Antibodies In Pregnancy Research Articles

An Observational Study to Estimate the Prevalence of Subclinical Hypothyroidism and Anti-TPO Antibodies in Pregnancy and to Compare the Maternal and Fetal Outcomes with Euthyroid Cases

An Observational Study to Estimate the Prevalence of Subclinical Hypothyroidism and Anti-TPO Antibodies in Pregnancy and to Compare the Maternal and Fetal Outcomes with Euthyroid Cases

6938 An Unusual Case of New-onset autoimmune insulin dependent Diabetes Mellitus Complicating Gestational Diabetes Mellitus in A Pregnant Female Diagnosed Early Postpartum - The Enigma of Autoimmunity and Diabetes During Pregnancy

Abstract Disclosure: R. Abdelmasih: None. W. Pan: None. Introduction: Gestation diabetes is the most common metabolic disorder in pregnancy affecting 25% of pregnancies. T1DM accounts for 0.2-0.5% of all pregnancies in the United States yearly. New-onset autoimmune insulin-dependent diabetes mellitus during pregnancy is very uncommon and it might be overlooked. Diabetes-related autoantibodies have been studied in women with GDM with prevalence of 0-10%. There is controversial data regarding the clinical significance of checking diabetes antibodies in pregnancy. Case Presentation: A 22-year-old G1P1 female with history of Hashimoto hypothyroidism presented during early second trimester for evaluation of GDM with serum glucose of 300s mg/dl in a random blood sample with multiple subsequent high values, hemoglobin A1C of 9.4% (prepartum value was 5.3%). Patient was started on insulin during pregnancy. Pregnancy was complicated with cesarian section and macrosomia. 1 week postpartum, A1c was 5.4%, Insulin was discontinued, and patient was continued on Metformin. 2 months Postpartum, patient presented with persistent high blood glucose values of 300-400 mg/dl with no signs of DKA. Glipizide and Glargine 15 units daily were added though patient continued to have hyperglycemia. Laboratory workup were remarkable for high blood glucose of 342 mg/dl, low C peptide of 0.6 ng/dl, and positive glutamic acid decarboxylase antibodies (GAD Ab) 38.8 U/ml. oral antidiabetics were discontinued and prandial insulin was added. Discussion: GDM is a risk factor for DMII after pregnancy given high insulin resistance postpartum, Data regarding new-onset DMI and diabetes autoimmunity during pregnancy is lacking. About 0-10% of women with gestational diabetes develop DM autoantibodies. GAD Ab exhibits the highest sensitivity of 63% for type 1 diabetes prediction compared to Islet cell antibodies (48%), and tyrosine phosphatase-related islet antigen 2 (34%). Pathophysiology of autoimmune DM during pregnancy is not quite understood; It is thought that when autoimmune tendency is present, GDM causes β-cells to deteriorate due to excessive insulin production in setting of insulin resistance, and the burden of third-trimester gestation may cause the insulin deficiency to be expressed sooner than non-pregnant female. So far, Literature about the predictive value or specific clinical features of checking diabetes autoantibodies is discordant and inconclusive. It is suggested to screen for autoantibodies only when array of clinical hallmarks suggestive of an autoimmune DM form of GDM present as young age, low BMI, need for insulin therapy early in pregnancy, presence of ketones, concurrent other autoimmune conditions (e.g., thyroiditis). This case is to shed light on autoimmunity in pregnancy. More data is needed with longer follow-up to better identify women at risk, their characteristics, indications for autoantibodies testing, follow and prognosis. Presentation: 6/2/2024

The utility of phospholipase A2 receptor antibody in pregnancy: A case report

Primary membranous nephropathy remains a rare but challenging condition to manage in pregnancy. We present a case of an unplanned pregnancy in a 35-year-old woman with PLA2R-antibody positive membranous nephropathy, who had demonstrated serological response to rituximab given three months prior to pregnancy (PLA2R 115 IUmL reducing to 2 IU/mL, normal <13.9 IU/mL)). Throughout pregnancy, serial measurements of proteinuria and PLA2R-antibodies were used to understand disease activity and inform the decision to escalate treatment. Delivery of a healthy male infant occurred at 34 weeks, due to threatened pre-eclampsia and reduced fetal growth. There was evidence of trans-placental transfer of antibodies (15.2 IU/mL – normal <13.9 IU/mL) but no associated nephrotic syndrome in the infant. This case highlights the potential of PLA2R antibody as a diagnostic and monitoring tool during pregnancy, and adds to a small body of literature around the consequences of fetal–maternal transfer of the PLA2R antibody.

