Neonatal and Obstetrical Outcomes of Pregnancies Complicated by Alloimmunization.

BACKGROUND AND OBJECTIVES: Despite advances in the prevention of rhesus (Rh)(D) alloimmunization, alloantibodies to Rh(D) and non-Rh(D) red blood cell antigens continue to be detected in ∼4% of US pregnancies and can result in hemolytic disease of the fetus and newborn (HDFN). Recent reports on HDFN lack granularity and are unable to provide antibody-specific outcomes. The objective of this study was to calculate the frequency of alloimmunization in our large hospital system and summarize the outcomes based on antibody specificity, titer, and other clinical factors. METHODS: We identified all births in a 6-year period after a positive red blood cell antibody screen result during pregnancy and summarized their characteristics and outcomes. RESULTS: A total of 707 neonates were born after a positive maternal antibody screen result (3.0/1000 live births). In 31 (4%), the positive screen result was due to rhesus immune globulin alone. Of the 676 neonates exposed to alloantibodies, the direct antibody test (DAT) result was positive, showing antigen-positivity and evidence of HDFN in 37% of those tested. Neonatal disease was most severe with DAT-positive anti-Rh antibodies (c, C, D, e, E). All neonatal red blood cell transfusions (15) and exchange transfusions (6) were due to anti-Rh alloimmunization. No neonates born to mothers with anti-M, anti-S, anti-Duffy, anti-Kidd A, or anti-Lewis required NICU admission for hyperbilirubinemia or transfusion. CONCLUSIONS: Alloimmunization to Rh-group antibodies continues to cause a majority of the severe HDFN cases in our hospital system. In neonates born to alloimmunized mothers, a positive DAT result revealing antigen-positivity is the best predictor of anemia and hyperbilirubinemia.

Can Red Blood Cell and Platelet Transfusions Have a Pathogenic Role in Bronchopulmonary Dysplasia?

OBJECTIVE: To evaluate whether transfusions in infants born preterm contribute to the pathogenesis of bronchopulmonary dysplasia (BPD). STUDY DESIGN: We conducted a multihospital, retrospective study seeking associations between red blood cell or platelet transfusions and BPD. We tabulated all transfusions administered from January 2018 through December 2022 to infants born ≤29 weeks or <1000 g until 36 weeks postmenstrual age and compared those with BPD grade. We performed a sensitivity analysis to assess the possibility of a causal relationship. We then determined whether each transfusion was compliant with restrictive guidelines, and we estimated effects fewer transfusions might have on future BPD incidence. RESULTS: Eighty-four infants did not develop BPD and 595 did; 352 developed grade 1 (mild), 193 grade 2 (moderate), and 50 grade 3 (severe). Transfusions were given at <36 weeks to 7% of those who did not develop BPD, 46% who did, and 98% who developed severe BPD. For every transfusion the odds of developing BPD increased by a factor of 2.27 (95% CI, 1.59-3.68; P < .001). Sensitivity analyses suggested that transfusions might contribute to BPD. Fifty-seven percent of red blood cell transfusions and 68% of platelet transfusions were noncompliant with new restrictive guidelines. Modeling predicted that complying with restrictive guidelines could reduce the transfusion rate by 20%-30% and the moderate to severe BPD rate by ∼4%-6%. CONCLUSIONS: Transfusions were associated with BPD incidence and severity. Lowering transfusion rates to comply with current restrictive guidelines might result in a small but meaningful reduction in BPD rates.

Banked term umbilical cord blood to meet the packed red blood cell transfusion needs of extremely-low-gestational-age neonates: a feasibility analysis.

OBJECTIVES: To assess the feasibility of drawing, processing, safety-testing, and banking term umbilical cord blood to meet the packed red blood cell transfusion (RBC Tx) needs of extremely-low-gestational-age neonates (ELGANs). DESIGN: (1) Retrospectively analyze all ELGANs RBC Tx over the past three years, (2) Estimate local cord blood availability, (3) Assess interest in this project, and implementation barriers, through stakeholder surveys. RESULTS: In three years we cared for 266 ELGANs; 165 (62%) received ≥1 RBC Tx. Annual RBC Tx averaged 197 (95% CI, 152-243). If 10% of our 10,353 annual term births had cord blood drawn and processed, and half of those tested were acceptable for Tx, collections would exceed the 95th % upper estimate for need by >four-fold. Interest exceeded 97%. Identified barriers included FDA approval, training to collect cord blood, and cost. CONCLUSION: RBC Tx needs of ELGANS could be met by local cord blood collection.

