An Audit of Outcome in Intravascular Transfusions Using the Intrahepatic Portion of the Fetal Umbilical Vein Compared to Cordocentesis

Effective management of foetal anaemia in Rh(D) alloimmunised pregnant women with intrauterine transfusion: a Systematic Review

BACKGROUND

Foetal anaemia is caused by a severe pregnancy complication, haemolytic disease of the foetus and newborn. Intrauterine transfusions (IUTs) are performed to treat foetal anaemia in alloimmunised pregnant women. If left untreated hydrops can develop thereby reducing the chance of survival. Survival rates have improved but the procedure is not without complications. Procedure-related complications can be associated with early gestational age, hence delaying IUT could improve outcomes. This review aims to determine the effectiveness and safety of IUTs by examining survival and mortality rates, procedure-related complications with associated foetal mortality and the influence of hydrops.

STUDY DESIGN AND METHOD

A systematic review was conducted by searching keywords in four scientific databases from January 2000 to April 2022. A meta-analysis was performed with the OpenMeta-Analyst software using an arcsine transformed proportion with the binary random-effects model and maximum likelihood method.

RESULTS

Fifteen studies were identified as eligible and used in the meta-analysis. The forest plots all showed statistically significant outcomes with heterogeneity of data. Results indicated a greater foetal survival rate with IUT to treat anaemic foetuses, a low foetal mortality rate, and low risk of procedure-related complications associated with foetal loss but a higher risk of foetal mortality when hydrops is present.

CONCLUSION

The findings of this systematic review and meta-analysis provide evidence that IUT is a safe and effective treatment for foetal anaemia in the absence of hydrops when experienced personnel perform the procedure to minimise the risk of procedure-related complications.

Severity of haemolytic disease of the fetus and newborn in patients with a history of intrauterine transfusions in a previous pregnancy: A nationwide retrospective cohort study

OBJECTIVE

Pregnant women who received at least one intrauterine transfusion (IUT) for haemolytic disease of the fetus and newborn (HDFN) in the preceding pregnancy are presumed to have a high likelihood of requiring IUTs again, often starting at an earlier gestational age. Our aim was to quantify these risks in a large national cohort.

DESIGN

Retrospective cohort study of a nationwide Dutch database.

SETTING

The Netherlands.

POPULATION

All women treated in The Netherlands with IUTs for Rhesus D (RhD)- or Kell-mediated HDFN between 1999 and 2017 and their follow-up pregnancies were included. Pregnancies with an antigen-negative fetus were excluded.

METHODS

Electronic patient files were searched for the number and gestational age of each IUT, and analysed using descriptive statistics and linear regression.

MAIN OUTCOME MEASURES

Percentage of women requiring one or more IUTs again in the subsequent pregnancy, and gestational age at first IUT in both pregnancies.

RESULTS

Of the 321 women in our study population, 21% (69) had a subsequent ongoing pregnancy at risk. IUTs were administered in 86% (59/69) of cases. In subsequent pregnancies, the median gestational age at first IUT was 3 weeks earlier (interquartile range -6.8 to 0.4) than in the preceding pregnancy.

CONCLUSIONS

Our study shows that pregnant women with a history of IUTs in the previous pregnancy are highly likely to require IUTs again, and on average 3 weeks earlier. Clinicians need to be aware of these risks and ensure timely referral, and close surveillance from early pregnancy onwards. Additionally, for women with a history of IUT and their caregivers, this information is essential to enable adequate preconception counselling.

Accuracy of a portable hemoglobinometer (HemoCue) to measure fetal hemoglobin values during in utero transfusion

OBJECTIVES

The current recommended treatment for severe fetal anemia is in utero transfusion (IUT). During this procedure, the evaluation of the necessary volume of transfused blood is based on regular measurement of fetal hemoglobin (FHb) concentration. The gold standard measurement is performed in the biology laboratory. A rapid medical test such as HemoCue® is an effective way to predict FHb concentration. It would reduce the time to obtain results and therefore the procedure duration. To evaluate the accuracy of HemoCue® to measure FHb during IUT, we compared Hb levels obtained by HemoCue® and by our biology laboratory.