Anti-Kpb antibody in pregnancy

Anti-Kpb antibody in pregnancy

Performance of eight commercial immunoassays for the detection of cytomegalovirus-specific IgM antibodies in pregnancy - no test fits all needs.

Detection of cytomegalovirus (CMV)-specific immunoglobulin M (IgM) antibodies as first-line serologic diagnosis plays an important role in identifying CMV primary infection during pregnancy. The performance characteristics of eight commercially available CMV IgM assays were compared. Sensitivity and IgM antibody kinetics were assessed using 100 acute phase and follow-up sera from 39 pregnant women with a well-defined onset of CMV primary infection. Specificity was analyzed using 50 well-characterized serum samples from pregnant women not infected or latently infected with CMV and from patients with other acute infections. Until 12 weeks after the onset of primary infection, four assays showed sensitivities of 100%, whereas the others had individual gaps to detect all primary infections in this time period. All assays showed a time-dependent decrease of IgM levels. More than 12 weeks after the onset of infection, the IgM-positive rates varied considerably between tests. The specificity was between 92% and 98% in all but one assay. The observed differences in the performance characteristics must be taken into account in CMV screening and diagnosis of primary infection during pregnancy.

Rate of clinically significant red blood cell antibody seroconversion in pregnancy

Objective To determine the rate of clinically significant red blood cell (RBC) antibody seroconversion in pregnancy and associated risk factors and neonatal outcomes. Methods This is a retrospective cohort study of all deliveries within a large multi-hospital system from July 2016 to March 2023. Deliveries with a missing RBC antibody screen on admission for delivery were excluded, as were deliveries with a positive antibody screen on admission for delivery without a record of antecedent type and screen (T&S) in that pregnancy. Deliveries were categorized as 1) not possessing clinically significant antibodies (which includes those with a negative antibody screen, evidence of passive immunity solely due to Rh(D) immune globulin (RhIG), or possessing only non-clinically significant RBC antibodies); 2) previously alloimmunized (i.e. pregnancies that demonstrated clinically significant antibodies on the first T&S, regardless if they accrued additional antibodies throughout the pregnancy); or 3) seroconverted (i.e. no clinically significant antibodies on the first T&S with subsequent development of alloimmunization with clinically significant antibodies). For neonates born to seroconverted patients with clinically significant antibodies, neonatal outcomes such as initial hemoglobin, need for transfusion, and neonatal intensive care unit (NICU) admission were ascertained via chart abstraction. All records were linked with an existing validated database, inclusive of maternal characteristics and pregnancy outcomes, and comparisons were made between three categories based on antibody status with a sub-analysis of two categories. Bivariate analysis was performed with Chi-square for categorical and Wilcoxon rank-sum or Kruskal–Wallis test for continuous variables. Results There were 58,912 pregnant individuals with 71,384 eligible deliveries during the study period, with 67,570 deliveries remaining after data linkage. Of these, 67,209 (99.5%) deliveries had a negative or non-clinically significant antibody screen at delivery. Of the remaining 361 (0.53%) deliveries, 185 (0.27%) were previously alloimmunized and 176 (0.26%) seroconverted in pregnancy. Among pregnancies demonstrating seroconversion, the most common newly acquired antibodies were anti-E, anti-c, anti-JkA, anti-C, anti-D, anti-M, anti-K, and anti-S. Among the 176 pregnancies complicated by seroconversion, there were four unexplained fetal losses, none of which were attributable to HDFN. Among the 178 liveborn neonates born to the 176 pregnancies demonstrating seroconversion, three (1.7%) infants had initial hemoglobin <13.5 mg/dL, four (2.2%) required postnatal transfusion but all were unrelated to HDFN, and 34 (19.1%) required NICU admission. When comparing deliveries demonstrating seroconversion with those with a negative antibody screen at delivery, advanced maternal age and increasing gravidity and parity were most strongly associated with seroconversion. Conclusion Development of new clinically significant RBC antibodies in pregnancy occurred at a rate of 0.26% in this large cohort study with no cases of stillbirth or neonatal demise attributable to RBC alloimmunization among pregnancies demonstrating seroconversion. Advanced maternal age and increasing gravidity and parity were most strongly associated with seroconversion in pregnancy. Routine third trimester prenatal assessment of maternal antibody status may not be indicated due to low likelihood for clinically significant seroconversion.

