Managing Monoamniotic Twin Pregnancies.

Monoamniotic twins comprise a rare subset of twins at risk of unique and serious complications. In addition to the risks faced by all twins (premature birth, growth restriction), all monochorionic twins (twin-to-twin transfusion syndrome), and all monozygotic twins (congenital anomalies), monoamniotic twins face the unique risk of cord entanglement, in addition to a markedly increased risk of congenital anomalies. Early diagnosis, screening for fetal anomalies and surveillance for twin-twin transfusion syndrome are critical. After fetal viability, frequent fetal monitoring reduces the risk of intrauterine fetal demise.

The radiologist's role in a multidisciplinary approach to cancer in pregnancy.

Pregnancy-associated cancer (PAC) occurs in approximately 1 in 1000 pregnancies, and the incidence is expected to rise due to delayed childbearing (Silverstein et al. in JCO Oncol Pract 16:545-557, 2020; Woitek et al. in ESMO Open 1:e000017, 2016). Diagnosis and management of PACs are challenging and diagnosis is often delayed as symptoms may overlap with physiologic changes of pregnancy (Jha et al. in RadioGraphics 42:220005, 2022). These patients are best cared for by a multidisciplinary healthcare team composed of experts (Silverstein et al. in JCO Oncol Pract 16:545-557, 2020). Management of these patients must balance optimal maternal care with potentially harmful fetal effects. This involves honest, forthright, and sometimes difficult discussions between the care team and the patient throughout the entirety of care. Radiologists play a significant role in timely cancer diagnosis, staging and follow-up during and after pregnancy, accurate determination of gestational age, and in assessing fetal growth and well-being throughout pregnancy.

Multidisciplinary Management of Cancer During Pregnancy.

Cancer during pregnancy is relatively rare but is increasing in frequency in countries in which the maternal child-bearing age continues to rise. The complexities of medical decision making are underscored by the need to weigh the potential benefits of any intervention for the mother against the risks to the fetus. A majority of diagnostic evaluations can be performed safely in the setting of pregnancy and should not be delayed. Noninvasive prenatal testing that shows discordance with fetal karyotype can be a clue to an underlying maternal malignancy. After diagnosis, a multidisciplinary team should formulate a care plan for both the mother and the fetus. Key topics for discussion should include the mother's prognosis, standard treatment plan, and predictions of how modifications for a continuing pregnancy will affect the treatment plan and overall prognosis. In the context of this knowledge, frank discussions about pregnancy termination should be addressed with the patient, if appropriate. Selection of a plan for oncologic management in the case of a pregnant woman is based on the type of cancer, the tumor biology, and the tumor stage. Additional complexities for pregnant patients are typically related to the gestational age of the fetus, the dynamic physiologic changes of pregnancy, and the limited safety data for administration of most anticancer therapies during pregnancy. In this article, we summarize data related to different classes of anticancer therapies as well as considerations for the management of selected cancers. Finally, we provide some key principles that should be considered in the management of patients with cancer during pregnancy.

Efficiency of placental transfer of vaccine-elicited antibodies relative to prenatal Tdap vaccination status.

Administration of vaccines during pregnancy provides maternal protection against infectious diseases. This protection is extended to their infants during the first months of life, as pathogen-specific antibodies formed in response to maternal vaccination are transferred across the placenta to the fetus. Notably, Tdap (tetanus-diphtheria-acellular pertussis) vaccination booster is routinely administered to pregnant women both to prevent neonatal tetanus and to ensure that infants have protective levels of pertussis antibodies until they are able to establish their own vaccine-induced levels. Whether infant protection through maternal immunization is merely due to an increase in maternal antibody levels or whether maternal immunization enhances the transfer of vaccine-specific antibodies is unclear. Moreover, the potential impact of prenatal vaccinations on the transplacental transfer of other antibodies, such as antibodies raised as a result of infections or other vaccines administered prior to pregnancy, has not been studied. The goal of this study was to define the impact of maternal vaccination on IgG transplacental transfer efficiency. We analyzed antigen-specific antibody populations and IgG subclass distribution in maternal and cord blood samples from 58 mother-infant pairs. All women received the seasonal inactivated influenza vaccine during pregnancy and 25 women received the Tdap vaccine during the second or third trimester of gestation. Prenatal Tdap vaccination did not impact the efficiency of IgG transplacental transfer; however, it was associated with higher maternal and infant vaccine-elicited Tdap-specific antibody levels, and with a higher proportion of infants with protective levels of antibodies, especially against diphtheria. There was also no difference in the IgG transplacental transfer rate of antibodies against non-Tdap vaccines between the two groups of women. Our results confirm previous reports demonstrating the benefits of prenatal Tdap immunization and indicate that this strategy does not impede the transplacental transfer of other antibodies that are also important for infant protection.

Assessing patient perceptions of cytomegalovirus infection in pregnancy.

