Macrotransfusion fœto-maternelle spontanée révélée par une diminution de la perception des mouvements actifs fœtaux

Performance of the Kleihauer Betke test in the prediction of neonatal anemia

OBJECTIVES

The aim of this study was to correlate antenatal Kleihauer (KT) test results with fetal hemoglobin at birth to find a threshold for predicting severe fetal anemia. The secondary objectives were to assess the impact of KT on obstetric management and to study the correlation between the middle cerebral artery peack systolic velocity and fetal anemia.

RESULTS

One thousand forty-six KT were positive over the 10-year period, but only 147 were included from 88 patients, of which 17 fetuses were anemic. Demographic and obstetric characteristics were similar between anemic and non-anemic groups. As regards new-born, there was a higher risk of prematurity among anemic as long as a lower birth rate in accordance. While a negative correlation was observed between KT and hemoglobin at birth, no KT upper threshold could be found that was both sensitive and specific. In addition, there was no case of fetal anemia when KT was repeated, even though it increased. KT showed little usefulness in obstetrics management to help improving neonatal care for anemia. Conversely, the MCA PSV demonstrated good performance in this matter and the ROC curve area was 0.91 (figure).

DISCUSSION

Feto-maternal hemorrhage is a rare but grave pathology which could lead to anemia. The most common clinical sign is reduced fetal movement and it was the main indication to perform a KT. Cardiotocography patterns suggestive of anemia are sinusoidal, micro-oscillatory and non-reactive monitoring. Ultrasound features were polyhydramnios, hydrop fetalis and increased MCA peack systolic velocity. KT was correlated with MCA PSV and with hemoglobin level at birth. However, the latter showed a better diagnostic performance. MCA PSV measurement is a powerful test to screen for fetal anemia, and should be part of the regular training of obstetricians. Indeed, this technic gives immediate and reliable results, while those of KT are delayed.

CONCLUSION

The KT should not be used as a tool to screen for fetal anemia but rather as a test to explain a fetal anemia. However, the MCA PSV is reliable in this matter and give immediate result, thus obstetrician should be trained to routinely perform it.

[Acute per-partum feto-fetal transfusion. A case study on two sets of twins]

Description of acute per-partum feto-fetal transfusion. The risk of twin-twin transfusion syndrome in monochorionic twin pregnancies is well known. This pathology starts in the second trimester and has a chronic course. Acute per-partum feto-fetal transfusion seems to be less frequent and has not been studied. In the study, we described two cases of acute per-partum feto-fetal transfusion. The outcomes of the pregnancies were as follows: following a successful delivery, the first set of twins presented hypovolemic shock at birth due to an acute anemia. The second set of twins was polyglobulic, but otherwise healthy at birth. The risk of hypovolemic shock seems to be unpredictable, even if the pregnancy is monitored. Obstetricians and pediatricians must keep this pathology in mind when dealing with this kind of pregnancy. Moreover, it would be interesting to obtain systematically a full blood count of each set of twins of monochorionic pregnancies, in order to detect every case of feto-oetal transfusion.

[Decreased fetal movements in the third trimester: what to do?]

OBJECTIVE

To appreciate at the end of pregnancy, in a low-risk pregnant population, the interest of a screening for fetal well-being in case of decreased fetal movements. To define the most adapted screening.

PATIENTS AND METHODS

Retrospective study over a complete year of the patients having consulted in the same center for decreased fetal movements and subjected to the same screening for fetal activity in hospitalization during 48 hours. This screening included a study of fetal heart rate repeated three times a day, a fetal biophysical profile scoring, an umbilical artery Doppler, a Kleihauer-Betke testing, and an amnioscopy.

RESULTS

One hundred and sixty patients were identified, representing 6.1% of pregnancies followed in the center. There was no relation between the age, the parity of the patients and the probability to consult for a decrease of fetal movements. Nevertheless the antecedents of pathological pregnancy or fetal malformation were frequent. Twenty-one percent of the deliveries were induced for a global rate of 18% in the center. Twenty-eight percent of the patients had a cesarean section for a global rate of 22.8%. Five percent of fetuses were at risk for prenatal asphyxia on the data of the screening. Fetal heart rate was abnormal in 3.75% of cases, fetal biophysical profile score pathological in 3.1% of cases. Just one umbilical Doppler was highly pathological. No meconium amniotic fluid was found. Two Kleihauer-Betke tests were disturbing. At the time of delivery, 28% of fetuses presented a funicular abnormality, 4.3% a severe growth restriction, 4.3% a malformation. One child only had an anemia. There was no perinatal mortality.

DISCUSSION AND CONCLUSION

Screening for fetal vitality remains necessary in case of decreased fetal movements. It has to associate the study of fetal heart rate and the fetal biophysical profile with a Kleihauer-Betke testing. In a low-risk pregnant population, the study of fetal Doppler velocimetry is not profitable. Amnioscopy presents not enough interest. It is necessary to insist with the patients on the necessity of consulting in case of decreased fetal movements even in the approach of the term.