Maternal Seroprevalence and Placental Transfer of COVID-19 Antibodies in Pregnancy: A Hospital-Based Study.

Coronavirus disease 2019 (COVID-19) is a relatively new disease with high morbidity and mortality.Information about the prevalence of infections in pregnancy could help identify herd immunity, project epidemics, and decide policy guidelines. The aim of this study was to determine the infection susceptibility risk of COVID-19 in pregnancy, to determine the prevalence of COVID-19 antibodies (IgG & IgM), and to evaluate the determinants of COVID-19 antibody positivity in pregnancy. This was an analytical cross-sectional study involving 258 consenting pregnant women recruited at Irrua Specialist Teaching Hospital, Edo State, Nigeria. Of these, 179 participants were recruited from the antenatal clinic, and 79 from the gynecology emergency unit. A structured questionnaire was administered at baseline. Venous blood was obtained at enrolment to test for total antibodies using ELISA. A nasopharyngeal swab was simultaneously obtained for COVID-19 PCR for all participants. Umbilical cord blood was taken after delivery in those who had positive serology. Socio-demographic variables and clinical presentation of respondents were considered as exposure variables, and this was cross-tabulated with outcome variables in bivariate analysis using chi-square with a level of significance at a P-value less than 0.05. Variables in bivariate analysis of chi-square that have a P-value less than 0.2 were entered into a logistic regression using multivariate logistic models. The study detected active COVID-19 infections among 7.4% (19/258) of the study participants. The study demonstrated a seroprevalence of COVID-19 antibodies in 62.4% (161/258) of the participants at recruitment and showed a strong correlation between working in the healthcare setting and living in an urban environment. Our study also reported 5.3% (8/152) of cord blood antibody positivity among study participants. The concentration of maternal immunoglobulin strongly and positively correlated with cord blood seropositivity. Prevalence estimates are an underestimate of the actual proportion of pregnant women with prior COVID-19 exposure as observed in the study discrepancy of confirmed PCR infection and evidence of previous infection from serology. The study also highlighted a low efficiency of placental transfer of COVID-19 antibodies at birth among those who were seropositive at baseline and showed that maternal antibody levels play an important role in determining the efficiency of placenta transfer of COVID-19 antibodies in pregnancy.

EP08.02: Warm reacting anti‐M antibodies in pregnancy: experience of a tertiary women's hospital in Singapore

EP08.02: Warm reacting anti‐M antibodies in pregnancy: experience of a tertiary women's hospital in Singapore

Monoclonal Antibodies in Pregnancy and Breastfeeding in Patients with Multiple Sclerosis: A Review and an Updated Clinical Guide.

The use of high-efficacy disease-modifying therapies (DMTs) early in the course of multiple sclerosis (MS) has been shown to improve clinical outcomes and is becoming an increasingly popular treatment strategy. As a result, monoclonal antibodies, including natalizumab, alemtuzumab, ocrelizumab, ofatumumab, and ublituximab, are frequently used for the treatment of MS in women of childbearing age. To date, only limited evidence is available on the use of these DMTs in pregnancy. We aim to provide an updated overview of the mechanisms of action, risks of exposure and treatment withdrawal, and pre-conception counseling and management during pregnancy and post-partum of monoclonal antibodies in women with MS. Discussing treatment options and family planning with women of childbearing age is essential before commencing a DMT in order to make the most suitable choice for each individual patient.

