First intrauterine transfusion in Rh isoimmunised triplet pregnancy

Abstract

G3P2L1, 28+4 weeks of gestation rhesus (Rh) isoimmunised pregnant women, was referred with trichorionic triamniotic triplet pregnancy with Rh antibody titres of 1:32. Nuchal translucency and anomaly scan were within normal limits with no major malformation for any of the fetuses. Obstetric colour Doppler with middle cerebral artery peak systolic volume revealed foetal anaemia in all three fetuses having velocities corresponding to around 1.5 times the median. Decision of intrauterine transfusion of blood to all three fetuses was taken. Access to fetuses was challenging and expertise in interventional ultrasound was required for transfusion. The patient tolerated the procedure well and eventually went on to deliver uneventfully at 34 weeks of gestation for worsening pre-eclampsia. After birth, all three triplets received triple-surface intensive phototherapy and intravenous immunoglobulin at a dosage of 1 g/kg. Phototherapy was gradually reduced and discontinued within 72 hours, and the infants were discharged from the neonatal intensive care unit at 96 hours of age.

Background

Rhesus isoimmunisation leads to significant perinatal complications, including in utero anaemia, hydrops, foetal demise, as well as postnatal issues like hyperbilirubinaemia and cardiac failure.¹ Intrauterine blood transfusion stands as the sole established life-saving treatment. It is worth noting that the occurrence of isoimmunisation severe enough to necessitate intrauterine transfusions in multifoetal pregnancies is rare and presents a formidable challenge.¹ Although there are a few documented cases of intrauterine transfusions in twins in the literature, as far as we are aware, there have been no reports of intrauterine transfusions in triplets for rhesus (Rh) isoimmunisation.

The challenges faced during intrauterine transfusion (IUT) in multifoetal pregnancies arise from various factors. These include the uncertainty or variations in chorionicity, the presence of intraplacental anastomoses between vessels, varying degrees of anaemia among the fetuses, the complexity of establishing a clear cord-fetus relationship and difficulties in accessing the placental insertion site due to crowding by multiple foetal parts. Additional obstetric risks of prematurity, preterm rupture of membranes, chorioamnionitis, subsequent development of pre-eclampsia due to hyperplacentosis and procedure-related complications due to prolonged intervention to three fetuses are expected.

This report describes the management of a novel case of Rh isoimmunised trichorionic triamniotic triplets all of whom received intrauterine transfusion in utero with favourable outcome. The rise in twin births, driven by the increased use of assisted reproduction techniques, suggests that there will likely be a growing number of women with twin or triplet pregnancies who develop Rh isoimmunisation in the near future. Therefore, it becomes imperative to report and share initial experiences in managing these cases.

Case presentation

A woman in her third pregnancy (G3), having had two previous pregnancies (P2) and one live birth (L1), was referred at 28 weeks and 4 days of gestation with triplets. She was referred for evaluation and treatment after an ultrasound indicated severe anaemia in all three fetuses. The middle cerebral artery peak systolic velocity (MCA PSV) readings corresponded to 1.5 times the Median for further assessment and intervention.

The patient was asymptomatic and had no history of significant medical or surgical illnesses. In terms of her obstetric history, she had two full-term vaginal deliveries. The first delivery resulted in a healthy female child with no notable antenatal or postnatal issues. However, during her second pregnancy, she delivered a term neonate who developed severe jaundice on the third day of life and unfortunately passed away on the fourth day. It is important to note that anti-D immunoglobulin was not administered after either of her deliveries, which placed her at a high risk of sensitisation. Present pregnancy was spontaneous and no family history of twins and triplets.

On examination, the patient was normotensive and her general examination was unremarkable. Uterus was over-distended with multiple foetal parts palpable with all three distinct foetal heart sounds heard.

Investigations

At the time of referral, the patient had already undergone extensive investigations. Antenatal blood profile was within normal limits with normal nuchal translucency and no malformations in all the fetuses. The patient has a blood group of O−ve, and her indirect Coombs test was positive. Furthermore, her Rh antibody titres were notably high at 1:64, surpassing critical levels. It is worth noting that her husband had a blood group of O+ve. His zygosity was determined and was found to be homozygous which indicated that all fetuses would be rhesus positive.

