The incremental yield of prenatal exome sequencing over chromosome microarray for congenital heart abnormalities: A systematic review and meta-analysis

OBJECTIVES

To determine the incremental yield of prenatal exome sequencing (PES) over standard testing in fetuses with an isolated congenital heart abnormality (CHA), CHA associated with extra-cardiac malformations (ECMs) and CHA dependent upon anatomical subclassification.

METHODS

A systematic review of the literature was performed using MEDLINE, EMBASE, Web of Science and grey literature January 2010-February 2023. Studies were selected if they included greater than 20 cases of prenatally diagnosed CHA when standard testing (QF-PCR/chromosome microarray/karyotype) was negative. Pooled incremental yield was determined. PROSPERO CRD 42022364747.

RESULTS

Overall, 21 studies, incorporating 1957 cases were included. The incremental yield of PES (causative pathogenic and likely pathogenic variants) over standard testing was 17.4% (95% CI, 13.5%-21.6%), 9.3% (95% CI, 6.6%-12.3%) and 35.9% (95% CI, 21.0%-52.3%) for all CHAs, isolated CHAs and CHAs associated with ECMs. The subgroup with the greatest yield was complex lesions/heterotaxy; 35.2% (95% CI 9.7%-65.3%). The most common syndrome was Kabuki syndrome (31/256, 12.1%) and most pathogenic variants occurred de novo and in autosomal dominant (monoallelic) disease causing genes (114/224, 50.9%).

CONCLUSION

The likelihood of a monogenic aetiology in fetuses with multi-system CHAs is high. Clinicians must consider the clinical utility of offering PES in selected isolated cardiac lesions.

Fetal central nervous system anomalies: When should we offer exome sequencing?

OBJECTIVE

To investigate the detection of pathogenic variants using exome sequencing in an international cohort of fetuses with central nervous system (CNS) anomalies.

METHODS

We reviewed trio exome sequencing (ES) results for two previously reported unselected cohorts (Prenatal Assessment of Genomes and Exomes (PAGE) and CUIMC) to identify fetuses with CNS anomalies with unremarkable karyotypes and chromosomal microarrays. Variants were classified according to ACMG guidelines and association of pathogenic variants with specific types of CNS anomalies explored.

RESULTS

ES was performed in 268 pregnancies with a CNS anomaly identified using prenatal ultrasound . Of those with an isolated, single, CNS anomaly, 7/97 (7.2%) had a likely pathogenic/pathogenic (LP/P) variant. This includes 3/23 (13%) fetuses with isolated mild ventriculomegaly and 3/10 (30%) fetuses with isolated agenesis of the corpus callosum. Where there were multiple anomalies within the CNS, 12/63 (19%) had LP/P variants. Of the 108 cases with CNS and other organ system anomalies, 18 (16.7%) had LP/P findings.

CONCLUSION

ES is an important tool in the prenatal evaluation of fetuses with any CNS anomaly. The rate of LP/P variants tends to be highest in fetuses with multiple CNS anomalies and multisystem anomalies, however, ES may also be of benefit for isolated CNS anomalies.

Cardiometabolic health after first pregnancy: Associations with social determinants of health. A nuMoM2b-HHS study

Study objective

This study sought to evaluate the associations between social determinants of health (SDOH) at the time of first pregnancy and subsequent cardiometabolic health, defined as the development of metabolic syndrome.

Design

nuMoM2b-HHS (Nulliparous Pregnancy Outcomes Study- Monitoring Mothers-to-Be-Heart Health Study) is an ongoing prospective cohort study.

Setting

Eight academic medical centers enrolled and continue to follow participants.

Participants

4484 participants followed a mean of 3.2 years from the time of their first pregnancy.

Interventions

N/a.

Main outcome measure

Unadjusted and adjusted Poisson regression models with robust standard errors were used to obtain relative risks and 95% confidence intervals estimating the risk of metabolic syndrome for each baseline SDOH. In secondary analyses we examined the associations between SDOH and incident hypertension, obesity, and diabetes mellitus.