Management of a rare red cell antibody in pregnancy

Vel is a clinically significant, high incidence blood group antigen. Alloimmunisation of the rare Vel-negative individual (1:4000) with Vel-positive red cells results in the development of anti-Vel antibodies that are associated with severe haemolytic transfusion reactions on re-exposure to Vel-positive blood, necessitating transfusion with exceedingly limited supplies of Vel-negative red cells. We describe a case of patient blood management in a 35-year-old pregnant woman with anti-Vel antibodies and risk for post-partum haemorrhage (PPH). Confirmatory testing for anti-Vel was performed by Lifeblood. There was only one known compatible donor identified in Australia with a very limited inventory of cryopreserved red cells. As the patient was pregnant, autologous collection was not possible. Due to these limitations in supply of Vel-negative red cells, a multifaceted alternative care plan was developed, including: (1) Patient optimisation for delivery, including replacement of haematinic factors; (2) Early anaesthetic and obstetrics involvement was sought in planning delivery; (3) In the event of PPH, a clearly documented prescription of haemostatic products was suggested including upfront cryoprecipitate, platelets, FFP, tranexamic acid, and recombinant Factor VIIa. Fortunately, the patient had an uncomplicated delivery. This case demonstrates the importance of a comprehensive transfusion plan for patients with rare blood groups.

Transplacental transfer of SARS-CoV-2 antibodies: a cohort study

The purpose of this study was to examine the transfer rate of SARS-CoV-2 IgG antibodies in pregnancy and newborns. Two Danish labor wards screened all women for SARS-CoV-2 by PCR upon arrival. Women (n = 99) with a SARS-CoV-2 PCR–positive nasopharyngeal (NP) swab or with a household member with a positive swab at labor or any time during pregnancy, or COVID-19 symptoms upon admission (November 2020 through August 2021), were included. Mother and infant were tested by NP swabs at delivery, and maternal and infant (umbilical cord) venous blood samples were collected. We obtained clinical information including previous PCR test results from the medical records. SARS-Cov-2 IgM and quantified IgG antibodies were measured by enzyme-linked immunosorbent assay and transfer ratios of IgG. We detected IgG antibodies in 73 women and 65 cord blood sera and found a strong correlation between SARS-CoV-2 IgG concentrations in maternal and umbilical cord sera (r = 0.9; p < 0.05). Transfer ratio was > 1.0 in 51 out of 73 (69%) infants and > 1.5 in 26 (35%). We found that transfer was proportional to time from a positive SARS-CoV-2 PCR NP swab to delivery (r = 0.5; p < 0.05). Transfer ratios of SARS-CoV-2 antibodies were associated with time from infection to delivery with transfer ratios of more than 1.0 in the majority of seropositive mother-infant dyads.

Antiphospholipid Antibodies in Pregnancy: Maternal and Neonatal Implications.

Antiphospholipid antibodies (aPL Abs) have long been associated with the occurrence of certain specific pregnancy morbidities, affecting both mother and fetus. Antithrombotic-based prophylactic regimens are the standard of care. Their intensity is modulated by the thrombotic history and has greatly improved the prognosis related to spontaneous morbidity. Observational studies show that this treatment is still associated with the persistence of excess of late-pregnancy placental diseases, calling for new or complementary developments, yet to be validated. Rigorous prospective multicentric validation of clinical and laboratory parameters capable of identifying those women and fetuses at a risk of pejorative evolution, thus early prognosis, is a priority issue. These will make it possible to develop customized treatments and test them. Furthermore, there are still concerns, particularly neurodevelopmental ones, about children born to aPL Ab-positive mothers, and clarification based on regular, more systematic evaluations is required. Even after pregnancy, women with a pure obstetrical antiphospholipid syndrome are at a greater risk of venous and arterial thrombosis over time, and prevention needs to be improved. These women also appear to develop more psychiatric and mood disorders. Central nervous system imaging using high-resolution techniques has shown subtle impairments in the white matter, associated with the most pathogenic aPL Abs and the clinical significance of this is under investigation. These mothers also seem to develop an excess of cancers. The systemic impact of aPL Abs is gradually being suspected, although this requires further evidence, and prevention should be envisaged.

