Placenta accreta spectrum: the pattern and character of intraplacental blood flow by color and spectral Doppler.

PURPOSE: To characterize intraplacental blood flow patterns in placenta accreta spectrum (PAS) with color and spectral Doppler imaging. METHODS: Thirty-two patients at risk for PAS underwent ultrasound imaging with both color and spectral Doppler. The placenta was inspected for areas of vascularity by color Doppler, particularly within the lower uterine segment. Spectral Doppler waveforms were obtained from these vessels and categorized as either intraplacental or subplacental (myometrial), venous or arterial, fetal or maternal (based on heart rate). Arterial waveforms were measured for heart rate, peak systolic velocity, end diastolic velocity, and resistive index. Statistical comparisons were made between cases with and without PAS using Fisher exact tests (categorical variables) and Mann-Whitney U tests (numerical indices). Interobserver agreement was characterized with kappa coefficients. RESULTS: At delivery, there were 19 cases with PAS and 13 without PAS. On ultrasound studies, clustered intraplacental vascularity was found in the lower uterine segment in 66% of cases (95% of PAS cases and 23% cases without PAS; p < 0.0001). Maternal arterial waveforms were found within the vascular cluster in 84% of PAS cases and 15% of cases without PAS (p < 0.0001). A traversing fetal artery was found within the vascular cluster in 56% of cases (84% PAS cases and 15% cases without PAS; p = 0.001). Venous waveforms were found in 84% of PAS cases and 15% of cases without PAS. Interobserver agreement was good to excellent. CONCLUSION: Intraplacental blood flow pattern in PAS is characterized by an intraplacental vascular cluster containing low-resistance maternal arterial flow and transplacental fetal arteries.

Weight gain in pregnancy: can metformin steady the scales?

OBJECTIVE: Metformin has been associated with modest weight reduction in the non-pregnant population. Our hypothesis is that metformin exposure will lead to a higher incidence of appropriate weight gain during pregnancy. STUDY DESIGN: This was a retrospective cohort study in a single center between 2009 and 2019. We included all pregnant women with type 2 diabetes or prediabetes. We compared women exposed to metformin in any trimester. The primary outcome was appropriate weight gain defined by the Institute of Medicine guidelines. Secondary outcomes included excessive weight gain, weight loss, suspected fetal growth restriction (FGR), and mean birth weight. Adjusted odds ratios or group differences were calculated using logistic or linear regression, controlling for confounders. RESULTS: Of 41,472 deliveries during the study period, 511 pregnancies met inclusion criteria. 284 pregnancies had no metformin exposure; 227 did have metformin exposure, of which 169 (72.2%) were initiated on metformin in the first trimester. Women exposed to metformin in any trimester were statistically not more likely to have appropriate weight gain (aOR 1.53 (95% CI 1.00-2.34, p = .048), but did have less excess weight gain (aOR 0.45, 95% CI 0.30-0.66, p < .001), and more maternal weight loss (aOR 2.17, 95% CI 1.18-3.98, p = .012) than the unexposed group. Women exposed to metformin in the first trimester of pregnancy were less likely to have excess weight gain (aOR 0.39, 95% CI 0.25-0.61, p < .001) and more likely to have maternal weight loss (aOR 2.56, 95% CI 1.30-5.07, p = .007) than the unexposed cohort. There was no difference in FGR (5.3% vs 2.5% p = .094) or mean birth weight (3235.6 vs 3352.4 gm p = .122) in the metformin exposed group vs non-exposed groups, respectively. CONCLUSIONS: Metformin exposure in pregnancy was associated with less excess weight gain and a higher rate of weight loss. There was no difference in FGR or mean birth weight in metformin exposed neonates. This suggests that metformin may help avoid excess weight gain and its associated comorbidities.

Terbutaline-triggered fetal arrhythmia prior to neonatal diagnosis of Wolff-Parkinson-White syndrome: A case report.