Ultrasound examination revealed trichorionic triamniotic triplets with all three fetuses in cephalic presentation with normal growth and expected birth weights around 1000 g with MCA PSV in zone A (between 1.4 and 1.5 times the median (MOM)) suggesting severe foetal anaemia in all the fetuses with no signs of hydrops. Table 1 shows serial monitoring of MCA PSV in the three fetuses from 23 weeks onwards which revealed an increasing trend and at 28 weeks, all fetuses developed significant anaemia requiring transfusion (figure 1). Donor blood was tested for haemoglobin, haematocrit, blood group and type along with infection screening for HIV, hepatitis B surface antigen, hepatitis C virus, Treponema pallidum, cytomegalovirus (CMV) and malaria by our transfusion medicine department. Donor blood was crossmatched with the mother and doubly packed.

Table 1.

Triplet non-invasive monitoring by middle cerebral artery peak systolic velocity (MCA PSV) for foetal anaemia throughout pregnancy

		23+6 weeks	24+4 weeks	25+4 weeks	26+3 weeks	27+3 weeks	28+3 weeks	28+6 weeks	30+5 weeks	31+6 weeks	32+6 weeks	33+2 weeks
Triplet 1	MCA PSV	37	37	38	42	44	56	50	38	43	48	50
	MOM	1.2	1.1	1.1	1.2	1.2	1.5	1.3	<1	<1	1.0	1.1
Triplet 2	MCA PSV	37	37	37	41	46	56	45	32	45	52	54
	MOM	1.2	1.1	1.1	1.1	1.2	1.5	1.1	<1	1.0	1.1	1.2
Triplet 3	MCA PSV	29	37	32	40	38	53	48	29	54	55	56
	MOM	<1	1.1	<1	1.1	1	1.4	1.2	<1	1.2	1.1	1.5

MCA PSV, middle cerebral artery peak systolic velocity; MOM, multiples of the median.

Figure 1.

Trends in MCA PSV in all three triplets pretransfusion and post-transfusion. Bansal, Vandana; Gangurde, Akshaykumar. MCA PSV, middle cerebral artery peak systolic velocity.

The decision to perform intrauterine transfusions for all three triplets in a single session was made with the intention of minimising the number of procedures, reducing overall risk and cost and efficiently using the same blood, divided into three portions for each of the babies. In a triplet gestation, our concerns centred around the challenges of determining which cord should be assigned to each fetus, the limited space for the intervention due to the crowded uterine environment, as well as the potential risks associated with prolonged operative time, including the heightened risk of preterm or premature rupture of membranes and the development of chorioamnionitis.

Treatment

A paralysing agent (pancuronium 0.1 mg/kg estimated body weight of individual triplets) was given intramuscular simultaneously to all three foetal gluteal muscles. Pancuronium causes neuromuscular blockade causing reduced foetal movements and foetal heart rate variability during the procedure. Its duration of action is around 220 min. Pretransfusion haematocrit of all the fetuses was assessed and the same is mentioned in table 2. Guided by ultrasound, intrauterine intravascular transfusions were performed for all three triplets using double-packed (haematocrit of 75%) fresh O–ve blood, which was leucodepleted, CMV−ve, gamma irradiated and cross-matched with the mother’s blood. The transfusions were administered at the placental cord insertion site.¹ The amount of blood transfused to each triplet was determined based on factors including the initial foetal haematocrit, donor haematocrit, estimated foetal weight and fetoplacental blood volume, employing the Moise et al calculation.² The objective was to achieve a target haematocrit of 45%–50% by the end of the procedure. Approximately 70, 60 and 50 mL of blood were transfused to the three fetuses, respectively, resulting in a noticeable improvement in post-transfusion haematocrit levels. Subsequent monitoring of MCA PSV was conducted (figure 1; table 2).

Table 2.

Correlation of foetal haematocrit of preintrauterine and post-intrauterine transfusion and middle cerebral artery peak systolic velocity (MCA PSV) and effect of volume transfused

Case	Triplet		HB (gm%)	Haematocrit (%)	MCA PSV (cm/s)	Volume given (mL)
28+3 weeks	1	Pre-IUT	10.6	32	56	70
		Post-IUT	21.6	65.4	38
	2	Pre-IUT	10.9	33	56	60
		Post-IUT	–	–	32
	3	Pre-IUT	11	33	53	50
		Post-IUT	20.7	62.5	29

IUT, intrauterine transfusion; MCA PSV, middle cerebral artery peak systolic velocity.

