Effects of intravascular transfusion for red cell alloimmunization on fetal arterial blood pressure

Fluid shift from intravascular compartment during fetal red blood cell transfusion

OBJECTIVES

Intrauterine transfusion imposes a considerable burden on the fetal circulation by increasing volume and pressure, and a fluid shift from the fetal circulation occurs even during the procedure. The aim of this study was to quantify the intraprocedural fluid shift and to investigate the effect of procedural and fetal characteristics on this fluid shift.

METHODS

In 95 alloimmunized pregnancies, we calculated fluid shift at the first intrauterine transfusion by determining initial and final blood volumes. We evaluated the association of the fluid shift with the speed and volume of the transfusion, the severity of anemia and the presence of hydrops.

RESULTS

Of the included fetuses, 11 were mildly hydropic and four were severely hydropic. A mean fluid shift of 36% of the transfused volume was found. Fluid shift related positively to transfused volume (P < 0.001). The percentage fluid shift of transfused volume was inversely related to the speed of transfusion (mL/kg/min) (P < 0.041) and was not related to the severity of anemia (P = 0.55) or to hydrops (P = 0.66). It was found that younger fetuses had been unintentionally subject to high volumes and speeds of transfusion relative to their size.

CONCLUSIONS

Around one-third of the transfused volume is lost from the intravascular compartment during the procedure of intrauterine transfusion. There is a large variation between fetuses, partly explained by the volume and speed of the transfusion. Neither severity of anemia nor hydrops plays a clear-cut role, and thus other factors may explain the variation in fluid shift. The probability that hematocrit will still increase after transfusion, as a result of a continuing fluid shift, should be considered in transfusion policy. Advice is given on gestational age-adjusted speed of transfusion.

Techniques of intrauterine fetal transfusion for women with red-cell isoimmunisation for improving health outcomes

BACKGROUND

Red-cell alloimmunisation can occur when there are incompatibilities between a woman's blood type and that of her unborn baby. This can cause the baby to become anaemic (low red blood cell count), which may require treatment during the pregnancy by blood transfusion while the baby remains within the uterus (called an intrauterine blood transfusion).

OBJECTIVES

To compare, using the best available evidence, the benefits and harms of different techniques of intrauterine fetal blood transfusion for women with red-cell alloimmunisation.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (13 June 2012).

SELECTION CRITERIA

We considered randomised controlled trials comparing different techniques of intrauterine fetal blood transfusion (either alone or in combination with another technique) for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors evaluated trials under consideration for appropriateness for inclusion and methodological quality, without consideration of their results according to the prestated eligibility criteria. We planned to use a fixed-effect meta-analysis for combining study data if we judged the trials to be sufficiently similar. We planned to investigate statistical heterogeneity using the I² statistic; if this indicated a high degree of statistical heterogeneity, we planned to use a random-effects model.

MAIN RESULTS

Our search strategy identified four reports of three studies for consideration, of which two met the inclusion criteria, involving 44 women. We identified a single trial comparing the use of intrauterine fetal blood transfusion and intravenous immunoglobulin versus intrauterine fetal blood transfusion alone, and a single trial comparing the use of atracurium and pancuronium. There were no statistically significant differences identified for any of the reported outcomes.

AUTHORS' CONCLUSIONS

There is little available high quality information from randomised controlled trials to inform the optimal procedural technique when performing fetal intrauterine fetal blood transfusions for women with an anaemic fetus due to red cell alloimmunisation. Further research evaluating the benefits and harms associated with different techniques is required.

Techniques of intrauterine fetal transfusion for women with red-cell isoimmunisation for improving health outcomes

BACKGROUND

Red-cell alloimmunisation can occur when there are incompatibilities between a woman's blood type and that of her unborn baby. This can cause the baby to become anaemic (low red blood cell count), which may require treatment during the pregnancy by blood transfusion while the baby remains within the uterus (called an intrauterine blood transfusion).

OBJECTIVES

To compare, using the best available evidence, the benefits and harms of different techniques of intrauterine fetal blood transfusion for women with red-cell alloimmunisation.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (March 2010).

SELECTION CRITERIA

We considered randomised controlled trials comparing different techniques of intrauterine fetal blood transfusion (either alone or in combination with another technique) for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors evaluated trials under consideration for appropriateness for inclusion and methodological quality, without consideration of their results according to the prestated eligibility criteria. We planned to use a fixed-effect meta-analysis for combining study data if we judged the trials to be sufficiently similar. We planned to investigate statistical heterogeneity using the I(2) statistic; if this indicated a high degree of statistical heterogeneity, we planned to use a random-effects model.

MAIN RESULTS

Our search strategy identified four reports of three studies for consideration, of which two met the inclusion criteria, involving 44 women. We identified a single trial comparing the use of intrauterine fetal blood transfusion and intravenous immunoglobulin versus intrauterine fetal blood transfusion alone, and a single trial comparing the use of atracurium and pancuronium. There were no statistically significant differences identified for any of the reported outcomes.