INTRODUCTION: Short-term maternal administration of betamimetics is a common obstetric practice with uses including tocolysis during antenatal corticosteroid administration for fetal lung maturity, intrapartum tachysystole, and prior to external cephalic version. While previous research has demonstrated adverse effects of prolonged use of maternal betamimetics, no prior documentation exists of fetal tachyarrhythmias beyond sinus tachycardia after administration of terbutaline. CASE: This case documents a transient fetal tachyarrhythmia consistent with presumed atrial flutter after maternal administration of terbutaline for external cephalic version. On day of life 9, the neonate presented in supraventricular tachycardia with signs of heart failure and was subsequently diagnosed with Wolff-Parkinson-White syndrome. CONCLUSION: Maternal administration of terbutaline may be associated with transient fetal tachyarrhythmia. In some fetuses, this cardiac arrhythmia may predate diagnosis of an underlying cardiac disorder, warranting close follow-up after delivery.

The impact of insurance on equitable access to non-invasive prenatal screening (NIPT): private insurance may not pay.

Non-invasive prenatal testing (NIPT), is a prenatal screening test for chromosomal aneuploidies (trisomy 21, trisomy 18, and trisomy 13). While women under 35 years of age with no other risk factors are considered low risk for pregnancies with aneuploidy, most babies with aneuploidy are born to low-risk women. Across the USA, including Wisconsin, many private insurances do not cover initial NIPT for low-risk women, creating a potential financial burden that may limit patient selection of NIPT. Low-risk women with public insurance in Wisconsin are covered for NIPT. This pilot study determined if a difference exists in NIPT uptake based on insurance type in low-risk pregnant women in their first trimester. It also explored genetic counselor perspectives on how insurance coverage for NIPT is addressed with patients. Women with public insurance were 3.43 times more likely to have NIPT as an initial screen for aneuploidy than women with private insurance, indicating that insurance coverage may present a barrier to care. Additionally, analysis showed no evidence of different demographic variables interacting with another to impact outcome after allowing for insurance coverage (X214 = 14.301, p = 0.428). Our data also suggests that more genetic counselors would recommend NIPT to patients if insurance coverage was not a barrier and were more likely to discuss financial risks associated with NIPT when a patient had private insurance. We conclude that some women cannot choose one of the safest and most sensitive prenatal aneuploidy screening tests due to financial barriers put into place by the lack of insurance coverage.

A Matter of Time: Does Gestational Age Affect the Duration of the Fetal Anatomic Survey?

OBJECTIVE: To assess the average duration of detailed fetal anatomic surveys in pregnancy in relation to gestational age (GA) and the maternal body mass index (BMI) to determine optimal timing of the examination. METHODS: This was a retrospective cohort study of gravidae presenting for detailed fetal anatomic examinations between January 1, 2010, and June 30, 2017. After excluding examinations expected to have longer duration (ie, multifetal, major fetal anomalies), there were a total of 6522 examinations performed between GAs of 18 weeks 0 days and 22 weeks 0 days. Women were grouped by BMI, and results were analyzed by logistic regression. RESULTS: Gravidae of normal weight (BMI, 18.5-24.9 kg/m2 ) had a decrease of 47.47 seconds of the examination time with each increasing week of gestation (P = .036). Overweight (BMI, 25-29.9 kg/m2 ) gravidae similarly had a decrease of 66.31 seconds of the examination time with each additional week of gestation (P = .017). Underweight (BMI, 8.5 kg/m2 ) and obese (BMI, ≥30 kg/m2 ) gravidae did not have differences in the examination time with increasing GA. Increases in suboptimal examinations were noted with an increasing BMI (P < .001). There was a decreased frequency of suboptimal examinations in obese gravidae with a BMI of 40 kg/m2 or higher with increasing GA (P = .037). CONCLUSIONS: The duration of detailed fetal anatomic examinations decreased with increasing GA in normal-weight and overweight gravidae but not in obese gravidae. Performing the anatomy scan earlier in class I and II obese gravidae (BMI, 30-40 kg/m2 ) may enable improved pregnancy management options without increasing the examination duration or likelihood of a suboptimal evaluation.

Ultrasound Based Computational Fluid Dynamics Assessment of Brachial Artery Wall Shear Stress in Preeclamptic Pregnancy.