METHODS

This retrospective study involved all pregnant women who had undergone an IUT in the university hospital of Clermont-Ferrand, France, during the period from 1 January 2010 to 6 June 2021. The FHb level was evaluated by two methods, a rapid medical test, HemoCue®, and a standard method in the biology laboratory.

RESULTS

We obtained 244 pairs of results from HemoCue® and our laboratory, of 90 IUT procedures. The correlation between the two sets of results was excellent, with Lin's concordance correlation coefficient of 0.979. However, we established that the measurements were not significantly modified by IUT number, puncture time, cause of fetal anemia, estimated fetal weight, gestational age, and delay between two IUT or middle cerebral artery peak systolic velocity values.

CONCLUSION

Our results allowed to extend the relevance of FHb measurements by HemoCue® during IUT.

Hemolytic disease of the fetus and newborn: systematic literature review of the antenatal landscape

BACKGROUND

Prevention of pregnancy-related alloimmunization and the management of hemolytic disease of the fetus and newborn (HDFN) has significantly improved over the past decades. Considering improvements in HDFN care, the objectives of this systematic literature review were to assess the prenatal treatment landscape and outcomes of Rh(D)- and K-mediated HDFN in mothers and fetuses, to identify the burden of disease, to identify evidence gaps in the literature, and to provide recommendations for future research.

METHODS

We performed a systematic search on MEDLINE, EMBASE and clinicaltrials.gov. Observational studies, trials, modelling studies, systematic reviews of cohort studies, and case reports and series of women and/or their fetus with HDFN caused by Rhesus (Rh)D or Kell alloimmunization. Extracted data included prevalence; treatment patterns; clinical outcomes; treatment efficacy; and mortality.

RESULTS

We identified 2,541 articles. After excluding 2,482 articles and adding 1 article from screening systematic reviews, 60 articles were selected. Most abstracted data were from case reports and case series. Prevalence was 0.047% and 0.006% for Rh(D)- and K-mediated HDFN, respectively. Most commonly reported antenatal treatment was intrauterine transfusion (IUT; median frequency [interquartile range]: 13.0% [7.2-66.0]). Average gestational age at first IUT ranged between 25 and 27 weeks. weeks. This timing is early and carries risks, which were observed in outcomes associated with IUTs. The rate of hydrops fetalis among pregnancies with Rh(D)-mediated HDFN treated with IUT was 14.8% (range, 0-50%) and 39.2% in K-mediated HDFN. Overall mean ± SD fetal mortality rate that was found to be 19.8%±29.4% across 19 studies. Mean gestational age at birth ranged between 34 and 36 weeks.

CONCLUSION

These findings corroborate the rareness of HDFN and frequently needed intrauterine transfusion with inherent risks, and most births occur at a late preterm gestational age. We identified several evidence gaps providing opportunities for future studies.

Perinatal Outcome of Pregnant Women with RhD Sensitization: A Five-Year Cross-Sectional Study at a Tertiary Care Hospital in Ethiopia

Background

Isoimmunization is a process of immunizing an antigen-negative pregnant individual with a paternally derived fetal antigen. Although the Rh systems contain many antigen subtypes (D, C, c, E, e), the RhD antigen is highly immunogenic. This research aimed to investigate the perinatal Outcome of pregnant women with RhD sensitization at St. Paul's Hospital Millennium Medical College (SPHMMC), Ethiopia.

Methodology

A facility-based retrospective cross-sectional study was conducted on 98 pregnant women with RhD alloimmunization at SPHMMC from September 11, 2016, to September 10, 2021. SPSS 26 was used for data analysis. Descriptive statistics were utilized to assess the perinatal outcome of pregnant women with RhD alloimmunization. Fisher's exact test was used to determine which association, and a P value <0.05 was considered statistically significant.

