Intrauterine enzyme replacement therapies for lysosomal storage disorders: Current developments and promising future prospects.

Lysosomal storage disorders (LSDs) are a group of monogenic condition, with many characterized by an enzyme deficiency leading to the accumulation of an undegraded substrate within the lysosomes. For those LSDs, postnatal enzyme replacement therapy (ERT) represents the standard of care, but this treatment has limitations when administered only postnatally because, at that point, prenatal disease sequelae may be irreversible. Furthermore, most forms of ERT, specifically those administered systemically, are currently unable to access certain tissues, such as the central nervous system (CNS), and furthermore, may initiate an immune response. In utero enzyme replacement therapy (IUERT) is a novel approach to address these challenges evaluated in a first-in-human clinical trial for IUERT in LSDs (NCT04532047). IUERT has numerous advantages: in-utero intervention may prevent early pathology; the CNS can be accessed before the blood-brain barrier forms; and the unique fetal immune system enables exposure to new proteins with the potential to prevent an immune response and may induce sustained tolerance. However, there are challenges and limitations for any fetal procedure that involves two patients. This article reviews the current state of IUERT for LSDs, including its advantages, limitations, and potential future directions for definitive therapies.

How do we perform intrauterine transfusions?

BACKGROUND: Intrauterine transfusion (IUT) is an invasive but critical and potentially life-saving intervention for severe fetal anemia with demonstrated improvement in outcomes. The fetus is vulnerable to hemodynamic alterations and transfusion-related adverse events; therefore, special consideration must be given to blood component selection and modification. There is widespread IUT practice variability, and existing guidance primarily relies on expert opinion and single center experiences. STUDY DESIGN AND METHODS: Experts in Maternal Fetal Medicine, Pediatric Hematology, and Transfusion Medicine from centers across the United States, collectively performing about 120 IUT annually, offer a multidisciplinary perspective on the performance of IUT and preparation of blood components. This perspective includes strategies for identifying an at-risk fetus, communicating between disciplines, determining the necessary blood volume, selecting and processing blood components, documenting the procedure in medical record, and managing the neonate. RESULTS: Identifying an at-risk fetus relies on review of the clinical history, non-invasive monitoring, and laboratory evaluation. We recommend the use of relatively fresh, group O, cytomegalovirus-safe, freshly irradiated, red blood cells (RBC) that are Hemoglobin S negative and antigen-negative for any maternal antibody, if indicated. These RBC units should be concentrated to remove additives and increase the hematocrit thus minimizing fluctuations in fetal volume status. The units intended for IUT should be labeled clearly and the documentation of transfusion differentiated in the maternal medical record. DISCUSSION: An awareness of the technical, logistical, and regulatory considerations for IUT performance will facilitate improved communication and patient care, especially when rare units of RBC are required.

Understanding Preterm Birth in Pregnancies Complicated by Nonimmune Hydrops Fetalis.

OBJECTIVE: Nonimmune hydrops fetalis (NIHF) is associated with poor perinatal outcomes including preterm birth (PTB). However, the frequency and causes of PTB in this population are not well understood. We hypothesized that NIHF frequently results in PTB due to medically indicated delivery for fetal distress. STUDY DESIGN: This was a secondary analysis of a prospectively enrolled cohort of pregnancies with NIHF that underwent exome sequencing if standard testing was nondiagnostic. The primary outcome was frequency of PTB at <37 weeks' gestation. Secondary outcomes were reasons for PTB, fetal predictors of PTB, and frequency of neonatal death following PTB. RESULTS: Fifty-six cases were included, with a median gestational age at delivery of 32.8 weeks (interquartile range [IQR]: 30.3-35.0). Overall, 86% (48/56) were delivered preterm. Among 48 PTBs, 18 (38%) were spontaneous, 9 (19%) were medically indicated for maternal indications (primarily preeclampsia), and 21 (44%) were medically indicated for fetal indications (nonreassuring antenatal testing or worsening effusions). Neither fetal genetic diagnosis nor polyhydramnios was associated with PTB. CONCLUSION: More than four-fifths of pregnancies with NIHF result in PTB, often due to nonreassuring fetal status. These data are informative for counseling patients and for developing strategies to reduce PTB in pregnancies with NIHF. KEY POINTS: · Pregnancies complicated by nonimmune hydrops fetalis often result in preterm birth.. · Preterm birth in these cases is most often medically indicated for fetal benefit.. · Fetal genetic conditions and polyhydramnios may be associated with preterm birth in cases of NIHF..