Associations between blood donor sex and age, and outcomes of transfused newborn infants.

BACKGROUND: It is controversial whether the sex or age of red blood cell (RBC) donors affects mortality or morbidities of transfused newborn infants. We assessed these issues using a multi-year, multi-hospital database linking specific outcomes of neonatal transfusion recipients with RBC donor sex and age. STUDY DESIGN AND METHODS: We performed retrospective analyses of all neonates receiving ≥ one RBC transfusion during a 12-year period in all Intermountain Healthcare hospitals, matching mortality and specific morbidities of each transfusion recipient with the sex and age of each donor. RESULTS: There were 6396 RBC transfusions administered to 2086 infants in 15 hospitals. A total of 825 infants were transfused exclusively with RBC from female donors, 935 infants were transfused exclusively with RBC from male donors, and 326 infants were transfused with RBC from both female and male donors. No differences in baseline characteristics were identified among the three groups. Infants who received blood from both male and female donors had more RBC transfusions (5.3 ± 2.9 transfusions if received both male and female donor blood vs. 2.6 ± 2.2 if received blood from only one sex, mean ± SD, p < .001). We identified no significant differences in mortality or morbidities associated with the sex or the age of blood donors. Similarly, an analysis of matched vs. mismatched donor/recipient sex revealed no associations with death or neonatal morbidities. CONCLUSION: These data support the practice of transfusing newborn infants with RBC obtained from donors of either sex and regardless of donor age.

Diagnosing Anemia in Neonates: An Evidence-Based Approach.

It is important for clinicians who render neonatal care to precisely and reproducibly diagnose anemia; however, confusion arises from various definitions. For the simplicity and consistency of detection, we advocate defining neonatal anemia as a hemoglobin level or hematocrit below the 5th percentile of the reference population, which is highly dependent on gestational and postnatal ages. Thus, a newborn infant delivered at 24 weeks' gestation will have anemia with a blood hemoglobin concentration much lower than a hemoglobin concentration defining anemia at term. Moreover, a hemoglobin concentration defining anemia at term birth is higher than that defining anemia in the same infant 60 days after birth. Diagnosing neonatal anemia can be evidence-based and consistent by using reference intervals derived from large neonatal databases. To do this, we advocate defining anemia as a hemoglobin level that plots below the 5th percentile lower reference interval, defining moderately severe anemia as a hemoglobin value between the 1st and 5th percentile, and defining severe anemia as a hemoglobin level that plots below the 1st percentile. The information provided in this review can easily be adopted by clinical laboratories and individual neonatal care units, thereby fostering application of these definitions for all infants whose hemoglobin levels are measured. Additional normative values included in this review describing various other erythrocyte metrics can likewise be easily adopted. Doing so will codify and standardize the diagnosis of neonatal anemia and will facilitate identifying the cause of the anemia, thus pointing the way to proper additional diagnostic testing and treatment.

Platelet Transfusions in a Multi-Neonatal Intensive Care Unit Health Care Organization Before and After Publication of the PlaNeT-2 Clinical Trial.