Fetal cardiac fibroelastosis - a consequence of anti-Ro maternal transfer during pregnancy. Case report and review of the literature

With scarcely any reports published on the association of fetal endocardial fibroelastosis and Ro antibodies maternal transfer during pregnancy, this subject continues to raise concern among health care providers around the world, especially when neonatal lupus syndrome is taken into consideration as the main diagnosis. Fetuses with congenital atrioventricular block have a risk of intrauterine fetal demise and the concern comes from a variety of factors that show significant association between the presence of maternal antibodies to SS-A/Ro during pregnancy and their children serum level of these antibodies. Nevertheless, fetal endocardial fibroelastosis plays an important role in altering ventricular diastolic function and ventricular development in children and neonates. Methods. Medical literature was searched on PubMed and Medline using key words such as fetal endocardial fibroelastosis, anti-Ro antibodies in pregnancy and neonatal lupus syndrome and over 200 articles were taken into consideration, with 17 of them included in the final review. The clinical case included in this paper was referred to the Department of Maternal Fetal Medicine, Filantropia Clinical Hospital in Bucharest, during the second pregnancy after a first pregnancy that resulted in stillbirth with congenital heart block and fibroelastosis as a result of the maternal diagnosis of Sjogren’s syndrome with transplacental transfer of SS-A/Ro antibodies.

I Got It from My Mamma: Sensitization by Transplacental Transfer of Maternal HLA Antibodies Managed with Manual Exchange Transfusion

<h3>Introduction</h3> During pregnancy antibodies are passed from mother to fetus with many known immunologic benefits. There is no data about the implications of this on pediatric transplant immunology. We report a case of transplacental transfer of maternal Human Leukocyte Antigen (HLA) antibodies affecting cardiac transplant candidacy in an infant with cardiomyopathy. <h3>Case Report</h3> A 3-week-old Amish boy with a homozygous MYBPC3 mutation causing severe cardiomyopathy admitted for refractory heart failure symptoms was referred for heart transplant evaluation. Labs were notable for high levels of high Mean Fluorescence Intensity (MFI) HLA antibodies (Panel of Reactive Antibodies (PRA) Class I: 74%, Class II: 80%) with no known sensitizing events. Maternal history was remarkable for multiple miscarriages raising the question that his HLA antibodies could be a result of maternal HLA sensitization with transplacental antibody transfer versus active antibody production by the child. Subsequent antibody testing of his mother's blood and breast milk revealed nearly identical HLA antibody profiles to that of the patient. Given the patient's prohibitively small size for antibody removal by plasmapheresis, we elected to perform double volume whole blood exchange transfusions with serial monitoring of his HLA antibodies. Considering his severe ventricular dysfunction, exchange transfusions were performed manually via the push pull method over 6 hours. He ultimately underwent 6 exchange transfusions over the course of 7 weeks. Serial antibody testing revealed a progressive decline in all his HLA antibody levels to <3,000 MFI with only mild rebound after each transfusion consistent with tissue redistribution rather than active antibody production. He was successfully transplanted with a negative PRA (Class I: 0%, Class II: 0%) without post-transplant complications. <h3>Summary</h3> We believe this is the first report demonstrating transplacental acquisition of maternal HLA antibodies in an infant successfully removed via serial whole blood exchange transfusions enabling successful cardiac transplantation.

Subclinical Hypothyroidism with Negative for Thyroid Peroxidase Antibodies in Pregnancy: Intellectual Development of Offspring.