In the case of triplets, the crowded uterine environment posed technical challenges when it came to identifying and assigning the correct cord to each fetus during the transfusion. However, diligent efforts were made to trace each cord to its respective fetus. Additionally, repositioning the patient into both the right and left lateral positions facilitated better access to the cord insertions. Overall, the intrauterine transfusion procedure played a crucial role in extending the pregnancy by an additional 5 weeks, while allowing for non-invasive monitoring via MCA PSV.

Outcome and follow-up

She had a caesarean section at 34 weeks due to severe pre-eclampsia while carrying triplets. Before the delivery, she received steroids and magnesium sulphate treatment. Triplet 3 had an MCA PSV of 1.5 MOM. Three male babies were born, weighing 1.5, 1.4 and 1.6 kg, respectively. In the neonatal intensive care unit (NICU) after birth, all three triplets received triple-surface intensive phototherapy and intravenous immunoglobulin (IVIG) at 1 g/kg. This treatment occurred after confirming that their serum bilirubin levels were within the phototherapy range but not high enough to require an exchange transfusion. Phototherapy was gradually reduced and completely stopped within 72 hours, and all three babies were discharged from the NICU after 96 hours of life (table 3). Timely correction of foetal anaemia prevented hydrops, extended the pregnancy to 34 weeks ¹ and eliminated the need for postnatal exchange transfusion.

Table 3.

Neonatal outcome in the triplet in relation to the timing of delivery, time since transfusion, middle cerebral artery peak systolic velocity (MCA PSV) just prior to delivery and postnatal parameters

Case	Age at delivery	Time since the last transfusion	MCA PSV	Weight	Apgar	HB	Bilirubin	Phototherapy	IV IG	Exchange transfusion	Top up transfusion	NICU stay
1/1	33+4	5 weeks	50	1460	8	17.8	6.3	+	+	–	–	96 hours
1/2	33+4	5 weeks	54	1430	9	18.1	5.2	+	+	–	–	96 hours
1/3	33+4	5 weeks	56	1590	8	16.9	4.4	+	+	–	–	96 hours

MCA PSV, middle cerebral artery peak systolic velocity; NICU, neonatal intensive care unit.

At 1 and 6 months of follow-up, all triplets were doing well and gaining weight. Hearing assessment (BERA) and neurological examination were normal. None of the babies required top up blood transfusion at follow-up.

Discussion

The incidence of Rh isoimmunisation has markedly decreased due to the widespread adoption of prenatal and postnatal anti-D immunoglobulin prophylaxis in Rh−ve pregnant women. Nevertheless, as assisted reproduction techniques become more prevalent, we anticipate a rise in the number of women with twin or triplet pregnancies who develop Rh isoimmunisation in the near future.¹

While the technique of intrauterine transfusion itself has not undergone significant changes, the management of pregnancies requiring this procedure has evolved considerably over the past three decades. There have been very limited documented cases in the literature that describe intrauterine foetal blood transfusion in twin pregnancies. A meta-analysis conducted by Manning et al up until 1985 reviewed 15 sets of twins complicated by Rh alloimmunisation. During that period, the only twin pair that survived received 15 amniocentesis procedures and eight intrauterine transfusions.³ Most of these cases involved intraperitoneal transfusions, assisted by X-rays or low-resolution ultrasound. However, advancements in ultrasound technology, offering better resolution for guiding invasive procedures, and the refinement of the transfusion technique through extensive clinical experience have significantly improved success rates. In particular, direct intravascular foetal transfusion has largely replaced the intraperitoneal technique due to the variable absorption rates associated with intraperitoneal transfusion, which relies on the transport of transfused red cells from the peritoneal cavity through the lymphatic system to the foetal circulation. In the case of our triplets who received simultaneous intravascular intrauterine transfusions, all three survived with only a single procedure. They were subsequently monitored non-invasively using middle cerebral artery peak systolic velocity.¹

The availability of non-invasive techniques for assessing foetal anaemia through Doppler evaluation of MCA PSV has significantly reduced the need for invasive procedures per patient. A groundbreaking study conducted by Mari et al in 1995 demonstrated that MCA PSV, when elevated above 1.5 MOM, is an extremely accurate method for diagnosing foetal anaemia non-invasively. This method boasts a sensitivity of nearly 100% with a false positive rate of only 12%.⁴ Subsequently, Oepkes et al confirmed the superiority of MCA PSV over amniotic fluid OD450, rendering serial amniocenteses for foetal anaemia screening essentially obsolete.⁵ However, in multifoetal gestations like triplets, obtaining the ideal angle of insonation for the MCA PSV assessment, close to 0 degrees, can be challenging due to limited space for manoeuvering.

