Obesity in prenatal medicine: a game changer?

Obesity is recognized by the World Health Organization (WHO) as a disease in its own right. Moreover, obesity is an increasingly concerning public health issue across the world and its prevalence is rising amongst women of reproductive age. The fertility of over-weight and obese women is reduced and they experience a higher rate of miscarriage. In pregnant women obesity not only increases the risk of antenatal complications, such as preeclampsia and gestational diabetes, but also fetal abnormalities, and consequently the overall feto-maternal mortality. Ultrasound is one of the most valuable methods to predict and evaluate pregnancy complications. However, in overweight and obese pregnant women, the ultrasound examination is met with several challenges, mainly due to an impaired acoustic window. Overall obesity in pregnancy poses special challenges and constraints to the antenatal care and increases the rate of pregnancy complications, as well as complications later in life for the mother and child.

Importance of a detailed anomaly scan after a cfDNA test indicating fetal trisomy 21, 18 or 13.

OBJECTIVE: To investigate the effect of the presence or absence of fetal anomalies and soft markers diagnosed by ultrasound on positive predictive value (PPV) 21, 18 and 13 in pregnancies with a high-risk cfDNA result. METHODS: Retrospective study including singleton pregnancies with high-risk NIPT results for common trisomies followed by invasive testing. The cases were grouped by gestational age at the time of invasive testing and by the presence or absence of fetal abnormalities or soft markers. The ultrasound was considered abnormal if at least one major defect or a soft marker was detected. RESULTS: A total of 173 women were included. Median maternal and gestational age was 37.7 years and 14.0 weeks, respectively. CfDNA test result showed high-risk for trisomy 21 and trisomy 18 or 13 in 119 and 54 cases, respectively. The "pre-ultrasound" PPV for trisomy 21 and for trisomy 18 or 13 were 98.3% and 68.4%, respectively. In case of a high-risk result for trisomy 21 and no fetal anomalies, the PPV was 86.7% while it was 100% if there were anomalies or markers present. In the case of a high-risk result for trisomy 18 or 13, the PPV was 9.5% if the ultrasound examination was normal and 100% if the ultrasound examination was abnormal. CONCLUSION: This study suggests that a detailed ultrasound examination performed after a cfDNA result that is high-risk for one of the common autosomal trisomies adds significantly to establishing an individualized risk assessment. This is particularly true in cases with a high-risk result for trisomies 18 or 13.

How to do a 3D uterus ultrasound?

Three-dimensional (3D) ultrasound is an invaluable tool in the detection and evaluation of many uterine anomalies and improves upon the traditional approach of two-dimensional (2D) ultrasonography. We aim to describe an easy way of assessing the uterine coronal plane using the basic three-dimensional ultrasound in everyday gynecological practice.

How to do a second trimester anomaly scan.

A systematic evaluation of the fetal anatomy as part of the second trimester ultrasound examination in pregnancy is useful in detecting pregnancy complications, fetal abnormalities, and genetic diseases. We aim to illustrate the basic and detailed second trimester scan, according to current international and national guidelines, as well as to our own every-day practice in the Department for Prenatal Diagnosis at the University of Tübingen, Germany.

Bi-allelic loss-of-function variants in KIF21A cause severe fetal akinesia with arthrogryposis multiplex.

BACKGROUND: Fetal akinesia (FA) results in variable clinical presentations and has been associated with more than 166 different disease loci. However, the underlying molecular cause remains unclear in many individuals. We aimed to further define the set of genes involved. METHODS: We performed in-depth clinical characterisation and exome sequencing on a cohort of 23 FA index cases sharing arthrogryposis as a common feature. RESULTS: We identified likely pathogenic or pathogenic variants in 12 different established disease genes explaining the disease phenotype in 13 index cases and report 12 novel variants. In the unsolved families, a search for recessive-type variants affecting the same gene was performed; and in five affected fetuses of two unrelated families, a homozygous loss-of-function variant in the kinesin family member 21A gene (KIF21A) was found. CONCLUSION: Our study underlines the broad locus heterogeneity of FA with well-established and atypical genotype-phenotype associations. We describe KIF21A as a new factor implicated in the pathogenesis of severe neurogenic FA sequence with arthrogryposis of multiple joints, pulmonary hypoplasia and facial dysmorphisms. This hypothesis is further corroborated by a recent report on overlapping phenotypes observed in Kif21a null piglets.