AUTHORS' CONCLUSIONS

There is little available high quality information from randomised controlled trials to inform the optimal procedural technique when performing fetal intrauterine fetal blood transfusions for women with an anaemic fetus due to red cell alloimmunisation. Further research evaluating the benefits and harms associated with different techniques is required.

Fetal intraperitoneal transfusion for iatrogenic twin anemia-polycythemia sequence after laser therapy

Twin anemia-polycythemia sequence (TAPS) is a rare variant of twin-twin transfusion syndrome (TTTS) without the characteristic twin oligohydramnios-polyhydramnios sequence and cardiovascular milieu attributed to renin-angiotensin system mediators. It can occur spontaneously or iatrogenically after fetoscopic laser surgery. We report the case of a woman, gravida 2 para 1, with a monochorionic diamniotic pregnancy who developed Quintero Stage III TTTS. She underwent laser photocoagulation of identifiable anastomotic vessels and subsequently developed suspected TAPS 2 weeks later. The pregnancy was successfully treated with serial intrauterine intraperitoneal transfusions (IUT-PTs) of red blood cells. Although TAPS is a rare condition, serial middle cerebral artery peak systolic velocity measurements are warranted as follow-up in patients who have undergone fetoscopic laser surgery for TTTS. IUT-PTs may be superior to intravascular intrauterine transfusions in the treatment of this condition.

Fetal cardiac contractility before and after intrauterine transfusion

OBJECTIVE

To evaluate the effect of fetal anemia and intrauterine transfusion on ventricular shortening fraction.

METHODS

The end-diastolic and end-systolic transverse dimensions of the left and right ventricles were obtained using M-mode ultrasonography. The shortening fractions of both ventricles were calculated at three time points: before, immediately after and one day after intrauterine transfusion. The blood volume given at intrauterine transfusion was expressed as a percentage of estimated fetoplacental blood volume.

RESULTS

Complete measurements were obtained from 49 transfusions in 23 fetuses. Intrauterine transfusion was performed at a median gestational age of 31 (range, 19-35) weeks. Median hemoglobin concentration before and after intrauterine transfusion was 7.9 (range, 2.7-13.7) g/dL and 14.3 (range, 12.7-16.1) g/dL, respectively. Both left and right ventricular shortening fractions differed significantly between the three time points. Left ventricular shortening fraction decreased immediately after transfusion in 43 (88%) of the 49 procedures. Right ventricular shortening fraction decreased immediately after transfusion in 42 (86%) of the 49 procedures. At the first intrauterine transfusion, there was only a weak correlation between the decrease in shortening fraction of both ventricles and the transfused volume (left: R(2) = 0.15; P = 0.20/right: R(2) = 0.005; P = 0.81).

CONCLUSION

Transfusion significantly decreases the shortening fraction of both ventricles of the fetal heart. There is, however, little correlation between the decrease in shortening fraction and the volume of red cells given at intrauterine transfusion. Published by John Wiley & Sons, Ltd.

Complications of intrauterine intravascular transfusion for fetal anemia due to maternal red-cell alloimmunization

OBJECTIVE

The purpose of this study was to establish the true procedure-related complication rate of intrauterine transfusion therapy.

STUDY DESIGN

A cohort study of 254 fetuses treated with 740 intrauterine blood transfusions for red-cell alloimmunization in a single center in the years 1988 to 2001. Our database was searched for perinatal deaths, emergency deliveries, infections, and preterm rupture of membranes associated with intrauterine blood transfusion. Complications were categorized by two independent obstetricians as procedure-related (PR) or not procedure-related (NPR). Logistic regression analysis was used to identify risk factors for complications.

RESULTS

Overall survival was 225/254 (89%). Fetal death occurred in 19 cases (7 PR) and neonatal death in 10 cases (5 PR). There were two cases of intrauterine infection with Escherichia coli (both PR) and two other cases of preterm premature rupture of membranes (1 PR) within a week of a procedure. Emergency delivery after a transfusion was performed in 18 pregnancies (15 PR). The total PR complication rate was 3.1%, resulting in an overall PR loss rate of 1.6% per procedure. Arterial puncture, transamniotic cord puncture, refraining from fetal paralysis, and advancing gestational age were associated with the occurrence of PR complications.

CONCLUSION

Our study shows that intrauterine transfusion is a safe procedure, with a relatively low PR perinatal loss rate. Arterial puncture and transamniotic cord needling carry a high risk for serious complications, whereas fetal paralysis improves the safety of the procedure. This information on risks of intrauterine transfusion therapy may help to further improve the safety of intrauterine transfusions. Data on complication rates of intrauterine transfusions are essential in counseling patients.