Pregnant women impacted by cytomegalovirus (CMV) make clinical decisions despite uncertain outcomes. Intolerance of uncertainty score (IUS) is a validated measure of tendency for individuals to find unacceptable that a negative event might occur. We investigated patient perceptions of CMV infection during pregnancy and correlated IUS and knowledge with decision-making. Electronic questionnaire was sent to women from July to August 2017. The questionnaire evaluated knowledge of CMV, IUS, and responses regarding management to three clinical scenarios with escalating risk of CMV including choices for no further testing, ultrasound, amniocentesis, or abortion. For each scenario, logistic regression was used to model IUS on responses. A total of 815 women were included. The majority of participants was white (63.1%) and 42% had a postgraduate degree. Over 70% reported that they had not previously heard of CMV. In the scenario with only CMV exposure, participants with increasing IUS were more likely to choose abortion (odds ratio [OR] = 1.04; 95% confidence interval [CI]: 1.01, 1.06) and no further testing (OR = 0.97; 95% CI: 0.95, 0.99). In the scenario with mild ultrasound findings in setting of CMV exposure, increasing IUS was associated with higher odds of choosing no further testing (OR = 0.97; 95% CI, 0.94, 0.99). No significant association was observed between IUS and responses in the scenario with severe ultrasound abnormalities in setting of CMV exposure. The majority of patients had no knowledge of CMV. Higher IUS was associated more intervention in low severity scenarios, but in severe scenarios, IUS was not associated with participants' choices.

Management Considerations for Recalcitrant Hyperemesis.

IMPORTANCE: Hyperemesis gravidarum (HEG) affects 0.3% to 3% of pregnancies and requires additional therapies beyond those commonly used for less severe instances of nausea and vomiting of pregnancy (NVP). Differentiating between NVP and HEG is a vital yet challenging function for any obstetrician. The literature for management of HEG is lacking compared with that of NVP. OBJECTIVE: Review etiology of NVP/HEG highlights key considerations in the workup of HEG as they compare to NVP and explore management options for recalcitrant HEG focusing principally on how they affect maternal and fetal outcomes and secondarily on where data are nonprescriptive. EVIDENCE ACQUISITION: This was a literature review primarily using PubMed and Google Scholar. RESULTS: Short-course corticosteroids and treatment for Helicobacter pylori have the most favorable risk-reward profiles of the 4 pharmacologic therapies evaluated. Mirtazapine and diazepam may have a place in highly selected patients. If nutritional supplementation is required, enteral nutrition is strictly preferred to parenteral nutrition. Postpyloric feeding approaches are less likely to induce vomiting. Surgically placed feeding tubes are less likely to be dislodged and may be worth the invasive insertion procedure if nasogastric or nasojejunal tubes are not tolerated. CONCLUSIONS AND RELEVANCE: Hyperemesis gravidarum is a diagnosis reserved for refractory cases of NVP and therefore by definition poses treatment challenges. Any clinical presentation that lent itself to prescriptive, algorithmic management would likely fall short of the diagnostic criteria for HEG. However, data can inform management on a patient-by-patient basis or at least help patient and provider understand risks and benefits of therapies reserved for refractory cases.

Neonatal Outcomes Associated with Noncephalic Presentation at Delivery in Preterm Birth.

OBJECTIVE: The objective of this study is to evaluate the effect of noncephalic presentation on neonatal outcomes in preterm delivery. STUDY DESIGN: In this study a secondary analysis of the BEAM trial was performed. It included women with singleton, liveborn, and nonanomalous fetuses. Neonatal outcomes were compared in noncephalic versus cephalic presentation. Adjusted odds ratios and 95% confidence intervals were calculated for each outcome with logistic regression while controlling for possible confounders. A stratified analysis by mode of delivery was also performed in this study. RESULTS: A total of 458 noncephalic deliveries were compared with 1,485 cephalic deliveries. In multivariate analysis, noncephalic presentation was associated with increased risk of death in the neonatal intensive care unit (NICU) or death at <15 months corrected gestational age (cGA), and a decreased risk of IVH. The risk of death persisted in stratified analysis, with increased risk of death at <15 months cGA in noncephalic neonates born via cesarean delivery. In the vaginal delivery group, there was an increased risk of death at <15 months cGA and NICU death. CONCLUSION: After controlling for possible confounders, neonates who are noncephalic at delivery have higher risk for death <15 months cGA and death in the NICU while their risk of IVH is reduced. The risk of death persisted in stratified analyses by mode of delivery.

What's New in Prenatal Genetics? A Review of Current Recommendations and Guidelines.