A single center experience of prenatal parent-fetus trio exome sequencing for pregnancies with congenital anomalies.

OBJECTIVES: To examine the diagnostic yield of trio exome sequencing in fetuses with multiple structural defects with no pathogenic findings in cytogenetic and microarray analyses. METHODS: We recruited 51 fetuses with two or more defects, non-immune fetal hydrops or fetal akinesia deformation syndrome|or fetal akinesia deformation sequence (FADS). Trio exome sequencing was performed on DNA from chorionic villi samples and parental blood. Detection of genomic variation and prioritization of clinically relevant variants was performed according to in-house standard operating procedures. RESULTS: Median maternal and gestational age was 32.0 years and 21.0 weeks, respectively. Forty-three (84.3%) fetuses had two or more affected organ systems. The remaining fetuses had isolated fetal hydrops or FADS. In total, the exome analysis established the genetic cause for the clinical abnormalities in 22 (43.1%, 95% CI 29.4%-57.8%) pregnancies. CONCLUSIONS: In fetuses with multiple defects, hydrops or FADS and normal standard genetic results, trio exome sequencing has the potential to identify genetic anomalies in more than 40% of cases.

Universal Cell Free DNA or Contingent Screening for Trisomy 21: Does It Make a Difference? A Comparative Study with Real Data.

OBJECTIVE: The aim of the objective was to compare the detection rate for trisomy 21 of universal cell free DNA (cfDNA) screening with contingent screening. METHODS: Retrospective study was carried out at 3 German centers. The study included euploid and trisomy 21 pregnancies where cfDNA and first trimester (FT) screening assessment was carried out. The FT risk for trisomy 21 was computed based on combined screening and stratified into the following classes: high risk ≥1:10, intermediate risk 1:11-1,000, low risk ≤1,001. For universal cfDNA screening, the cfDNA test results were examined. For the contingent screening model, the result of the cfDNA test was taken into account in case of an intermediate FT risk. Different strategies combining maternal age, nuchal translucency, nasal bone, beta-hCG, and PAPP-A were evaluated. Screen positivity was defined as either a high risk after FT screening or a cfDNA test indicating a high-risk result. An inconclusive cfDNA test was also considered as screen positive. RESULTS: The search of the database identified 2,255 euploid and 163 affected pregnancies. All affected fetuses were identified by universal cfDNA screening. 1.3% of the euploid fetuses were classified as screen positive due to final inconclusive cfDNA test result. The detection and false-positive rate of a contingent approach that is based on combined screening and cfDNA screening in the intermediate group would be 98.4% and 0.7%, respectively. With this approach, cfDNA screening would be necessary in only about 27% of all pregnancies. CONCLUSION: This study demonstrates that a contingent approach provides similar detection rates for trisomy 21 as universal cfDNA screening, by a reduction of 73% the number of cfDNA tests.

Measurement of the uterocervical angle for the prediction of preterm birth in symptomatic women.

PURPOSE: To examine if the uterocervical angle (UCA) can be used to predict preterm delivery in women with painful and regular uterine contractions and a cervical length of 25 mm or less. METHODS: Retrospective study at the perinatal unit of the University Hospital of Tuebingen, Germany. Women with singleton gestation and preterm contractions between 24 + 0 and 33 + 6 weeks' gestation were included. For the UCA measurement, a line is placed from the internal os to the external os irrespective of whether the cervix is straight or curved. A second line is drawn to delineate the lower uterine segment. The angle between the two lines is the UCA measurement. The measurements were taken on stored images from our database. RESULTS: The study consisted of 213 singleton pregnancies. At the time of UCA measurement, median maternal and gestational age was 31.4 years and 29.7 weeks' gestation. Median gestational age at delivery was 35.3 weeks and the corresponding birth weight 2480 g, respectively. The UCA measurement in women who delivered within 2 days, between 3-7 days and after 7 days was not helpful to distinguish between these three groups [median UCA measurements: 108.5°, 108.0° and 107.3° (Kruskal-Wallis test p = 0.576)]. Uni- and multivariate logistic multiple regression analysis demonstrated that the delivery within 2 days was only dependent on the gestational age and the cervical length at the time of presentation. CONCLUSION: The measurement of UCA is not useful in predicting preterm birth in the subsequent 7 days after an episode of preterm contractions.