Results

From the 98 pregnancies (06 - hydropic, 92 - non-hydropic) at high risk for fetal anemia, 45.9% of cases had MCA-PSV above 1.5MoM. Among these, 21.42% of all fetuses received an intrauterine transfusion. Forty-three IUTs were performed in 21 fetuses. The median number of transfusions per fetus was two. About 52.4% of the transfused fetuses had severe anemia, and 28.6% had moderate anemia. Prediction of MCA PSV ≥1.5MOM in diagnosing moderate-severe anemia in pregnant women with RhD sensitization 81%. General neonatal survival of alloimmunizations was 93.8%, 90.5% with IUT, 50% with hydrops fetalis, and 96.7% without hydrops.

Conclusion

This research provides evidence that MCA PSV ≥1.5MoM is modest predictor of moderate-severe anemia in untransfused fetuses. This study was a step toward the development of more extensive and multicenter studies on the Perinatal Outcome of pregnant women with RhD sensitization in Ethiopia. Extra studies are needed to evaluate strategies for estimates of fetal anemia after blood transfusion as a result of the absence of information on the IUT database.

Perinatal outcomes and central nervous system abnormalities following intrauterine fetal transfusion: 17 years' experience in a tertiary center

BACKGROUND

This study aimed to describe the perinatal outcome and central nervous system (CNS) anomalies in fetuses undergoing red blood cell (RBC) intrauterine transfusion (IUT).

METHODS AND MATERIALS

This was an observational single-cohort study carried out at Vall d'Hebron University Hospital in Barcelona, Spain, between 2002 and 2018 in women undergoing RBC IUT for suspected fetal anemia. Primary outcomes were adverse perinatal outcome (intrauterine or neonatal death and termination of pregnancy [TOP]), prenatal or postnatal CNS anomalies, and significant neurological impairment.

RESULTS

A total of 145 RBC transfusions were performed in 68 pregnancies of 60 women. The median gestational age for the first transfusion was 26 weeks (range, 18-32). Twenty-two (32%) fetuses were hydropic at the first transfusion. Fifty-eight pregnancies (85.3%) resulted in live births and 10 (14.7%) in adverse perinatal outcomes. Adverse perinatal outcomes were associated with hydrops (odds ratio [OR], 6.69; 95% confidence interval [CI], 1.53-29.23; P = .012) and gestational age at first transfusion (OR, 0.69; 95% CI, 0.54-0.89; P = .04). Four (5.9%) cases of cerebellar hemorrhage were diagnosed prenatally. In 14 (35%) of the 41 neonates undergoing brain ultrasound and/or magnetic resonance imaging (MRI) abnormalities were reported. The median follow-up was 6.5 years (range, 3 months to 19 years). Significant neurological impairment was reported in two cases (4.2%).

CONCLUSION

In fetuses undergoing intrauterine RBC transfusion, the survival rate is high, particularly in the absence of hydrops and if the gestational age at first transfusion is above 22 weeks. Significant neurological impairment is uncommon, despite the fact that postnatal CNS anomalies at ultrasound or MRI are frequent.

Medical therapy to attenuate fetal anaemia in severe maternal red cell alloimmunisation

Haemolytic disease of the fetus and newborn (HDFN) remains an important cause of fetal mortality with potential neonatal and longer-term morbidity. HDFN is caused by maternal red cell alloimmunisation, with IgG antibodies crossing the placenta to destroy fetal erythroid cells expressing the involved antigen. Intrauterine fetal blood transfusion is the therapy of choice for severe fetal anaemia. Despite a strong evidence base and technical advances, invasive fetal therapy carries risk of miscarriage and preterm birth. Procedure-related risks are increased when invasive, in utero transfusion is instituted prior to 22 weeks to treat severe early-onset fetal anaemia. This review focuses upon this cohort of HDFN and discusses intravenous immunoglobin (IVIg) and novel monoclonal antibody (M281, nipocalimab) treatments which, if started at the end of the first trimester, may attenuate the transplacental passage and fetal effects of IgG antibodies. Such therapy has the ability to improve fetal survival in this severe presentation of HDFN when early in utero transfusion may be required and may have wider implications for the perinatal management in general.