The impact of in utero transfusions on perinatal outcomes in patients with alpha thalassemia major: the UCSF registry.

Alpha thalassemia major (ATM) is a hemoglobinopathy that usually results in perinatal demise if in utero transfusions (IUTs) are not performed. We established an international registry (NCT04872179) to evaluate the impact of IUTs on survival to discharge (primary outcome) as well as perinatal and neurodevelopmental secondary outcomes. Forty-nine patients were diagnosed prenatally, 11 were diagnosed postnatally, and all 11 spontaneous survivor genotypes had preserved embryonic zeta-globin levels. We compared 3 groups of patients; group 1, prenatally diagnosed and alive at hospital discharge (n = 14), group 2, prenatally diagnosed and deceased perinatally (n = 5), and group 3, postnatally diagnosed and alive at hospital discharge (n = 11). Group 1 had better outcomes than groups 2 and 3 in terms of the resolution of hydrops, delivery closer to term, shorter hospitalizations, and more frequent average or greater neurodevelopmental outcomes. Earlier IUT initiation was correlated with higher neurodevelopmental (Vineland-3) scores (r = -0.72, P = .02). Preterm delivery after IUT was seen in 3/16 (19%) patients who continued their pregnancy. When we combined our data with those from 2 published series, patients who received ≥2 IUTs had better outcomes than those with 0 to 1 IUT, including resolution of hydrops, delivery at ≥34 weeks gestation, and 5-minute appearance, pulse, grimace, activity, and respiration scores ≥7. Neurodevelopmental assessments were normal in 17/18 of the ≥2 IUT vs 5/13 of the 0 to 1 IUT group (OR 2.74; P = .01). Thus, fetal transfusions enable the survival of patients with ATM and normal neurodevelopment, even in those patients presenting with hydrops. Nondirective prenatal counseling for expectant parents should include the option of IUTs.

Survey of intrauterine red blood cell (RBC) transfusion practices in the United States.

BACKGROUND: A paucity of data exists about the current practice of fetal red blood cell (RBC) transfusion in the United States (US). This investigation describes intrauterine transfusion (IUT) RBC product selection and processing practices at different US institutions. METHODS: A transfusion medicine and maternal-fetal medicine (MFM) team designed a survey to interrogate and characterize RBCs utilized for IUT. This survey was distributed to seventy US institutions with fetal treatment centers (October 2020-April 2021) identified through the NAFTNet (North American Fetal Therapy Network). RESULTS: Thirty-seven institutions responded (response rate 53%, 37/70), but five were excluded for not performing IUTs. Most (84%; 27/32) performed 1-24 IUTs annually; two performed >50 IUTs/year. Group O, Rh(D) negative RBC units were always used by 66% (21/32), and 75% (24/32) provided hemoconcentrated RBCs by washing (17/24) or dry packing (6/24). Overall, 66% (21/32) targeted a hematocrit ≥75%. Fifty percent provided both leukocyte-reduced and CMV-negative RBC units. Irradiation of RBC units was performed within 6 h of issue at 63% (20/32) of sites. Most (81%, 26/32) used RBC units at <7 days of age after collection, 56% (18/32) always provided washed RBC units, while 19% (6/32) issued washed RBC only if fresh units are unavailable. Implicated maternal RBC alloantibodies were matched for 78% (25/32) of the time. The transfused volume was universally determined by the MFMs. DISCUSSION: Heterogeneity and lack of standardization exist in RBC product selection and special processing steps for IUTs in the US. Hence, the establishment of a consensus to standardize IUT protocols is needed.

Prenatal Somatic Cell Gene Therapies: Charting a Path Toward Clinical Applications (Proceedings of the CERSI-FDA Meeting).

We are living in a golden age of medicine in which the availability of prenatal diagnosis, fetal therapy, and gene therapy/editing make it theoretically possible to repair almost any defect in the genetic code. Furthermore, the ability to diagnose genetic disorders before birth and the presence of established surgical techniques enable these therapies to be delivered safely to the fetus. Prenatal therapies are generally used in the second or early third trimester for severe, life-threatening disorders for which there is a clear rationale for intervening before birth. While there has been promising work for prenatal gene therapy in preclinical models, the path to a clinical prenatal gene therapy approach is complex. We recently held a conference with the University of California, San Francisco-Stanford Center of Excellence in Regulatory Science and Innovation, researchers, patient advocates, regulatory (members of the Food and Drug Administration), and other stakeholders to review the scientific background and rationale for prenatal somatic cell gene therapy for severe monogenic diseases and initiate a dialogue toward a safe regulatory path for phase 1 clinical trials. This review represents a summary of the considerations and discussions from these conversations.

