Detection and measurement of fetomaternal hemorrhage following diagnostic cordocentesis

Maternal Risk Factors and Their Effect on Outcome and Procedure-Related Complications in Cordocentesis: A Multicenter Retrospective Study

BACKGROUND

Cordocentesis is used in clinical situations in which lower-risk diagnostic procedures do not deliver the desired results. The aim of this study was to evaluate the risk for procedure-related complications and fetal loss in correlation to maternal risk factors.

METHODS

This is a multicenter retrospective study investigating the complications, risk factors and perinatal outcome of diagnostic cordocentesis between 1998 and 2019 in three different centers.

RESULTS

A total of 1806 cordocenteses were performed and procedure-related complications (IUFD within 48 h, contractions, bradycardia, unsuccessful puncture, chorioamniotic separation) were noted in 1.6% of cases. Fetuses with chromosomal aberrations, intrauterine growth restriction and hydropic fetuses had a significantly higher rate of fetal loss compared to other indications. Fetal blood sampling (FBS) performed before 17+0 weeks of gestation was associated with a higher risk of procedure-related complications. Maternal BMI ≥ 40 increased the risk for fetal loss, whereas maternal age, number of previous miscarriages, number of previous abortions, history of vaginal bleeding or nicotine abuse did not affect the risk for complications or overall fetal loss rate.

CONCLUSIONS

In the hands of experienced operators, FBS is a safe way to further fetal diagnostics, and the risk of complications is low.

Risk factors for fetomaternal bleeding after laser therapy for twin-twin transfusion syndrome

OBJECTIVE

To quantify and assess potential risk factors for transplacental passage of fetal red blood cells (RBCs) into the maternal circulation (fetomaternal bleeding, FMB) after laser surgery for twin-twin transfusion syndrome (TTTS).

STUDY DESIGN

A retrospective study of Rhesus-D negative patients that underwent laser surgery for TTTS. Patients with and without postoperative detectable fetal RBCs on Kleihauer-Betke (KB) testing were compared to determine risk factors for FMB. Patients were further sub-classified into those with a FMB < 20% and ≥20% of estimated fetoplacental blood volume.

RESULTS

Of 60 studied patients, 26/60 (43%) had a positive postoperative KB test. The median fetal:adult RBC ratio was 0.00125, estimated to be a FMB volume of 6.25 mL. There were 17/26 (65%) of patients with FMB < 20% and 9/26 (35%) patients with ≥20% of the fetoplacental blood volume. Stage III-Recipient and III-Recipient/Donor patients were more likely to have a positive KB test (14/21 [66.7%] vs 12/39 [30.8%], OR = 4.50 [1.27-16.54], P = 0.0162). No other risk factors for FMB were apparent.

CONCLUSIONS

Fetomaternal bleed appears to be a common finding after laser surgery for TTTS. TTTS Stage, particularly stage III-Recipient and III-Recipient/Donor, appears to be a risk factor for FMB.

Biomechanical evaluation of interlocking lag screw design in intramedullary nailing of unstable pertrochanteric fractures

OBJECTIVES

Intramedullary nails with special lag screw designs may provide improved mechanical performance and alleviate clinical problems. We hypothesize that the proximal design of trochanteric nails affects mechanical performance.

METHODS

Ten pairs of human cadaveric femora were implanted with 2 different short intramedullary nails without (Gamma3) and with an interlocking lag screw (Intertan). An unstable, multifragmentary, pertrochanteric fracture was created. Bones were tested in a cyclic testing protocol with increasing loads until failure simulating 1 leg stance. Stiffness, failure load, cycles to failure, and fracture gap movements were measured.

RESULTS

Initially stiffness of the interlocking lag screw nail was almost 40% larger (P = 0.005) compared with the noninterlocking nail. During the test, the difference in stiffness gradually decreased. Failure load (13%, P = 0.02) and cycles to failure (18%, P = 0.02) were larger for the interlocking nail construct. Rotation and varus collapse of the head were initially up to 84% lower (P = 0.013) for the interlocking technique. During the test, the rate of rotational instability gradually increased for both techniques.

CONCLUSIONS

The interlocking lag screw design reduced movement of the femoral head and relative movement between fracture fragments. Beyond that the trapezoidal nail design of the Intertan reduced toggling within the trochanteric area and prolonged survival. Although this study showed a decrease in the retention of stability over time, failure did not occur until the equivalent of 2-3 months of reduced physical activity in which healing may have occurred under normal clinical conditions.

Significance of the volume of fetomaternal hemorrhage after performing prenatal invasive tests

BACKGROUND

Fetal erythrocytes cross the placenta during gestation, but invasive prenatal procedures might develop into fetomaternal hemorrhage (FMH). We examine whether flow cytometry immunophenotyping might be useful for measuring the volume of FMH after such procedures.

METHODS

Fetal erythrocytes (%) were determined in 153 pregnant women after amniocentesis (129) and chorionic villous sampling (24) using a monoclonal antibody against fetal hemoglobin. Fetal erythrocytes were identified for their high expression of fetal hemoglobin (HbF(++) ). Blood samples from two control groups, 53 healthy males and 21 pregnant women not submitted to invasive tests, were used to establish normal values of circulating HbF(++) erythrocytes in adults.