Red cell alloimmunization: A 2020 update

Management of maternal red cell alloimmunization has been revolutionized over the last 60 years. Advances in the prevention, screening, diagnosis, and treatment of alloimmune-induced fetal anemia make this condition an exemplar for contemporary practice in fetal therapy. Since survival is now an expectation, attention has turned to optimization of long-term outcomes following an alloimmunized pregnancy. In this review, the current management of red cell alloimmunization is described. Current research and future directions are discussed with particular emphasis on later life outcomes after alloimmune fetal anemia.

[Outcome of in utero transfusion in case of fœtomaternal red blood cell incompatibility]

OBJECTIVE

Erythrocyte allo-immunization's rate has decreased but without adapted treatment the prognosis is still poor. The aim of our study was to evaluate the fetal prognosis, the complication's rate and the risk factors of complications of the intrauterine transfusion.

METHODS

Retrospective study about 37 fetus and 86 intrauterine transfusions between 2001 and 2017. Our main criterion in judging was the occurrence of procedure related complications: premature membrane rupture or premature delivery within seven days from the procedure, chorioamnionitis, abnormal fetal heart rate indicating an emergency ceasarean section within the 24hours from the procedure, in utero death or neonatal death related to the procedure.

RESULTS

The survival rate was about 88.9% with a severe complication's rate of 5.8% per intrauterine transfusion and 13.5% per pregnancy. Intrauterine transfusions before 18 weeks of pregnancies was a complication risk factor: 50% of complications before 18 weeks vs. 1.3%, P=0.8×10^-3. On the contrary, hydrops did not seem to be a complication risk factor (16.7% of complication with hydrops vs. 3.9%, P=0.27). The localisation of the needle insertion, intra-abdominal or placental insertion, had no effect on the fetal prognosis.

CONCLUSION

Intrauterine transfusion complications are rare and it enhances the fetal prognosis. However, an early procedure is related to a higher rate of complications.

Complications of intrauterine intravascular blood transfusion: lessons learned after 1678 procedures

OBJECTIVE

Maternal alloimmunization to fetal red-blood-cell antigens is a major cause of fetal anemia, which can lead to hydrops and perinatal death if untreated. The cornerstone of management during pregnancy is intrauterine intravascular blood transfusion (IUT). Although this procedure is considered relatively safe, complications continue to occur. The aim of this study was to evaluate rates of procedure-related complications and perinatal loss following IUT, and their change over time, in order to identify factors leading to improved outcome.

METHODS

This was a retrospective analysis of all IUTs for red-cell alloimmunization performed at the national referral center for fetal therapy in The Netherlands, from 1988 to 2015. Differences in complication rates and their associations with alterations in transfusion technique after 2001 were assessed.

RESULTS

Between 1988 and 2015, 1678 IUTs were performed in 589 fetuses. For IUTs performed in 2001 and onwards, there was significant improvement in survival (88.6% vs 97.0%, P < 0.001) and a decline in procedure-related complications per fetus (9.8% vs 3.3%, P = 0.001) and per procedure (3.4% vs 1.2%, P = 0.003) compared with those performed before 2001. Procedure-related perinatal loss declined from 4.7% to 1.8% per fetus (P = 0.053). Beneficial changes in transfusion technique were routine use of fetal paralysis, increased use of intrahepatic transfusion and avoidance of arterial puncture.