Perinatal outcomes and 2017 ACC/AHA blood pressure categories.

OBJECTIVE: To evaluate the association of blood pressure category < 20 weeks according to the 2017 American College of Cardiology/American Heart Association (ACC/AHA) criteria with adverse perinatal outcomes. STUDY DESIGN: A retrospective cohort study of singleton deliveries between 1/2014 and 10/2017 was undertaken. Blood pressure category assigned by 2017 ACC/AHA criteria applied to blood pressures prior to 20 weeks gestation: normal (systolic < 120 and diastolic < 80), elevated blood pressure (systolic 120-129 and diastolic < 80 mmHg), stage 1 hypertension (systolic 130-139 and/or diastolic 80-89), stage 2 hypertension (prior diagnosis of chronic hypertension or systolic ≥ 140 or diastolic ≥ 90 mmHg). MAIN OUTCOME MEASURES: The primary outcome was preeclampsia. Secondary outcomes included preterm birth and postpartum readmission. Chi-square, ANOVA and Kruskal-Wallis tests and multivariable Poisson regression were used for analysis. RESULTS: Of the 6,067 eligible pregnancies, 3,855 (63.5%) had normotensive blood pressure, 1,224 (20.2%) elevated blood pressure, 624 (10.3%) stage 1 hypertension, and 364 (6.0%) stage 2 hypertension. Compared to 4.6% prevalence of preeclampsia among normotensive pregnancies, higher categories were associated with higher preeclampsia prevalence: elevated blood pressure (10.7%, adjusted relative risk (aRR) 2.2, 95% confidence interval (CI) 1.8-2.6), stage 1 hypertension (15.1%, aRR 2.7, 95% CI 2.2-3.4) and stage 2 hypertension (38.7%, aRR 6.2, 95% CI 5.1-7.4). Non-normal categories were also associated with a higher risk of preterm birth and postpartum readmission. CONCLUSION: Patients with elevated blood pressure and stage 1 and 2 hypertension at < 20 weeks are at increased risk of adverse obstetric perinatal outcomes.

Use of Ballistocardiography to Monitor Cardiovascular Hemodynamics in Preeclampsia.

Objective: Pregnancy requires a complex physiological adaptation of the maternal cardiovascular system, which is disrupted in women with pregnancies complicated by preeclampsia, putting them at higher risk of future cardiovascular events. The measurement of body movements in response to cardiac ejection via ballistocardiogram (BCG) can be used to assess cardiovascular hemodynamics noninvasively in women with preeclampsia. Methods: Using a previously validated, modified weighing scale for assessment of cardiovascular hemodynamics through measurement of BCG and electrocardiogram (ECG) signals, we collected serial measurements throughout pregnancy and postpartum and analyzed data in 30 women with preeclampsia and 23 normotensive controls. Using BCG and ECG signals, we extracted measures of cardiac output, J-wave amplitude × heart rate (J-amp × HR). Mixed-effect models with repeated measures were used to compare J-amp × HRs between groups at different time points in pregnancy and postpartum. Results: In normotensive controls, the J-amp × HR was significantly lower early postpartum (E-PP) compared with the second trimester (T2; p = 0.016) and third trimester (T3; p = 0.001). Women with preeclampsia had a significantly lower J-amp × HR compared with normotensive controls during the first trimester (T1; p = 0.026). In the preeclampsia group, there was a trend toward an increase in J-amp × HR from T1 to T2 and then a drop in J-amp × HR at T3 and further drop at E-PP. Conclusions: We observe cardiac hemodynamic changes consistent with those reported using well-validated tools. In pregnancies complicated by preeclampsia, the maximal force of contraction is lower, suggesting lower cardiac output and a trend in hemodynamics consistent with the hyperdynamic disease model of preeclampsia.

Racial/ethnic disparities among women receiving intrauterine transfusions for alloimmunization at a single fetal treatment center.