In the context of the first immunised pregnancy, it is commonly believed that Rh antibody titres are closely associated with the severity of the disease.⁶ However, in cases like our patient, where Rh titres are elevated above the critical level due to a previously affected pregnancy, these titres may not effectively correlate with foetal haematocrit levels. Consequently, they may not provide a reliable means of assessing the severity of foetal involvement or determining the optimal timing for a transfusion. Nevertheless, elevated titres can serve as a valuable indicator for timely referral to specialised foetal therapy centres for comprehensive institutional management. In multifoetal pregnancies with Rh sensitisation, particularly when there is a history of previous foetal involvement, it may be prudent to initiate monitoring of middle cerebral artery peak systolic values as early as 18 weeks. This proactive approach ensures that potential issues are detected and managed promptly.

While it was anticipated that the Rh antibodies crossing the placenta in a pregnant woman carrying triplets would affect all three fetuses similarly, it was observed that there were differing impacts on each co-triplet, resulting in varying haemoglobin levels. These discrepancies in the severity of foetal anaemia, the extent of haemolysis and the diverse foetal responses underscore the necessity of individualised management for each fetus in a twin or triplet pregnancy.

Technique of intrauterine transfusion

IUT is the preferred treatment for foetal anaemia and becomes necessary when certain criteria are met. These criteria include an MCA PSV reading above 1.5 MOM, indicating severe foetal anaemia, the development of immune hydrops or a foetal haematocrit level below 30%, while the fetus is not yet mature enough for delivery (prior to 35 weeks of gestation). There are two commonly employed sites for direct vascular access during IUT: the intrahepatic portion of the umbilical vein or the umbilical vein at the cord insertion site into the placenta. The choice between these sites depends on the operator’s preference and experience. Abassi, in his clinical experience, found intrahepatic transfusion to be particularly useful in cases of multiple pregnancies or during advanced gestation when the placenta is located posteriorly.⁷ We were able to transfuse all our triplets through the placental cord insertion by positioning the mother laterally in two of the three triplets.

Chorionicity is a critical consideration in the antenatal management of Rh alloimmunisation. In cases of dichorionic or trichorionic twin or triplet pregnancies, where each fetus has its own placenta, it is essential to treat each fetus as a distinct individual. A notable study from France focused on Rh isoimmunised twin pregnancies, encompassing nine cases managed between 1987 and 1996. Of these pregnancies, eight were dizygotic, and in three instances, the foetal blood groups were found to be different.⁸ In situations where the foetal blood group is unknown, as was the case with our triplet set, it is advisable to administer O−ve blood to all the fetuses before conducting the transfusion. This precaution helps mitigate the risk associated with blood group incompatibility and ensures the safety of the transfusion procedure.

The incidence of procedure-related foetal loss during intrauterine transfusion varies, ranging from 0.9% to 4.9% per procedure. This risk is more closely associated with factors such as the presence of foetal hydrops, the gestational age at the time of transfusion, the severity of foetal anaemia and the experience of the operator.⁹ In the case of triplets, while the specific risk has not been calculated, it is reasonable to assume that it could be more than double the risk observed in singleton pregnancies. This higher risk is due to the need for triple transfusions, the technical challenges posed by multifoetal pregnancies and the inherent risk in twins/triplets of preterm labour and premature rupture of membranes. It is noteworthy that in our triplet transfusion procedure, we did not encounter any complications during the transfusion or within the 4 weeks following it, which is a positive outcome.

Numerous studies have highlighted poorer outcomes after IUT in hydropic fetuses, with a survival rate of approximately 78%, compared with non-hydropic fetuses. This discrepancy in outcomes may be attributed to the reduced cardiac reserve and heightened susceptibility to volume overload in hydropic fetuses.^{10 11} Early detection and treatment to prevent foetal hydrops could potentially lead to improved survival rates and better long-term outcomes.

Typically, a repeat transfusion is required within 1 to 2 weeks, and the timing is determined by observing a 1% drop in haematocrit per day from the final post-transfusion haematocrit or when the MCA PSV reaches 1.5 MOM again. Alternatively, the timing of the next transfusion can be calculated based on the expected decline in foetal haemoglobin, with rates of 0.4, 0.3 and 0.2 g/L/day used for the first, second and third IUT intervals, respectively.¹² In the case of all our triplet fetuses, the decrease in haemoglobin values was considerably less than expected, allowing us to extend the pregnancy for nearly 5 weeks without requiring a repeat transfusion.