CONCLUSIONS

IUT has become an increasingly safe procedure in recent years when performed by experienced hands. The chosen technique should be fine-tuned according to the patient's individual situation. The declining complication rates are most likely related to center volume: this rare procedure is best performed in experienced fetal therapy centers. © 2016 Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Fetal Intracardiac Transfusions in Hydropic Fetuses with Severe Anemia

Introduction: Fetal anemia can have significant perinatal morbidity and mortality, particularly with onset prior to 20 weeks of gestation. Materials and Methods: We detail a case-cohort study (n = 8) of all women who underwent fetal in-utero, intracardiac transfusion prior to 24 weeks of gestation (7 women before 20 + 1 weeks), between March 2004 and September 2014, in a supraregional Fetal Medicine Center in the United Kingdom, comprising 2.2% of all transfusions performed during this period. All the fetuses were hydropic, with high maternal BMI, and had severe anemia as an indicator for transfusion. It was an attempt to perform intravascular transfusion when other common routes of fetal vascular access had failed. Results: There were 2 intrauterine deaths (25%), both of which were associated with in-utero transfusion and fulminant parvovirus B19 infection. The perinatal survival rate was 75% (6/8). Discussion: Fetal in-utero, intravascular transfusion by the intracardiac route may be used to correct severe early-onset anemia. It is particularly useful when technical issues of fetal size, early gestation (<20 weeks), maternal adiposity, and hydrops fetalis make umbilical cord or intrahepatic vein puncture technically difficult. Survival rates appear comparable to other series of pregnancies where in-utero transfusion is performed at early gestation.

Fetal blood sampling

OBJECTIVE

We sought to review indications, technical aspects, risks, and recommendations for fetal blood sampling (FBS).

METHODS

A systematic review was performed using MEDLINE, PubMed, EMBASE, and Cochrane Library using the terms "fetal blood sampling," "percutaneous umbilical blood sampling," and "cordocentesis." The search was restricted to English-language articles published from 1966 through July 2012. Priority was given to articles reporting original research, in particular randomized controlled trials, although review articles and commentaries also were consulted. Abstracts of research presented at symposia and scientific conferences were not considered adequate for inclusion in this document. Evidence reports and guidelines published by organizations or institutions such as the National Institutes of Health, Agency for Health Research and Quality, American Congress of Obstetricians and Gynecologists, and Society for Maternal-Fetal Medicine were also reviewed, and additional studies were located by reviewing bibliographies of identified articles. Grade (Grading of Recommendations Assessment, Development, and Evaluation) methodology was employed for defining strength of recommendations and rating quality of evidence. Consistent with US Preventive Task Force guidelines, references were evaluated for quality based on the highest level of evidence.

RESULTS AND RECOMMENDATIONS

Ultrasound-guided FBS is the only procedure that provides direct access to the fetal circulation. When invasive testing is planned for suspected severe fetal anemia or thrombocytopenia, we recommend FBS as the procedure of choice, with availability of immediate transfusion if confirmed. We recommend against the use of FBS for indications in which other less invasive, and therefore lower risk, alternatives are available. The overall success rate of FBS is high, and blood samples can be obtained in >98% of patients. We suggest that counseling for FBS include discussion about the potential risk of FBS that may include, but may not be limited to: bleeding from puncture site (20-30%); fetal bradycardia (5-10%); pregnancy loss (≥1.3%, depending on indication, gestational age, and placental penetration); and vertical transmission of hepatitis or human immunodeficiency virus. We recommend that FBS be performed by experienced operators at centers with expertise in invasive fetal procedures when feasible.

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.

Early intrauterine transfusion in severe red blood cell alloimmunization

OBJECTIVE

To determine perinatal outcome in pregnancies with early severe red blood cell (RBC) alloimmunization.

METHODS

This was a retrospective analysis of 30 patients requiring their first intrauterine transfusion (IUT) at < 22 weeks of gestation. Timing of the first IUT was based on evaluation of either the middle cerebral artery peak systolic velocity (MCA-PSV) or development of ascites.