Disparities are prevalent in numerous areas of healthcare. We sought to investigate whether there were racial/ethnic disparities among pregnant women with the most severe form of alloimmunization who require intrauterine transfusions (IUT). We reviewed patients who underwent IUT for alloimmunization at a single fetal treatment center between 2015 and 2020. This "IUT cohort" was compared to an "Alloimmunization cohort": patients seen at our institution with a diagnosis of alloimmunization during pregnancy, who did not receive IUT. We collected maternal demographics including self-identified race/ethnicity and primary language, transfusion, and antibody characteristics. The cohorts were compared using unpaired t-tests, Mann-Whitney tests, and Fischer's exact tests, as appropriate. The IUT cohort included 43 patients and the alloimmunization cohort included 1049 patients. Compared to the alloimmunization cohort, there were significantly more patients of Latina descent in the IUT cohort (23.3% vs. 3.4%, p < .0001), and more non-English speakers (18.6% vs. 4.6%, p = .001). Twenty-one percent (9/43) of patients had immigrated to the United States, all of whom had pregnancies or miscarriages in their country of origin. A third of patients had new antibodies identified on serial screens during the current pregnancy. Significantly more women of Latina ethnicity and non-English speakers required IUTs compared to the cohort of women with alloimmunization. Insufficient access to care prior to arriving in the United States and among racial and ethnic minorities in the United States may contribute to these findings. Providers should be cognizant of potential, racial, and ethnic inequalities among women receiving intrauterine transfusions.

Fetal Congenital Pulmonary Airway Malformation: The Role of an Objective Measurement of Cardiomediastinal Shift.

OBJECTIVE: To examine the relationship between cardiomediastinal shift angle (CMSA) and adverse perinatal outcomes and hydrops in cases of congenital pulmonary airway malformation (CPAM). STUDY DESIGN: This retrospective study evaluated CPAM cases referred to our institution from 2008 to 2015. The primary outcome was a composite score for adverse perinatal outcome. CMSA was measured for each case and evaluated for its association with the primary outcome. The prediction accuracy of CMSA for adverse perinatal outcome was assessed using receiver operator characteristic (ROC) curves. RESULTS: Eighteen (21.2%) of the 85 cases experienced an adverse perinatal outcome. Increases in CMSA were associated with adverse perinatal outcomes and hydrops in bivariate analyses. Adjusted analyses found each 10-degree increase in CMSA to be associated with increased odds of an adverse perinatal outcome (adjusted odds ratio [aOR] 2.2, 95% confidence interval [CI]: 1.4-3.3) and hydrops (aOR 3.0, 95% CI: 1.5-6.1). CMSA performed well and was comparable to CPAM volume ratio in predicting adverse perinatal outcomes (area under the curve 0.81 and 0.84, respectively). CONCLUSION: We describe a novel measurement of mediastinal shift in cases of CPAM and its relationship with adverse perinatal outcomes and hydrops. These findings may shape the evaluation and management of CPAMs, improve our understanding of their prognosis, and influence patient counseling.

Gender Differences in Academic Rank and NIH Funding among Academic Maternal-Fetal Medicine Physicians in the United States.

OBJECTIVE: This article evaluates gender differences in academic rank and National Institutes of Health (NIH) funding among academic maternal-fetal medicine (MFM) physicians. STUDY DESIGN: This was a cross-sectional study of board-certified academic MFM physicians. Physicians were identified in July 2017 from the MFM fellowship Web sites. Academic rank and receipt of any NIH funding were compared by gender. Data on potential confounders were collected, including years since board certification, region of practice, additional degrees, number of publications, and h-index. RESULTS: We identified 659 MFM physicians at 72 institutions, 312 (47.3%) male and 347 (52.7%) female. There were 246 (37.3%) full, 163 (24.7%) associate, and 250 (37.9%) assistant professors. Among the 154 (23.4%) MFM physicians with NIH funding, 89 (57.8%) were male and 65 (42.2%) were female (p = 0.003). Adjusting for potential confounders, male MFM physicians were twice as likely to hold a higher academic rank than female MFM physicians (adjusted odds ratio [aOR], 2.04 [95% confidence interval, 1.39-2.94], p < 0.001). There was no difference in NIH funding between male and female MFM physicians (aOR, 1.23 [0.79-1.92], p = 0.36). CONCLUSION: Compared with female academic MFM physicians, male academic MFM physicians were twice as likely to hold a higher academic rank but were no more likely to receive NIH funding.

Solid pseudopapillary neoplasm of the pancreas head in a pregnant woman: safe pancreaticoduodenectomy postpartum.

Solid pseudopapillary neoplasms (SPNs) of the pancreas are rare and typically arise in young women. The optimal management of a pregnant woman suspected of having an SPN of the pancreas head is unclear. We report such a case where close monitoring for tumor growth was done during pregnancy and a successful pancreaticoduodenectomy was performed after term delivery.