First Trimester Screening for Common Trisomies and Microdeletion 22q11.2 Syndrome Using Cell-Free DNA: A Prospective Clinical Study.

OBJECTIVES: The aims of the study were to assess the false-positive and uninformative test rate with first trimester cell-free DNA (cfDNA) screening for common trisomies and microdeletion 22q11.2 (22q11.2DS) and to examine women's attitudes toward such an approach. METHODS: This is a prospective study at the Prenatal Medicine Department of the University of Tübingen, Germany, at 11-13 weeks. In all pregnancies, a detailed ultrasound examination was carried out, followed by a cfDNA analysis for common trisomies and 22q11.2DS. In cases where the cfDNA analysis indicated 22q11.2DS, invasive prenatal diagnostic testing and parental testing were performed. After delivery, a detailed neonatal clinical examination was carried out including further genetic testing. Prior to counselling about the study, we asked the pregnant women who were potentially eligible for the study to anonymously report on their knowledge about 22q11.2DS. RESULTS: A total of 1,127 pregnancies were included in the final analysis of the study. The first cfDNA test was uninformative in 15 (1.33%) pregnancies. In 10 (0.89%) cases, the test remained uninformative, even after the second blood sample. There were 3 (0.27%) cases with a positive cfDNA test for 22q11.2DS. In all, 983 women returned the anonymous questionnaire prior to study participation. Only 80 (8.1%) women responded that they felt familiar or very familiar with 22q11.2DS. CONCLUSION: The addition of 22q11.2DS in first trimester cfDNA screening for common trisomies is feasible. The uninformative test rate for common trisomies and 22q11.2DS is 0.9%, and the false-positive rate for 22q11.2DS is 0.3%. Awareness and education around 22q11.2DS should be improved.

Fetal profile in fetuses with open spina bifida.

OBJECTIVE: To determine whether the frontomaxillary facial (FMF) angle and the prefrontal space ratio (PFSR) are helpful in screening for open spinal defects by ultrasound in the second and third trimesters of pregnancy. METHODS: The FMF angle and the PFSR were measured in fetuses with spina bifida according to standardized protocols. The normal range of the PFSR was previously published by our group. To determine the normal values for the FMF angle in the second and third trimesters of pregnancy, we used the same stored images from the above-mentioned study. RESULTS: 71 affected and 279 normal fetuses were included in this study. Median gestational ages in the two groups were 21.1 weeks and 21.6 weeks, respectively. In fetuses with spina bifida, the FMF angle was significantly smaller than in the normal population (72.9° versus 79.6°). However, the measurement was below the fifth centile in only 22.5% of the affected fetuses. The PFSR was similar in both groups. CONCLUSIONS: The FMF angle is smaller in second and third trimester fetuses with open spina bifida. However, the difference is not large enough to implement this marker in current screening programs.

First trimester uterine artery pulsatility index levels in euploid and aneuploid pregnancies.

OBJECTIVE: To examine whether the uterine artery PI is different in aneuploid and euploid pregnancies. METHODS: Retrospective case-matched study at the department of prenatal medicine at the University of Tuebingen, Germany. The study involved patients with complete data on first trimester screening for trisomies and preeclampsia except PlGF. For each case with trisomy 21 we randomly selected 50 cases with a euploid fetus where complete data on screening for aneuploidy and preeclampsia were also available. The uterine artery pulsatility index and the corresponding MoM values of euploid and the aneuploid population were compared with a Man-Whitney U test. RESULTS: The dataset consisted of 4591 singleton pregnancies. The karyotype was normal in 4500 cases and was abnormal in the remaining 91 pregnancies. There were 50 pregnancies with trisomy 21, 31 with trisomy 18 and 13, and 10 with triploidy. In the group with euploid fetuses, median uterine artery PI was 1.55 (0.99 MoM). In the group with trisomy 21, the median PI (1.42) and MoM (0.89) levels were both significantly lower than in the euploid (p < 0.001). However, the measurements in the trisomy 18 and 13 [1.61 (0.93 MoM)] and in the triploidy [1.99 (1.13 MoM)] groups were not significantly different from those in the euploid group (p = 0.468 and p = 0.632, respectively). CONCLUSION: In conclusion, uterine artery PI levels in the first trimester are slightly lower in pregnancies with trisomy 21. This knowledge may prove to be useful in cases where a low PAPP-A level is seen on the first trimester maternal serum biochemical evaluation to differentiate whether the more likely cause for this finding is placental dysfunction or aneuploidy, specifically trisomy 21.