Performing the procedure in one sitting can have several advantages. It helps reduce the risk associated with multiple and frequent procedures, minimises the discomfort and stress for the patient, and can be more cost-effective since it allows for the efficient use of the same cross-matched blood, divided into three portions, for all the fetuses. This approach can enhance the overall management of multifoetal pregnancies, such as triplets, by streamlining the process and optimising resource utilisation.

Delivery and postnatal outcome

Regrettably, there is a lack of high-quality data that can provide clear guidance on the optimal timing of delivery for fetuses receiving in utero therapy for anaemia. In many medical centres, foetal transfusions are typically performed up to 35 weeks of gestation. However, in singleton pregnancies, delivery is often planned for 37 to 38 weeks. This decision is based on a delicate balance between the risks associated with stillbirth, the consequences of foetal anaemia and the potential risks of additional intrauterine transfusions vs the risks associated with prematurity and the potential complications of anaemia and hyperbilirubinaemia if delivery occurs before term.¹³ In the case of multifoetal pregnancies, such as twins or triplets, additional factors come into play. These include the inherent risks associated with twin/triplet transfusion procedures, an increased baseline risk of preterm labour and premature rupture of membranes, and the potential development of pre-eclampsia due to hyperplacentosis, which can result in Mirror syndrome. Given these added risks, our decision to deliver the Rh isoimmunised triplets at 34 weeks, following steroid administration for lung maturity, was likely made to prioritise the overall health and well-being of both the mother and the fetus.

Indeed, in cases involving pregnancies complicated by alloimmune anaemia, it is of paramount importance to involve neonatal services early in the care of these patients. This proactive approach ensures that preparations are made for delivery, including having blood for transfusion readily available if needed. Furthermore, having the appropriate personnel present at the time of delivery is essential to optimise the neonatal management of alloimmune anaemia, thereby enhancing the chances of a successful outcome for both the mother and the newborn.

During the intrauterine period, foetal hyperbilirubinaemia is typically managed by the maternal system. However, after delivery, the neonatal hepatic system may become overwhelmed by the excess bilirubin that needs to be metabolised, potentially leading to kernicterus. In this scenario, the standard treatment for hyperbilirubinaemia involves phototherapy followed by a double-volume exchange transfusion. It is noteworthy that the more intrauterine transfusions performed, the less severe the postnatal hyperbilirubinaemia tends to be, and the longer the suppression of erythropoiesis can be maintained. In our case, all three surviving neonates required double-surface phototherapy, but none needed an exchange transfusion.¹ The use of IVIG in our neonatal ICU is a preferred modality to reduce the need for exchange transfusion, and it was administered to all three fetuses to manage hyperbilirubinaemia effectively.

Neonatal survival rates in the era of IUT are as follows: 84% overall, 70% for hydropic fetuses and 94% for non-hydropic fetuses.⁷ Neonatal survival in our triplets was good with minimal morbidity.

Benefits noted in our case

• Prolonging the pregnancy by 5 weeks (29 to 34 weeks), thereby reducing problems of prematurity.

• Timely reversal of anaemia by IUT; none of the fetuses showed hydropic changes.

• No need for postnatal exchange transfusion.

• No adverse neurological sequelae; normal hearing at 1-month follow-up.

• No need for top-up blood transfusion at 1-month follow-up.

Learning points.

• Performing intrauterine transfusion in triplets presents a formidable challenge that necessitates a high level of expertise and the involvement of an experienced fetomaternal medicine specialist. The complexities encountered during IUT in multifoetal gestations stem from various factors, including the ambiguity surrounding chorionicity, the presence of intraplacental anastomoses between vessels, variations in the degree of anaemia among the fetuses, the intricate task of determining the cord-fetus relationship and the formidable challenge of reaching the placental insertion site due to the crowded uterine environment created by multiple foetal parts.

• IUT is safe and effective in multiple pregnancies and may help prolong the pregnancy.

• Despite shared exposure to same concentration of maternal rhesus antibody, varying degree of foetal anaemia may be expected in triplets.

Ethics statements

Patient consent for publication

Consent obtained directly from patient(s).