OBJECTIVES: To evaluate whether implementing more restrictive neonatal intensive care unit (NICU) platelet transfusion guidelines following the Platelets for Neonatal Transfusion - Study 2 randomized controlled trial (transfusion threshold changed from 50 000/µL to 25 000/µL for most neonates) was associated with fewer NICU patients receiving a platelet transfusion, without adversely affecting outcomes. STUDY DESIGN: Multi-NICU retrospective analysis of platelet transfusions, patient characteristics, and outcomes during 3 years before vs 3 years after revising system-wide guidelines. RESULTS: During the first period, 130 neonates received 1 or more platelet transfusions; this fell to 106 during the second. The transfusion rate was 15.9/1000 NICU admissions in the first period vs 12.9 in the second (P = .106). During the second period, a smaller proportion of transfusions was administered when the platelet count was in the 50 000-100 000/µL range (P = .017), and a larger proportion when it was <25 000/µL (P = .083). We also saw a fall in the platelet counts that preceded the order for transfusion from 43 100/µL to 38 000/µL (P = .044). The incidence of adverse outcomes did not change. CONCLUSIONS: Changing platelet transfusion guidelines in a multi-NICU network to a more restrictive practice was not associated with a significant reduction in number of neonates receiving a platelet transfusion. The guideline implementation was associated with a reduction in the mean platelet count triggering a transfusion. We speculate that further reductions in platelet transfusions can safely occur with additional education and accountability tracking.

Placental abruption and neonatal anemia.

OBJECTIVE: Placental abruption can cause maternal blood loss and maternal anemia. It is less certain whether abruption can cause fetal blood loss and neonatal anemia. STUDY DESIGN: Retrospective multi-hospital 24-month analysis of women with placental abruption and their neonates. RESULTS: Of 55,111 births, 678 (1.2%) had confirmed abruption; 83% of these neonates (564) had one or more hemoglobins recorded in the first day. Four-hundred-seventy (83.3%) had a normal hemoglobin (≥5th% reference interval) while 94 (16.7%) had anemia, relative risk 3.26 (95% CI, 2.66-4.01) vs. >360,000 neonates from previous reference interval reports. The relative risk of severe anemia (<1st% interval) was 4.96 (3.44-7.16). When the obstetrician identified the abruption as "small" or "marginal" the risk of anemia was insignificant. CONCLUSIONS: Most abruptions do not cause neonatal anemia but approximately 16% do. If an abruption is not documented as small, it is important to surveille the neonate for anemia.

Neonatal subgaleal hemorrhage: twenty years of trends in incidence, associations, and outcomes.

BACKGROUND: In 2011, we reported 38 neonates with subgaleal hemorrhage (SH), relating an increasing incidence. It is unclear whether the incidence in our hospitals continued to rise and which risk factors and outcomes are associated with this condition. DESIGN: We retrospectively analyzed every recognized case of SH in our hospitals from the end of our previous report (2010) to the present (2022). We redescribed the incidence, scored severity, tabulated blood products transfused, and recorded outcomes. RESULTS: Across 141 months, 191 neonates were diagnosed with SH; 30 after vacuum or forceps. The incidence (one/1815 births) was higher than in our 2011 report (one/7124 births). Also, severe SH (requiring transfusion) was more common (one/10,033 births vs. one/20,950 births previously). Four died (all with severe SH) and 12 had neurodevelopmental impairment. CONCLUSION: Recognized cases of SH are increasing in our system without a clear explanation. Adverse outcomes are rare but continue to occur.

Severe Anemia at Birth-Incidence and Implications.

OBJECTIVE: To identify neonates with severe anemia at birth, defined by a hemoglobin or hematocrit value within the first 6 hours after birth that plotted below the 1st percentile according to gestational age. For each patient, we retrospectively determined whether caregivers recognized the anemia within the first 24 hours after birth and the probable cause and outcome of anemia. STUDY DESIGN: This was a retrospective cohort analysis of Intermountain Healthcare population-based data from neonates born between January 2011 and December 2020 who had a hemoglobin or hematocrit value measured within the first 6 hours after birth below the 1st percentile lower reference interval (hematocrit ∼35% in near-term/term neonates). RESULT: Among 299 927 live births, we identified 344 neonates with severe anemia at birth. In 191 of these neonates (55.5%), the anemia was recognized by caregivers during the first 24 hours. Anemia was more likely to be recorded as a problem (85%) if the hemoglobin was ≥2 g/dL below the 1st percentile (P < .001). The lowest hemoglobin values occurred in those in whom hemorrhage was the probable cause (P < .013 vs hemolysis and P < .001 vs hypoproduction, mixed cause, or indeterminant.) Treatment was provided to 39.5%. A retrospective review suggested that mixed mechanisms, particularly hemorrhagic plus hemolytic, occurred more commonly than was recognized at the time of occurrence. CONCLUSIONS: Severe anemia at birth often went unrecognized on the first day of life. Algorithm-directed retrospective reviews commonly identified causes that were not listed in the medical record. We postulate that earlier recognition and more accurate diagnoses would be facilitated by an electronic medical record-associated hemoglobin/hematocrit gestational age nomogram.