PURPOSE: Preeclampsia (PE) is a pregnancy complication of abnormally elevated blood pressure and organ damage where endothelial function is impaired. Wall shear stress (WSS) strongly effects endothelial cell morphology and function but in PE the WSS values are unknown. WSS calculations from ultrasound inaccurately assume cylindrical arteries and patient specific computational fluid dynamics (CFD) typically require time-consuming 3D imaging such as CT or MRI. METHODS: Two-dimensional (2D) B-mode ultrasound images were lofted together to create simplified three-dimensional (3D) geometries of the brachial artery (BA) that incorporate artery curvature and non-circular cross sections. This process was efficient and on average took 120 ± 10 s. Patient specific CFD was then performed to quantify BA WSS for a small cohort of PE (n = 5) and normotensive pregnant patients (n = 5) and compared against WSS calculations assuming a cylindrical artery. RESULTS: For several WSS metrics (time averaged WSS (TAWSS), peak systolic WSS, oscillatory shear index (OSI), OSI/TAWSS and relative residence time) CFD on the simplified arterial geometries calculated large spatial differences in WSS that assuming a cylindrical artery cannot calculate. Bland-Altman and intra-class correlation (ICC) analyses found assuming a cylindrical artery both underestimated (p < 0.05) and had poor agreement (ICC < 0.5) with the maximum WSS values from CFD. WSS values that were abnormal compared to the normotensive patients (OSI = 0.014 ± 0.026) appear related to the pregnancy complications fetal growth restriction (n = 2, OSI = 0.14, 0.25) and gestational diabetes (n = 1, OSI = 0.23). CONCLUSION: Creating 3D artery geometries from 2D ultrasound images can be used for CFD simulations to calculate WSS from ultrasound without assuming cylindrical arteries. This approach requires minimal time for both medical imaging and CFD analysis.

Detailed Fetal Anatomic Ultrasound Examination Duration and Association With Body Mass Index.

OBJECTIVE: To evaluate the association of the duration of the detailed fetal anatomic ultrasound examination with maternal body mass. METHODS: This was a retrospective chart review of patients presenting to our clinic for detailed fetal anatomic examinations between January 1, 2010, and June 30, 2017. After excluding multifetal pregnancies and other examinations expected to have a longer duration, a total of 6,522 examinations were performed between 18 0/7 and 22 0/7 weeks of gestation. Results were analyzed using analysis of variance and Student's t-test. RESULTS: Mean (SD) body mass index (BMI) was 29.3 (±7.7), and mean examination time was 51.5 (±10.4) minutes. We found that mean examination time was 48.8 (±9.6) minutes for patients with normal BMIs, 50.6 (±10.0) minutes for overweight patients, 52.2 (±10.4) minutes for patients with class I obesity, 54.6 (±10.3) minutes for patients with class II obesity, and 57.7 (±10.3) minutes for patients with class III obesity (P<.001). The duration of the detailed fetal anatomic ultrasound examination increased continuously with BMI (r=0.285, P<.001). CONCLUSION: We found that the duration of detailed fetal anatomic examinations increased with BMI. Examinations for gravid patients with class III obesity lasted 8.9 minutes longer than those for gravid patients with normal BMIs; examinations for gravid patients with BMIs of 50 or higher lasted 13.5 minutes longer. This information may be useful for fetal ultrasound examination scheduling.

Operative Vaginal Delivery Is a Safe Option in Women Undergoing a Trial of Labor after Cesarean.

