Blood pressure (BP) differences between two consecutive 24-h monitoring periods (P1, P2) were analyzed in 159 hospitalized pregnant women. Reproducibility index, or twice the standard deviation of differences between individual systolic and diastolic means, was better for 24-h (7.8 and 5.8) and daytime (8.7 and 6.3) than for nighttime (12.2 and 9.7) BP means. It did not depend on BP level or gestation week. Alert reaction to monitoring procedure increased BP only in the first 2 h of P1. The high overall reproducibility of ambulatory BP in pregnancy supports the expanding use of the technique also in this condition.

Superior mesenteric artery flow velocity waveforms in small for gestational age fetuses.

The objective of this study was to analyze the superior mesenteric artery flow velocity waveforms in small-for-gestational-age fetuses and to compare its contribution in their management with that already provided by the middle cerebral artery and umbilical artery flow velocity waveforms. Middle cerebral artery, umbilical artery, and superior mesenteric artery flow velocity waveforms were prospectively obtained in 41 small-for-gestational-age fetuses with color Doppler ultrasonography. The pulsatility index was used to quantify the waveforms. Poor perinatal outcome was defined by cesarean section for fetal distress, perinatal death, need for assisted ventilation, and necrotizing enterocolitis. In the small-for-gestational age fetuses, the middle cerebral artery pulsatility index was abnormal in 22/41, the umbilical artery in 26/41, and the superior mesenteric artery in 17/41. Coincident with abnormal umbilical and middle cerebral artery flow velocity waveforms were greater occurrences of poor perinatal outcome. The abnormality of an increased pulsatility index in the superior mesenteric artery velocity waveforms of small-for-gestational-age fetuses suggests greater vascular resistance and an overall reduction in visceral perfusion. However, the study of the superior mesenteric artery only seemed to support the information already provided for by the middle cerebral and umbilical arteries.

[Glycemic thresholds in spontaneous abortion during the first trimester in pregnant women with insulin dependent diabetes]. / Livelli glicemici "soglia" e aborto spontaneo nel I trimestre nelle gestanti affette da diabete mellito insulino-dipendente.

BACKGROUND AND AIM: To evaluate the hypothesis that insulin-dependent diabetic (IDDM) pregnant women have a threshold of glycemic control during the first trimester of pregnancy for an increased risk of spontaneous abortion. MATERIALS AND METHODS: Seventy IDDM pregnant women were enrolled before the 9th week of gestation and monitored throughout pregnancy. Fifteen pregnancies (21.4%) led to spontaneous abortion within the first trimester (study group) and 55 (76%) continued until term (control group). In order to evaluate the differences between the study group and the control group variance analysis and Student's t-test were used for constant variables and chi 2 and Fisher's exact test for discrete variables; p < 0.05 was considered statistically significance. RESULTS: Mean levels of glycosylated hemoglobin (HbA1c) and fructosamine at the initial prenatal visit were significantly higher in the study group (p < 0.03) compared to the control group. The threshold for an increased risk of spontaneous abortion in the first trimester was found to be initial concentrations > 8% for HbA1c and > 300 mmol/l for fructosamine. CONCLUSIONS: Pregnant women suffering from IDDM with initial HbA1c levels higher than 8% and fructosamine > 3 mmol/l have an increased risk of spontaneous abortion in the first trimester of pregnancy. Below this threshold the risk of spontaneous abortion during the first trimester of pregnancy is similar to that for non-diabetic pregnant women.