Results

Metabolic syndrome developed in 13.6% of participants. Higher socioeconomic position at the time of pregnancy was associated with lower rates of metabolic syndrome [income > 200% poverty level aRR 0.55 (95% CI, 0.42-0.71), attainment of a bachelor's degree aRR 0.62 (0.46-0.84) or higher aRR 0.50 (0.35-0.71)], while being single [aRR 1.45 (95% CI, 1.18-1.77)] and having low health literacy were associated with a greater risk of metabolic syndrome [aRR 1.98 (95% CI, 1.28-3.07)].

Conclusions

Over a short interval following first pregnancy, participants accumulated high proportions of cardiovascular risk factors and metabolic syndrome, with some risk associated with SDOH. The impact of interventions addressing SDOH in pregnant people on cardiometabolic health should be tested as a means of reducing health inequities at the population level.

Investigating the mechanical function of the cervix during pregnancy using finite element models derived from high-resolution 3D MRI

Preterm birth is a strong contributor to perinatal mortality, and preterm infants that survive are at risk for long-term morbidities. During most of pregnancy, appropriate mechanical function of the cervix is required to maintain the developing fetus in utero. Premature cervical softening and subsequent cervical shortening are hypothesized to cause preterm birth. Presently, there is a lack of understanding of the structural and material factors that influence the mechanical function of the cervix during pregnancy. In this study we build finite element models of the pregnant uterus, cervix, and fetal membrane based on magnetic resonance imagining data in order to examine the mechanical function of the cervix under the physiologic loading conditions of pregnancy. We calculate the mechanical loading state of the cervix for two pregnant patients: 22 weeks gestational age with a normal cervical length and 28 weeks with a short cervix. We investigate the influence of (1) anatomical geometry, (2) cervical material properties, and (3) fetal membrane material properties, including its adhesion properties, on the mechanical loading state of the cervix under physiologically relevant intrauterine pressures. Our study demonstrates that membrane-uterus interaction, cervical material modeling, and membrane mechanical properties are factors that must be deliberately and carefully handled in order to construct a high quality mechanical simulation of pregnancy.

Nuchal Translucency Quality Review (NTQR) program: first one and half million results

OBJECTIVE

To evaluate the performance of first-trimester nuchal translucency (NT) measurement by providers (physician-sonologists and sonographers) within the Nuchal Translucency Quality Review (NTQR) program.

METHODS

After training and credentialing providers, the NTQR monitored performance of NT measurement by the extent to which an individual's median multiple of the normal median (MoM) for crown-rump length (CRL) was within the range 0.9-1.1 MoM of a published normal median curve. The SD of log10 MoM and regression slope of NT on CRL were also evaluated. We report the distribution between providers of these performance indicators and evaluate potential sources of variation.

RESULTS

Among the first 1.5 million scans in the NTQR program, performed between 2005 and 2011, there were 1 485 944 with CRL in the range 41-84 mm, from 4710 providers at 2150 ultrasound units. Among the 3463 providers with at least 30 scans in total, the median of the providers' median NT-MoMs was 0.913. Only 1901 (55%) had a median NT-MoM within the expected range; there were 89 above 1.1 MoM, 1046 at 0.8-0.9 MoM, 344 at 0.7-0.8 MoM and 83 below 0.7 MoM. There was a small increase in the median NT-MoM according to providers' length of time in the NTQR program and number of scans entered annually. On average, physician-sonologists had a higher median NT-MoM than did sonographers, as did those already credentialed before joining the program. The median provider SD was 0.093 and the median slope was 13.5%. SD correlated negatively with the median NT-MoM (r = -0.34) and positively with the slope (r = 0.22).

CONCLUSION

Even with extensive training, credentialing and monitoring, there remains considerable variability between NT providers. There was a general tendency towards under-measurement of NT compared with expected values, although more experienced providers had performance closer to that expected.