Nucleated Red Blood Cell Counts of Neonates Born Emergently 1-4 h after a Maternal Cardiac Arrest.

A high nucleated red blood cell (NRBC) count in a newborn infant at birth is sometimes used to imply that fetal hypoxia occurred. However, it is debated whether many hours are required between fetal hypoxia and the appearance of high NRBC or alternatively, whether this can occur very quickly, with fetal hypoxia within minutes to a few hours before birth. We sought relevant information from four unfortunate cases, where during a previously healthy pregnancy, the mother had a sudden cardiac arrest, with cardiopulmonary resuscitation begun at the incident scene and continued through emergent cesarean section delivery.

Fetomaternal hemorrhage: Evidence from a multihospital healthcare system that up to 40% of severe cases are missed.

BACKGROUND: We previously reported fetomaternal hemorrhage (FMH) in 1/9160 births, and only one neonatal death from FMH among 219,853 births. Recent reports indicate FMH is not uncommon among stillbirths. Consequently, we speculated we were missing cases among early neonatal deaths. We began a new FMH initiative to determine the current incidence. METHODS: We analyzed births from 2011 to 2020 where FMH was diagnosed. We also evaluated potential cases among neonates receiving an emergent transfusion just after birth, whose mothers were not tested for FMH. RESULTS: Among 297,403 births, 1375 mothers were tested for FMH (1/216 births). Fourteen percent tested positive (1/1599 births). Of those, we found 25 with clinical and laboratory evidence of FMH adversely affecting the neonate. Twenty-one received one or more emergency transfusions on the day of birth; all but two lived. We found 17 others who received an emergency transfusion on the day of birth where FMH was not tested for, but was likely; eight of those died. The 42 severe (proven + probable) cases equate to 1/7081 births. We judged that 10 of the 42 had an acute FMH, and in the others it likely had more than a day before birth. CONCLUSIONS: We estimate that we fail to diagnose >40% of our severe FMH cases. Needed improvements include (1) education to request maternal FMH testing when neonates are born anemic, (2) education on false-negative FMH tests, and (3) improved FMH communications between neonatology, obstetrics, and blood bank.

Neonatal Reference Intervals for the Complete Blood Count Parameters MicroR and HYPO-He: Sensitivity Beyond the Red Cell Indices for Identifying Microcytic and Hypochromic Disorders.

OBJECTIVE: To create neonatal reference intervals for the MicroR and HYPO-He complete blood count (CBC) parameters and to test whether these parameters are sensitive early markers of disease at early stages of microcytic/hypochromic disorders while the CBC indices are still normal. STUDY DESIGN: We retrospectively collected the CBC parameters MicroR and HYPO-He, along with the standard CBC parameters, from infants aged 0-90 days at Intermountain Healthcare hospitals using Sysmex hematology analyzers. We created reference intervals for these parameters by excluding values from neonates with proven microcytic disorders (ie, iron deficiency or alpha thalassemia) from the dataset. RESULT: From >11 000 CBCs analyzed, we created reference intervals for MicroR and HYPO-He in neonates aged 0-90 days. The upper intervals are considerably higher in neonates than in adults, validating increased anisocytosis and polychromasia among neonates. Overall, 52% of neonates with iron deficiency (defined by reticulocyte hemoglobin equivalent <25 pg) had a MicroR >90% upper interval (relative risk, 4.14; 95% CI, 3.80-4.53; P < .001), and 68% had an HYPO-He >90% upper interval (relative risk, 6.64; 95% CI, 6.03-7.32; P < .001). These 2 new parameters were more sensitive than the red blood cell (RBC) indices (P < .001) in identifying 24 neonates with iron deficiency at birth. CONCLUSIONS: We created neonatal reference intervals for MicroR and HYPO-He. Although Sysmex currently designates these as research use only in the US, they can be measured as part of a neonate's CBC with no additional phlebotomy volume or run time and can identify microcytic and hypochromic disorders even when the RBC indices are normal.