Splenic artery blood flow as a potential marker for materno-fetal transmission of a primary CMV infection.

OBJECTIVE: To examine the blood flow in the splenic artery as marker for materno-fetal transmission at about 20 weeks following a maternal first-trimester primary CMV infection. METHODS: This is a retrospective study at the prenatal medicine unit at University of Tuebingen, Germany. Women were included who underwent an amniocentesis to examine the fetal infection status following a maternal primary CMV infection in the first trimester. In all cases, amniocentesis was done at about 20 weeks and at least 6 weeks after the maternal infection. As part of the detailed ultrasound examination prior to each amniocentesis, we examined the peak systolic velocity flow (PSV) and the pulsatility index (PI) of the splenic artery. Measurements were transformed into MoMs according to the normal curves of Ebbing et al. RESULTS: 81 Women fulfilled the inclusion criteria. Maternal and gestational age was 31.9 years and 20.6 weeks' gestation. Maternal-fetal transmission occurred in 13 of the cases. In fetuses without and with a CMV infection, mean PI was 0.98 MoM and 0.89 (p = 0.081). Mean PSV was significantly higher in the group of infected fetuses than in those without (1.24 vs. 0.94 MoM, p = 0.026). CONCLUSION: The PSV may be a marker for maternal-fetal CMV transmission following a first-trimester maternal infection.

False-positive rates in screening for trisomies 18 and 13: a comparison between first-trimester combined screening and a cfDNA-based approach.

PURPOSE: To determine the false-positive rates (FPR) associated with screening for trisomy 18/13 using first-trimester combined screening (FTCS) and an ultrasound plus cfDNA-based approach (US-cfDNA), which includes a detailed ultrasound examination, a cfDNA analysis and a FTCS reflex backup test for cases with uninformative results. METHODS: This is a sub-analysis of a randomized controlled trial, which was performed between 2015 and 2016. Pregnant women with a normal first-trimester ultrasound examination at 11-13 weeks' gestation (NT < 3.5 mm, no anomalies) were randomized into two groups: FTCS and US-cfDNA screening. The overall FPR in screening for trisomies 18/13 and 21 was compared with the FPR in screening for trisomy 21 alone. Pregnancies were considered screen positive if the risk for trisomy 21 was 1:100 and for trisomy 18 and 13, 1:20 each. RESULTS: The study population consisted of 688 pregnancies in each study arm. In the FCTS group, median delta NT was 0.0 mm, free beta-hCG and PAPP-A 0.96 and 1.11 MoM. In the US-cfDNA group, median delta NT was 0.0 mm. In 10 pregnancies, the cfDNA analysis was uninformative. In the FTCS and in the US-cfDNA group, the FPR in screening for trisomy 21 was 2.5% and 0%. In both groups, the overall FPR was not increased by adding screening algorithms for trisomies 18 and 13. CONCLUSION: In conclusion, the addition of screening for trisomies 18 and 13 to screening for trisomy 21 does not significantly change FPR. This is true for both the FTCS and the US-cfDNA-based approach.

Dosing interval between mifepristone and misoprostol in second and third trimester termination.