Application of three-dimensional ultrasonography in the evaluation of the fetal heart

The objectives of this study were to determine whether three-dimensional ultrasonography can provide more cardiac views than two-dimensional ultrasonography and to develop a standard technique. Eighteen women, 16 to 26 weeks' gestation, were scanned with two-dimensional ultrasonography for 10 minutes or less to obtain fetal heart views. Three-dimensional ultrasonography was used (< or =10 minutes) to obtain up to 4 acquisitions of the fetal heart: 4-chamber view, left parasagittal, transverse, and longitudinal nonstandard. Views were later extracted from saved volume data, comparing the yields of two- and three-dimensional ultrasonography. The 4-chamber view was obtained in 15 (93%) of 16 cases on both two- and three-dimensional ultrasonography. On two-dimensional ultrasonography, the left outflow tract was obtained in 68% of the cases; on three-dimensional ultrasonography, the left outflow tract was obtained in 46% from the 4-chamber view acquisition and in 100% from the left parasagittal acquisition. On two-dimensional ultrasonography, the right outflow tract was obtained in 68% of the cases; on three-dimensional ultrasonography, the right outflow tract was obtained in 86% from the 4-chamber view acquisition and in 71% from the left parasagittal acquisition. Aortic and ductal arches were obtained in 12% and 18%, respectively, on two-dimensional ultrasonography. On three-dimensional ultrasonography the aortic and ductal arches were obtained in 66% and 86%, respectively, from the 4-chamber view acquisition and in 57% and 71%, respectively, from the left parasagittal acquisition. Three-dimensional ultrasonography permitted a greater number of cardiac views to be extracted from volume data than did two-dimensional ultrasonography.

Maternal uniparental disomy of chromosome 16 and body stalk anomaly

We report on a fetus with placental trisomy 16, maternal uniparental disomy (UPD), and body stalk anomaly. Body stalk anomaly is a rare, fatal developmental abnormality consisting of a defective abdominal wall with abdominal organs in a sac outside the abdominal cavity covered by amnion adherent to the placenta with absence or severe shortness of the umbilical cord. Trisomy 16 was identified in the placenta in all cells. Amniocentesis was karyotypically normal. Parental origin studies showed maternal UPD for chromosome 16 in post-termination fetal tissue. The cause of the body stalk anomaly is not clearly defined. There are no other reports of placental karyotype or UPD investigations with body stalk anomaly. To our knowledge, this is the first report of placental trisomy 16, UPD in fetus, and body stalk anomaly, suggesting placental insufficiency or imprinting effects as cause of this anomaly. Am. J. Med. Genet. 94:284-286, 2000.

Diagnosis of conjoined twins at 10 weeks using three-dimensional ultrasound: a case report

A case report is presented of the prenatal diagnosis of conjoined twins at 10 weeks and 2 days' gestation using three-dimensional ultrasound (3D US). The multiplanar display coupled with 3D US surface rendering clearly confirmed the presence of craniopagus. The twins were facing in opposite directions with the left occipital region of one embryo fused with the left parietal-temporal region of the other. Additional multiplanar analysis above the level of the biparietal diameter demonstrated brain sharing.

Three-dimensional multiplanar transvaginal ultrasound of the cervix in pregnancy

OBJECTIVES

To develop a standard technique for using three-dimensional ultrasound (3D US) to study and evaluate the cervix in pregnant women at high risk for premature delivery, comparing the findings on 3D US with those on conventional two-dimensional ultrasound (2D US).

STUDY DESIGN

Twenty-one pregnant women at high risk for premature delivery had a total of 37 transvaginal 2D and 3D US examinations of the cervix between 11 and 32 weeks' gestation. A 3D US vaginal probe (5.0-8.0 MHz, Voluson 530D, Medison, Pleasanton, CA, USA) was used. Measurements made from the 2D and 3D US were compared.