A New Hour-Specific Serum Bilirubin Nomogram for Neonates ≥35 Weeks of Gestation.

OBJECTIVE: To develop a statistically rigorous, hour-specific bilirubin nomogram for newborns based on a very large data set; and use it prospectively as a replacement for the 1999 Bhutani nomogram. STUDY DESIGN: This was a retrospective analysis of first total serum bilirubin (TSB) measurements from 15 years of universal bilirubin screening during birth hospitalizations at 20 Intermountain Healthcare hospitals. Hour-specific TSB values were assembled into a nomogram by percentile, and subgroups were compared. RESULTS: The information obtained included robust data in the first 12 hours after birth (which was not included in the 1999 nomogram), general agreement with the 1999 nomogram for values in the first 60 hours, but higher 75th and 95th percentile TSB values thereafter in the new version, no difference in TSB between male and female infants, higher TSB values among earlier gestation neonates (350/7-366/7 weeks vs ≥37 weeks, P < .0001), and lower TSB values in neonates of Black race (P < .0001) and higher values in neonates of Asian race (P < .001). CONCLUSIONS: An updated and more informative Bhutani neonatal bilirubin nomogram, based on 140 times the number of subjects included the 1999 version, is now in place in our health care system.

Early Hyperbilirubinemia in Neonates with Down Syndrome.

OBJECTIVE: To compare total serum bilirubin (TSB) levels, phototherapy usage, and hospital readmission for jaundice among neonates with Down syndrome vs controls. STUDY DESIGN: A retrospective cohort study using 15 years of multihospital data. We created control reference intervals (5th, median, and 95th percentiles) for initial TSB values hourly during the first days after birth, and determined the proportion of neonates with Down syndrome whose TSB exceeded the 95th percentile control interval. We determined the proportion with an initial TSB exceeding the upper control reference interval, the highest TSB recorded, the percentage of neonates receiving phototherapy, and the rate of hospital readmission for jaundice treatment. RESULTS: We compared 357 neonates with Down syndrome with 377 368 controls. Compared with controls, those with Down syndrome had 4.7 times the risk (95% CI, 3.9-5.7; P < .0001) of an initial TSB exceeding the 95th percentile control interval (23.5% vs 5.0%), 8.9 times (95% CI, 8.1-9.8; P < .0001) the phototherapy usage (62.2% vs 7.0%), and 3.6 times (95% CI, 1.6-8.2; P = .0075) the readmission rate for jaundice (17.4 vs 4.8 per 1000 live births). CONCLUSIONS: Neonates with Down syndrome have a substantial risk of early hyperbilirubinemia. The American Academy of Pediatrics currently advises obtaining an early screening complete blood count from neonates with Down syndrome. We submit that assessing their TSB is also advisable.

Neonates with suspected microangiopathic disorders: performance of standard manual schistocyte enumeration vs. the automated fragmented red cell count.

OBJECTIVES: To enhance the diagnosis of schistocyte-producing conditions, we compared routine manual schistocyte enumeration with automated fragmented red cell counts (FRCs). STUDY DESIGN: In neonates "suspected" of having sepsis, NEC, or DIC we compared manual schistocyte estimates vs. automated FRC counts. When the two disagreed, we used a "gold standard" from a  ≥ 1000 RBC differential. We also assessed the diagnostic accuracy of the FRC count in diagnosing sepsis, NEC, or DIC. RESULTS: We collected 270 CBCs from 90 neonates. The methods agreed in 63% (95% CI 55%-70%) of the CBCs. Among the 37% where they disagreed, the FRC count was more accurate in 100% (95% CI 88-100%). An elevated FRC count was specific for sepsis, and was sensitive and specific for necrotizing enterocolitis and DIC. CONCLUSIONS: Automated FRC counts have advantages over routine manual evaluation, larger sample size, lower expense, and superior accuracy in diagnosing schistocyte-producing conditions.