Objective To compare outcomes of operative intervention in the second stage of labor during trial of labor after cesarean (TOLAC). Study Design A secondary analysis of the Maternal-Fetal Medicine Units Network cesarean section registry was conducted. Analysis was by first attempted mode of delivery. Results A total of 1,837 met inclusion criteria. Subjects in the operative vaginal groups (OVDs) were more likely to have a prior vaginal delivery (vacuum 34.2%; forceps 34.3%) than the repeat cesarean delivery (RCD) group (22.6%; p < 0.0001). Most OVD attempts were successful (forceps 90.4%; vacuum 92.6%). Neonatal morbidity was not different (12.1% forceps vs. 14.6% vacuum; 14.8% RCD). Maternal morbidity was highest among forceps deliveries (32.3 vs. 24.3% vacuum; 22.0% RCD, p = 0.0001). RCD was associated with surgical injury (2.7 vs. 0.7% forceps; 0% vacuum; p < 0.0001), endometritis (8.4 vs. 3.2% forceps, 1.2% vacuum; p < 0.0001), and wound complications (1.9 vs. 0.4% forceps; 0.3% vacuum; p = 0.006). OVD was associated with anal sphincter laceration (22.7% forceps, 15.5% vacuum; 0% RCD; p = 0.01). Conclusion The success rate of OVD is high in TOLAC with similar outcomes to RCD. Maternal composite outcomes were highest with forceps-assisted vaginal deliveries. However, considering overall morbidity, OVD in the second stage of labor in TOLAC is a reasonable, safe option in selected cases.

Structured Training for Fetal Diagnostic Skills in a Maternal-Fetal Medicine Fellowship.

Objective The American Institute of Ultrasound in Medicine has described what constitutes a detailed fetal anatomic examination but what comprises an appropriate physician training program has not been described. The purpose of this paper is to describe a highly-structured program developed by our center to train maternal-fetal medicine fellows in a systematic approach to fetal diagnostic imaging. Study Design We describe this approach in three phases. Phase I: Development of Skills as a Perinatal Sonographer, Phase II: Mentored Evolution to a Perinatal Sonologist and Phase III: Supervised Independent Practice as Consultant-in-training. Results This curriculum was implemented in 2006. Of the eight maternal-fetal medicine fellows who completed this program, 100% were capable of following this curriculum and 100% felt comfortable performing and interpreting detailed sonograms including sonograms with significant and uncommon anomalies. Qualitative feedback was also positive. Finally, this structured approach resulted in an increase in the average total number of sonograms interpreted. Conclusion Our curriculum, by following the explicit guidelines and expectations set out by the American Institute of Ultrasound in Medicine and the American Board of Obstetrics and Gynecology for practicing maternal-fetal medicine fellowship graduates, provides an opportunity to explore national standardization for this component of training.

Travel During Pregnancy: Considerations for the Obstetric Provider.

IMPORTANCE: Travel among US citizens is becoming increasingly common, and travel during pregnancy is also speculated to be increasingly common. During pregnancy, the obstetric provider may be the first or only clinician approached with questions regarding travel. OBJECTIVE: In this review, we discuss the reasons women travel during pregnancy, medical considerations for long-haul air travel, destination-specific medical complications, and precautions for pregnant women to take both before travel and while abroad. To improve the quality of pretravel counseling for patients before or during pregnancy, we have created 2 tools: a guide for assessing the pregnant patient's risk during travel and a pretravel checklist for the obstetric provider. EVIDENCE ACQUISITION: A PubMed search for English-language publications about travel during pregnancy was performed using the search terms "travel" and "pregnancy" and was limited to those published since the year 2000. Studies on subtopics were not limited by year of publication. RESULTS: Eight review articles were identified. Three additional studies that analyzed data from travel clinics were found, and 2 studies reported on the frequency of international travel during pregnancy. Additional publications addressed air travel during pregnancy (10 reviews, 16 studies), high-altitude travel during pregnancy (5 reviews, 5 studies), and destination-specific illnesses in pregnant travelers. CONCLUSIONS AND RELEVANCE: Travel during pregnancy including international travel is common. Pregnant travelers have unique travel-related and destination-specific risks. We review those risks and provide tools for obstetric providers to use in counseling pregnant travelers.

A transcervical chorionic villus sampling model for teaching.

We sought to create a transcervical chorionic villus sampling model for teaching that would mimic a lifelike model. A model was created using silicone resembling the maternal interface. A cervix with an endocervical canal able to accommodate a catheter and a vagina was also created. Tap water was used as the amniotic fluid. Chorionic villus sampling was accomplished using this model with the actual ultrasound machines and environment as in the real model. This simulator allowed placental placement in different locations to increase the difficulty level as well as angulations and catheter handling. Given the low cost (less than $200), this model could be used indefinitely in a relaxed and controlled environment.