RESULTS

Of the 37 cervical length measurements in 3D US sagittal plane, seven were shorter and three were longer than on 2D US (varying by 5-15 mm) indicating that the true mid-sagittal plane was not obtained in ten (27%) of the 37 2D US examinations. Of 21 examinations showing funneling, funneling was seen on both 2D and 3D US in 15, but was seen only on 3D US in six. There was a significant (P < 0.05) difference between funnel width as measured in the coronal 3D plane versus 2D US, as well as between funnel width in the coronal 3D US plane versus sagittal 3D US plane (P < 0.05). The cerclage was seen in its entirety in nine of 10 examinations; the 3D US axial plane was most valuable for imaging the cerclage.

CONCLUSIONS

3D US appears to offer a more complete assessment of the cervix than 2D US. Multiplanar correlation shows that the standard 2D US sagittal view may under- or over-estimate cervical length. Our preliminary data suggest that 3D US has the potential to improve our understanding of cervical morphology.

Metronidazole to prevent preterm delivery in pregnant women with asymptomatic bacterial vaginosis. National Institute of Child Health and Human Development Network of Maternal-Fetal Medicine Units

BACKGROUND

Bacterial vaginosis has been associated with preterm birth. In clinical trials, the treatment of bacterial vaginosis in pregnant women who previously had a preterm delivery reduced the risk of recurrence.

METHODS

To determine whether treating women in a general obstetrical population who have asymptomatic bacterial vaginosis (as diagnosed on the basis of vaginal Gram's staining and pH) prevents preterm delivery, we randomly assigned 1953 women who were 16 to less than 24 weeks pregnant to receive two 2-g doses of metronidazole or placebo. The diagnostic studies were repeated and a second treatment was administered to all the women at 24 to less than 30 weeks' gestation. The primary outcome was the rate of delivery before 37 weeks' gestation.

RESULTS

Bacterial vaginosis resolved in 657 of 845 women who had follow-up Gram's staining in the metronidazole group (77.8 percent) and 321 of 859 women in the placebo group (37.4 percent). Data on the time and characteristics of delivery were available for 953 women in the metronidazole group and 966 in the placebo group. Preterm delivery occurred in 116 women in the metronidazole group (12.2 percent) and 121 women in the placebo group (12.5 percent) (relative risk, 1.0; 95 percent confidence interval, 0.8 to 1.2). Treatment did not prevent preterm deliveries that resulted from spontaneous labor (5.1 percent in the metronidazole group vs. 5.7 percent in the placebo group) or spontaneous rupture of the membranes (4.2 percent vs. 3.7 percent), nor did it prevent delivery before 32 weeks (2.3 percent vs. 2.7 percent). Treatment with metronidazole did not reduce the occurrence of preterm labor, intraamniotic or postpartum infections, neonatal sepsis, or admission of the infant to the neonatal intensive care unit.

CONCLUSIONS

The treatment of asymptomatic bacterial vaginosis in pregnant women does not reduce the occurrence of preterm delivery or other adverse perinatal outcomes.

Posterior urethral valves: inaccuracy of prenatal diagnosis

This study was undertaken to determine the specificity of prenatal diagnosis of posterior urethral valves. Twenty-two fetuses were diagnosed in utero with posterior urethral valves due to the presence of persistent megacystis and hydronephrosis. Ten cases had oligohydramnios and 12 had normal or increased fluid. Confirmation of diagnosis was not available in 3 fetuses. Only 8 of 19 fetuses had postnatal confirmation of posterior urethral valves. Other anomalies included urethral atresia, ureteral duplication, megacystis/megaureter, reflux and multicystic dysplastic kidney. We conclude that in utero evidence of megacystis and hydronephrosis with or without oligohydramnios is not diagnostic of posterior urethral valves.

Three ethically justified indications for selective termination in multifetal pregnancy: a practical and comprehensive management strategy

The authors provide an ethical justification for three indications for performing selective termination of multi-fetal pregnancies. These indications are (1) achieving a pregnancy that results in a live birth or one or more infants with minimal neonatal morbidity and mortality, (2) achieving a pregnancy that results in a live birth of one or more infants without antenatally detected anomalies, and (3) achieving a pregnancy that results in a singleton live birth. This ethical justification is based on two basic approaches to obstetric ethics that emphasize that these indications must be established on the basis of informed consent. The authors underscore the importance of matters of private conscience and demonstrate the consistency of ethical justification with existing public policy in the United States.