Background: The adverse impact of maternal negative TPOAb of gestational subclinical hypothyroidism (SCH-TPOAb-) on the development of the offspring has not yet been clearly identified. A lingering controversy exists over the treatment of SCH-TPOAb- diagnosed during pregnancy. Therefore, this study was designed to evaluate the intellectual development of children of mothers who had SCH-TPOAb-. Methods: A number of 139 children were recruited; 112 children were born to SCH TPOAb- and 27 children were born to euthyroid TPOAb- mothers. Based on the mothers' thyrotropin (TSH) levels during pregnancy and whether or not they received levothyroxine (LT4) treatment, the children were assigned to four groups: Group A (2.5 mIU/L < TSH ≤4.0 mIU/L, n = 31) and Group B (4.0 mIU/L < TSH ≤10.0 mIU/L, n = 26), whose mothers were treated with LT4 before eight gestational weeks, and Group C (2.5 mIU/L < TSH ≤4.0 mIU/L, n = 27) and Group D (4.0 mIU/L < TSH ≤10.0 mIU/L, n = 28), whose mothers received no treatment. A total number of 27 children whose mother's serum TSH was <2.5 mIU/L and were TPOAb- during their pregnancy served as the control group (Group E). The intellectual development of two-year-old children was assessed and compared using the Gesell Development Diagnosis Scale. Results: The developmental quotient (DQ) in Group D was 8.67 lower than this in Group E (p < 0.001). More specifically, gross motor quotient, fine motor quotient, adaptability quotient (ABQ), language quotient (LQ), and individual social behavior quotient (ISBQ) of DQ in Group D were significantly lower than those in Group E. No significant differences were observed in DQ among Group A, Group B, Group C, and Group E (p > 0.05). Spearman's rank correlation analysis showed that DQ, FMQ, ABQ, LQ, and ISBQ were significantly negatively correlated with the TSH level (r = -0.417, -0.253, -0.273, -0.436, and -0.272; p < 0.05). In addition, multivariate logistic regression analysis revealed that mothers' education (short education), mothers' education (medium education), and TSH level (4.0 mIU/L < TSH ≤10.0 mIU/L) were both risk factors affecting the intellectual development of the offspring (p < 0.05). Conclusion: The effects of the intellectual development of the offspring with SCH-TPOAb- are related to the level of TSH. Standardized treatment for SCH-TPOAb- pregnant women before eight gestational weeks, whose TSH level was from 4.0 to 10.0 mIU/L, may significantly improve the intellectual development levels of the approximately two-year-old offspring. Although our study was a historical cohort study, the data analyzed provide the foundation for further investigation. Further prospective intervention trials with large numbers of participants are needed to confirm our conclusions. The Clinical Trial Registration number is 2021-K-84-02.

Hemolysis in Early Infancy: Still a Cause of Cholestatic Neonatal Giant Cell Hepatitis.

Before the prophylactic use of anti-D antibodies in pregnancy, hemolytic anemia of the newborn was the most common cause of hyperbilirubinemia. Nowadays, given the rarity of hemolytic anemia of the newborn, hepatobiliary abnormalities, perinatal infections, and metabolic disorders have become the most common conditions in the differential diagnosis of neonatal cholestasis. Here, we report 3 instances of cholestatic giant cell hepatitis in 3 infants who had Coombs' positive hemolysis due to ABO incompatibility in 1, Rh incompatibility in another, and combined ABO and Rh incompatibility in the third. Although rare, cholestatic neonatal giant cell hepatitis associated with hemolysis still needs to be considered in patients with neonatal cholestasis. A marked elevation of aspartate aminotransferase over alanine aminotransferase can be a helpful clue to an early diagnosis.

Seroprevalence, Associated Factors, and Fetomaternal Outcome in Pregnant Women That Tested Positive to Hepatitis E Antibodies in Nigeria.