RESULTS

Thirty-three per cent of the patients had experienced a previous intrauterine fetal death as a result of RBC alloimmunization. Of these alloimmunized pregnancies, 26 (87%) were associated with anti-D, four (13%) with anti-Kell and 12 had more than one antibody type involved. The antibody titers before the first IUT ranged from 1:128 to 1:8024. All fetuses were severely anemic before the first IUT with a median hemoglobin (Hb) level of 37 (range, 3-81) g/L. The nine hydropic fetuses had a lower Hb level compared with non-hydropic fetuses (median 15 g/L vs. 42 g/L, P = 0.016). However, 15 (71%) non-hydropic fetuses had an Hb level of < 50 g/L before the first IUT. The median gestational age at the first IUT was 20.4 (range, 16-22) weeks, and between one and nine transfusions were needed during pregnancy. Transfusion was via the intrahepatic vein (IHV) (n = 19), umbilical vein (n = 6) or umbilical artery (n = 2), or was intracardiac (n = 2) or intraperitoneal (n = 1). Overall perinatal survival rate was 80% and did not differ between hydropic and non-hydropic fetuses. Median gestation at delivery, after exclusion of six intrauterine fetal deaths, was 36.7 (range, 27.8-38.4) weeks.

CONCLUSIONS

In early severe RBC alloimmunization, fetuses can be severely anemic without hydrops, and prognosis cannot be predicted by the presence or absence of hydrops. Early IUT followed by serial transfusions is associated with a perinatal survival rate of about 80%.

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 cardiocentesis: a review of indications, risks, applications and technique

OBJECTIVES

To review the indications, applications and technique of fetal cardiocentesis.

METHODS

Review of published case reports and case series of fetal cardiocentesis utilizing the PubMed search engine of the National Library of Medicine.

RESULTS

Case reports and case series demonstrate that fetal cardiocentesis may be an alternative method by which to facilitate prenatal diagnosis, intravascular therapy, multifetal and selective fetal reduction and in utero therapy of congenital heart disease. However, procedure-associated risk is higher than with cordocentesis and may limit use of this procedure.

CONCLUSIONS

Fetal cardiocentesis may be a reasonable option to obtain fetal intravascular access and facilitate therapeutic interventions when cordocentesis fails or is not feasible. However, expected benefit must clearly outweigh the procedure-associated risk.

Intrahepatic vein for fetal blood sampling: one center's experience

OBJECTIVE

The objective of the study was to examine 1 center's experience with fetal blood sampling via the fetal intrahepatic vein (IHV) and cordocentesis.

STUDY DESIGN

Consecutive IHV and cordocentesis procedures between July 1987 and February 2006 were compared with respect to success rates, streaming at the sampling site, nonreassuring fetal heart rate (NRFHR), or need for urgent delivery post procedure. A subanalysis of cases with fetal thrombocytopenia was performed. Data were analyzed using Fisher's exact and Student t tests.

RESULTS

Two hundred ten procedures (130 IHV samplings and 110 cordocenteses) were identified. Success rates were significantly higher with IHV sampling than with cordocentesis (84.6% vs 69.1%, P = .004). Streaming from the sampling site occurred after 0.79% of IHV procedures vs 30.8% of cordocenteses (P < .0001). There was no difference between IHV and cordocentesis in the incidence of NRFHR or need for immediate delivery. Twenty-five cases of fetal thrombocytopenia (20 sampled via IHV, 5 by cordocentesis) were identified. Streaming from the sampling site occurred in 0 of 20 IHV cases vs 2 of 5 cordocentesis cases (40%) (P = .03).

CONCLUSION

IHV has a significantly lower rate of streaming from the sampling site, compared with cordocentesis. Our data suggest that IHV sampling conveys a particular advantage when fetal thrombocytopenia is suspected.

Fetal anaemia: diagnosis and management

Fetal anaemia can by treated by in-utero therapy, which results in a significant improvement in perinatal outcome. The important causes of fetal anaemia are rhesus alloimmunisation, kell alloimmunisation and parvovirus infection. At-risk pregnancies require serial monitoring to ensure timely intervention with intrauterine transfusion. Non-invasive testing with middle cerebral artery Doppler is becoming the monitoring modality of choice.