OBJECTIVE: To compare several strategies for second trimester labor induction for termination of pregnancy (TOP) using misoprostol and mifepristone and to determine which one is more effective in accelerating the time to delivery. METHOD: This was a retrospective study in which pregnancies that underwent second and third trimester TOP due to fetal anomalies between 2007 and 2017 were classified into a group that received misoprostol alone, a group that received mifepristone followed by misoprostol on the same day, one where misoprostol was given 1 day after mifepristone and one where the medications were administered 2 days apart. The primary outcome measure was the induction to delivery interval. RESULTS: 481 pregnancies fulfilled the inclusion criteria. In 140 cases, mifepristone was not administered. 341 women received mifepristone prior to induction, which was administered on the day of induction in 85 cases, and 1 or 2 days prior to induction in 140 and 19 cases. Median time interval between first induction and delivery was 15.0 (IQR 10.0-24.1) h in case no mifepristone was given and 13.2 (9.7-18.2) h if mifepristone was given on the same day and 9.3 (6.6-14.9) and 10.5 (7.2-22.3) h, if mifepristone was given 1 or 2 days prior to induction. After 24 h, the proportion of terminated pregnancies in each of the four groups was 75.0, 83.5, 93.2 and 78.9%. CONCLUSION: A 1 day interval between mifepristone and misoprostol is more effective in second and third trimester TOP compared to other strategies in terms of reducing the induction to abortion interval.

Changes in the Detection and Management of Foetal Trisomies over Time.

Introduction This study investigates whether the time of diagnosis of foetal trisomy 21/18/13 and the frequency of termination of pregnancy have changed in the past 10 years. Material and Methods Retrospective study at the Tübingen University Centre for Women's Health in which the cases with ante- and postnatal diagnosis of trisomy were investigated. A prerequisite was that the patients be examined in the antenatal medicine department. The time of diagnosis, the frequency of termination of pregnancy and the gestational age in the case of a termination were assessed. Results Between 2007 and 2017, trisomy 21/18/13 was diagnosed in 498 foetuses and newborns. In 311 of the foetuses or newborns, trisomy 21 was identified; in 134, trisomy 18; and in 53, trisomy 13. The median gestational age at diagnosis in the case of foetuses with trisomy 21 was between 14.4 and 13.6 weeks of pregnancy. The rate of pregnancy terminations increased slightly from 66.7% between 2007 and 2010 to 75.5% between 2015 and 2017. The median gestational age at the time of termination remained constant at 14.9 and 15.0 weeks of pregnancy respectively. The median gestational age at diagnosis in the case of foetuses with trisomy 18/13 was between 13.6 and 14.6 weeks of pregnancy during the examination period. The percentages of affected pregnancies which were terminated in the three time periods increased slightly from 57.4 to 69.0%. The gestational age remained unchanged in this case at 15.0 and 15.1 weeks of pregnancy respectively. Conclusion The time of intrauterine diagnosis of trisomy 21/18/13 has not changed in the past 10 years. The frequency of termination of a pregnancy increased slightly and the time of termination remained unchanged.

First trimester screening for major cardiac defects based on the ductus venosus flow in fetuses with trisomy 21.

OBJECTIVE: To examine whether in fetuses with trisomy 21 (T21), the ductus venosus (DV) flow differs in presence of a major cardiac defect (congenital cardiac defect [CHD]) and whether this affects the risk distribution in first trimester screening for T21. METHODS: This retrospective study included pregnant women who underwent first trimester screening. This involves an examination of the crown-rump length, the nuchal translucency, the ductus venosus (DV) flow, and the heart. Three groups of fetuses were examined: euploid without CHD, T21 with CHD, and T21 without CHD. We examined the DV pulsatility index for veins, the direction of the a-wave, and ratios of velocities: v/S, v/D, a/S, a/D, and S/D. RESULTS: The study population consisted of 410 euploid fetuses and 136 with T21 (51 with CHD and 85 without CHD). In the 3 groups, the a-wave was reversed in 3.2%, 66.7%, and 57.6%. The DV flow ratios in T21 with and without CDH were significantly different compared with normal fetuses. When comparing the ratios between the 2 T21 groups, only the a/S and a/D ratio were significantly different. The risk distributions in screening for T21 with and without CDH were similar. CONCLUSION: There are some small differences in the DV flow of T21 fetuses with and without CHD, but they are not clinically useful.