Background Hepatitis E virus infection is an emerging disease with varied courses in pregnancy. There is a dearth of statistics among pregnant women. Aim To evaluate the prevalence, associated factors, and pregnancy outcome in women that tested positive for hepatitis E virus (HEV) antibodies in pregnancy. Research Methods. This was a cross-sectional study conducted among pregnant women at a teaching hospital in Nigeria. Relevant information was collected using a structured questionnaire. Blood was collected from each of the participants, and the serum was used to determine the presence of hepatitis E immunoglobulin M (IgM) and G (IgG). The data were analysed using SPSS version 23. Associations between variables were determined at a p value of <0.05. Results A total of 200 pregnant women participated in this study. The prevalence of HEV infection among pregnant women was 28.00% (56/200). The mean age was 30.11 ± 5.88. Hepatitis E infection was significantly associated with age (p value = 0.028), method of faecal disposal (p value = 0.043), and source of drinking water (p value = 0.039). A total of 9/200 (4.50%) stillbirths were recorded with 3/9 (33.33%) in women that tested positive for HEV antibodies. About 4/200(2.00%) miscarriages were recorded, and 2/4 (50.00%) were in women that tested positive for HEV antibodies. Hepatitis E infection was not significantly associated with perinatal outcome (p value = 0.45). Only 1/56 (0.50%) maternal death was recorded among women that tested positive to hepatitis E, and none was recorded among those that tested negative to hepatitis E antibodies. Conclusion There was a significant statistical association between HEV infection and age, method of faecal disposal, and source of drinking water. This underscores the importance of the provision of clean water and safe faecal disposal. Hepatitis E virus infection did not significantly affect the foetal and maternal outcomes.

VP32.05: The prevalence of maternal cytomegalovirus antibody in pregnancy

VP32.05: The prevalence of maternal cytomegalovirus antibody in pregnancy

Management and clinical consequences of red blood cell antibodies in pregnancy: A population-based cohort study.

Anti-D alloimmunization is the most common cause of severe hemolytic disease of the fetus and newborn (HDFN). The management of pregnancies affected by less frequent red blood cell (RBC) antibodies poses a challenge to clinicians, and perinatal outcomes are less well described. This study aimed to describe the frequency of clinically significant RBC antibodies in our pregnant population and analyze the risk of prenatal and postnatal treatment for HDFN in relation to our national risk classification system and management guidelines. A retrospective cohort study in the population of all alloimmunized singleton pregnancies in the Stockholm region 1990-2016. Descriptive summaries of different RBC antibodies and pregnancy outcomes were presented, the risks of intrauterine blood transfusion (IUT) and neonatal treatment for HDFN were estimated by type of antibodies. Of the 1724 alloimmunized pregnancies, 1079 (63%) were at risk of HDFN and constituted our study cohort. Anti-D was detected in 492 (46%) pregnancies, followed by anti-E in 161 (15%), and anti-c in 128 (12%). Eighty-seven (8%) pregnancies had IUT, with the highest risk in pregnancies affected by anti-D combined with other antibodies. The maximum titer recorded before IUT was 64 or above, except for two pregnancies affected by anti-c, for which the maximum titers were 8 and 16. For the 942 (95%) live-born neonates from 992 alloimmunized pregnancies without IUT, the median gestational age at birth was 38+5 weeks compared with 35+5 weeks for those who had IUT. Neonatal treatment was most common in the anti-D alone and anti-D combined groups, with 136 (57%) and 21 (44%), respectively, treated with phototherapy and 35 (15%) and 9 (20%) receiving exchange transfusions, respectively. For pregnancies complicated by moderate- and low-risk antibodies, phototherapy was less frequent (32 [36%] and 21 [19%]) and exchange transfusion was rare (5 [6%] and 3 [3%]). Anti-D, especially in combination with other antibodies, presents the highest risk of severe HDFN. The classification of less frequent and less well-known RBC antibodies into risk groups can help clinicians in assessing the risk of HDFN and counseling alloimmunized pregnant women regarding the risk of prenatal and postnatal treatments.

Safety profile of anti-calcitonin gene-related peptide monoclonal antibodies in pregnancy, lactation and fertility: analysis of the WHO global pharmacovigilance database

Safety profile of anti-calcitonin gene-related peptide monoclonal antibodies in pregnancy, lactation and fertility: analysis of the WHO global pharmacovigilance database