IMPORTANCE: The rapid development of prenatal genetic testing and screening tools and choices constantly challenges clinicians to stay up to date on current best practice. OBJECTIVE: We sought to review, compare, and summarize recent national society guidelines on prepregnancy genetic screening and prenatal diagnosis for aneuploidy with a focus on changes and additions to previous guidelines. EVIDENCE ACQUISITION: We performed a descriptive review of 8 recently published (2016-2017) national guidelines and updates on prenatal genetic screening and testing including American Congress of Obstetricians and Gynecologists committee opinions and practice bulletins, Society for Maternal-Fetal Medicine consult series publications, and an American College of Medical Genetics and Genomics position statement. Topics included carrier screening, cell-free DNA screening, chromosomal microarray analysis, next-generation sequencing, and prenatal diagnostic testing. The recommendations in these publications were compared, and the additions and changes to previous recommendations and guidelines were summarized. RESULTS: Recent publications contain many updates and changes to previous screening and testing strategies, most of which are consistent between professional societies. Although many new technologies have been integrated into prenatal diagnosis, some newer technologies are not yet routinely recommended for widespread use, often because of lack of clinical trials and validation studies. CONCLUSIONS: Prenatal screening and testing options are rapidly expanding. To provide best-practice prenatal care, obstetric care providers should educate themselves about the most up-to-date recommendations and be prepared to interpret and apply these guidelines to their patients. Society guidelines are largely in agreement.

Characterization of choline transporters in the human placenta over gestation.

INTRODUCTION: The developing fetus relies on the maternal blood supply to provide the choline it requires for making membrane lipids, synthesizing acetylcholine, and performing important methylation reactions. It is vital, therefore, that the placenta is efficient at transporting choline from the maternal to the fetal circulation. Although choline transporters have been found in term placenta samples, little is known about what cell types express specific choline transporters and how expression of the transporters may change over gestation. The objective of this study was to characterize choline transporter expression levels and localization in the human placenta throughout placental development. METHODS: We analyzed CTL1 and -2 expression over gestation in human placental biopsies from 6 to 40 weeks gestation (n = 6-10 per gestational window) by immunoblot analysis. To determine the cellular expression pattern of the choline transporters throughout gestation, immunofluorescence analysis was then performed. RESULTS: Both CTL1 and CTL2 were expressed in the chorionic villi from 6 weeks gestation to term. Labor did not alter expression levels of either transporter. CTL1 localized to the syncytial trophoblasts and the endothelium of the fetal vasculature within the chorionic villous structure. CTL2 localized mainly to the stroma early in gestation and by the second trimester co-localized with CTL1 at the fetal vasculature. DISCUSSION: The differential expression pattern of CTL1 and CTL2 suggests that CTL1 is the key transporter involved in choline transport from maternal circulation and both transporters are likely involved in stromal and endothelial cell choline transport.

Managing Monoamniotic Twin Pregnancies.

Monoamniotic twins comprise a rare but important subset of twins at risk of unique and serious complications, placing them at the highest risk of perinatal mortality of all twin gestations. In addition to risks faced by all twins (prematurity, selective growth restriction), all monochorionic twins (twin-twin transfusion syndrome), and all monozygotic twins (congenital anomalies), monoamniotic twins face the unique risk of cord entanglement. Accordingly, early diagnosis, screening for fetal anomalies, surveillance for twin-twin transfusion syndrome, decisions related to monitoring after viability, and timing and route of delivery are all critical. Herein, we present recommendations for optimal management.

Fetal weight estimation in diabetic pregnancies using the gestation-adjusted projection method: comparison of two timing strategies for third-trimester sonography.

OBJECTIVES: The gestation-adjusted projection method extrapolates birth weight using third-trimester sonography. This technique is shown to be more accurate for sonographic examinations from 34 weeks to 36 weeks 6 days than 37 weeks to 38 weeks 6 days. Our objective was to determine whether even earlier sonographic examinations (31 weeks-33 weeks 6 days) further improves birth weight prediction in patients with diabetes. METHODS: We conducted a retrospective cohort analysis of 388 pregnant women with pregestational or gestational diabetes who delivered at 37 weeks or later and had a sonographic examination performed between 31 weeks and 36 weeks 6 days. Sonographic examinations were categorized as "early" if performed at 31 weeks to 33 weeks 6 days or "late" if performed at 34 weeks to 36 weeks 6 days. We estimated birth weight using the gestation-adjusted projection method, compared errors in prediction of birth weight using the t test and Mann-Whitney U test, and performed a 2-sample test of proportions to compare prediction of macrosomia (birth weight >4000 g). RESULTS: The early and late groups had similar mean gestational ages at birth (38 weeks 4 days versus 38 weeks 5 days; P = .13) and rates of macrosomia (10.7% versus 12.4%; P = .63). The early group had a greater mean absolute error (336 versus 297 g; P = .03) and percent error (9.9% versus 7.9%; P = .01) in birth weight prediction but a lower mean birth weight (3303 versus 3426 g; P = .02). Sensitivity for prediction of macrosomia was 19% in the early group versus 45% in the late group (P = .07), whereas specificity was similar (98% versus 96%; P = .27). CONCLUSIONS: Using the gestation-adjusted projection method in our patients with diabetes, we found that sonographic examinations performed at 34 weeks to 36 weeks 6 days better predicted birth weight than those performed at 31 weeks to 33 weeks 6 days.