RESULTS

The highest percentage of HbF(++) erythrocytes in the control groups was 0.015%. The rate of HbF(++) erythrocytes in samples after invasive tests ranged between <0.01% and 0.15%. Seventy-three women (47%) had ≤0.015% HbF(++) erythrocytes, and this rate was higher in 80. Nine women presented >1 ml of FMH (volume of packed cells corresponding to 0.054-0.15% HbF(++) erythrocytes), but only two had sonographic evidence of bleeding.

CONCLUSIONS

Most women in our series had a very low volume of FMH after the invasive tests. Acute bleeding should be thoroughly investigated in women with either more than 1 ml of packed cells or more than 0.05% of HbF(++) erythrocytes. Intermediate values between >0.015% and <0.05%, should be carefully considered depending on the week of gestation. Data obtained before 15 weeks might reflect previous cell trafficking between fetus and mother instead of acute hemorrhage.

Current clinical management of anti-Kell alloimmunization in pregnancy

OBJECTIVES

Few reports have been published of the current clinical management of anti-Kell alloimmunization in pregnancy; its low frequency of occurrence means that the few long series published have covered very ample time periods in which different kinds of clinical management have overlapped. The objective of the present paper is to present our experience in the current clinical management of pregnant women who are positive for the anti-Kell antibody.

STUDY DESIGN

A retrospective analysis was carried out of the case histories of pregnant women who were alloimmunized for the Kell antigen and who were studied and/or treated at the Department of Fetal Medicine in the Virgen de las Nieves University Hospital in Granada (Spain), between 2000 and 2004. The clinical management included the basal measurement of the titre of antibodies, the identification of the paternal phenotype (and that of the fetus, if necessary), the ultrasonographic monitoring of the fetus to detect signs of anaemia, sampling of fetal blood by cordocentesis when fetal anaemia was suspected, and fetal intravascular transfusion when necessary.

RESULTS

Of the 10 pregnancies with anti-Kell antibodies, The Kell antigen was confirmed in the fetus in three cases, in all of which moderate to severe fetal anaemia developed, requiring fetal intravascular transfusions. Although one of the fetus developed antenatal hydrops, a good perinatal result was advised.

CONCLUSIONS

The current approach to anti-Kell alloimmunization enables pregnant women who have Kell-positive fetuses to be treated successfully.

Treatment Options in Fetomaternal Hemorrhage: Four Case Studies

BACKGROUND

Significant fetomaternal hemorrhage (FMH) is an uncommon event that places the fetus at risk of severe morbidity and mortality. Symptoms and signs at presentation are subtle and, if promptly recognized, appropriate management may permit the fetus to escape serious injury.

CASES

Four cases of significant FMH were diagnosed in the high-risk obstetrical unit at Mount Sinai Hospital, Toronto, during 2003. Three of the women complained of reduced fetal movements and were investigated initially with a non-stress test, a Kleihauer-Betke test, and ultrasound, including Doppler of the middle cerebral artery. These women all required emergency Caesarean section for non-reassuring fetal status. One fetus was treated by intravascular transfusion. Another identified case was transfused postnatally. One asymptomatic case was identified after spontaneous vaginal birth and also treated by neonatal transfusion. Neurological outcomes were good in all four cases.

CONCLUSIONS

Reduced fetal movements may be the only complaint of FMH. Increased awareness is required to ensure a diagnosis is made. When a non-stress test for reduced fetal movement is non-reactive, a Kleihauer-Betke test should be ordered, as well as detailed ultrasonography, including fetal Doppler studies. The perinatal prognosis for FMH may improve by facilitating the appropriate use of fetal blood transfusion or delivery by Caesarean section.

Is the incidence of fetal-to-maternal hemorrhage increased in patients with third-trimester bleeding?

OBJECTIVE

If a pregnancy is complicated by third-trimester bleeding, is there a higher risk of fetal-to-maternal hemorrhage that might necessitate the administration of additional anti-D immune globulin to prevent alloimmunization in the patient who is Rh D-negative? The study objective was to analyze prospectively the incidence of fetal-to-maternal hemorrhage in pregnancies that were complicated by third trimester bleeding compared with three control groups.

STUDY DESIGN

Pregnancies that were complicated by third-trimester bleeding, preterm premature rupture of the membranes, and preterm labor were identified prospectively on admission. A group of preterm patients with no complications was also collected prospectively. Patients with any history and/or clinical evidence of trauma were excluded. Kleihauer-Betke tests were performed with all patients, and the results were blinded until study completion. Sample size calculations were performed to determine the minimum number of cases needed in each group.

RESULTS

A total of 403 patients were collected during the study period: 91 patients had third-trimester bleeding, 101 patients had preterm premature rupture of the membranes, 116 patients had preterm labor, and 95 patients were in the no complication group. There was no statistical difference identified in the Kleihauer-Betke test results between any of the study groups.

CONCLUSION

The incidence of fetal-to-maternal hemorrhage does not appear to be increased in pregnancies that are complicated by third-trimester bleeding when compared to noncomplicated control subjects or to other obstetrically complicated pregnancies. This information would suggest that the routine administration of additional anti-D immune globulin (beyond the current recommended protocol) to women who are Rh D-negative whose pregnancies are complicated by third-trimester bleeding is not indicated.