Fetal hepatosplenomegaly associated with transient myeloproliferative disorder in trisomy 21

The in utero diagnosis of fetal myeloproliferative disease was made by cordocentesis following the ultrasound appearance of fetal hepatosplenomegaly and mild hydrops. The 2 fetuses reported both had leukocyte counts greater than 75,000/mm3 with a predominance of blast forms. In both cases the karyotype revealed trisomy 21.

Molecular analysis of the 18q- syndrome--and correlation with phenotype

Seven individuals with deletions of the distal long arm of chromosome 18 were evaluated at the clinical, cytogenetic, and molecular levels. The patients had varying degrees of typical clinical findings associated with the 18q- syndrome. Cytogenetic analysis revealed deletions from 18q21.3 or 18q22.2 to qter. Somatic cell hybrids derived from the patients were molecularly characterized using ordered groups of probes isolated from a chromosome 18-specific library. In general, the size of the deletion could be correlated with the severity of the phenotype. Based on the clinical pictures of these seven patients, a preliminary phenotypic map for the clinical features associated with deletions of the distal portion of the long arm has been generated. Furthermore, genes previously localized to 18q21 were mapped relative to the chromosome breakpoints present in these patients.

Diagnosis and prenatal diagnosis of epidermolysis bullosa herpetiformis (Dowling-Meara) in a mother, two affected children, and an affected fetus

In utero skin biopsy was performed on a fetus at risk of an uncertain form of epidermolysis bullosa (EB). The mother had produced two affected offspring diagnosed variously as having junctional or dystrophic EB. The two offspring and the fetus were products of different fathers. The mother claimed to have no disease and on clinical examination was without blisters. Examination of the fetal skin biopsy by light and electron microscopy revealed separation of the epidermal sheet from the majority of the biopsy sample, although occasional remnants of basal cells remained associated with the basement membrane. Aggregations of keratin filaments were observed within basal cells of the detached epidermis and in the attached basal cell remnants. The diagnosis was thus suggested to be epidermolysis bullosa Dowling-Meara. Re-review of the clinical and laboratory data from the affected infants revealed a clinical and histological pattern consistent with this diagnosis. Further discussion with the mother revealed that her skin had blistered as a child and that she presently had hyperkeratotic palms and soles. This history is consistent with the autosomal dominantly inherited epidermolysis bullosa herpetiformis (Dowling-Meara). This is the first reported prenatal diagnosis of EB Dowling-Meara. The morphological criteria of intraepidermal blistering and clumped keratin filaments within basal and immediately suprabasal cells characteristic of an affected individual postnatally also identified an affected fetus. There is, however, insufficient experience to be certain that these findings will hold from region to region in the body or among all affected fetuses, and thus prenatal diagnosis on a morphological basis should still be made with caution.

Risk factors associated with transcervical CVS losses

Factors found to be associated with pregnancy loss after transcervical CVS were race (higher for non-white), history of spontaneous abortion, unplanned pregnancy, history of spotting or bleeding during the pregnancy prior to CVS, and placental position (higher for fundal or lateral locations). Whether the increase in loss risk is due to the factor, per se, or the factor plus the CVS cannot be determined due to the lack of appropriate control data.

First-trimester maternal serum alpha-fetoprotein and chorionic gonadotropin in aneuploid pregnancies

First-trimester maternal serum alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG) levels were measured in samples from 29 women with cytogenetically abnormal pregnancies and 145 women with cytogenetically normal pregnancies matched for gestational age, race, and sample storage time. All patients had a risk of fetal aneuploidy greater than or equal to that of a mother 35 years of age. AFP was significantly lower in samples from pregnancies affected with trisomy 21 (0.67 MoM; p less than 0.05), while HCG values were no different from those of matched controls. Trisomies 13 and 18 could not be distinguished from matched controls by AFP. However, levels of HCG were significantly lower in such pregnancy samples, with median values of 0.65 MoM in trisomy 13 and 0.32 MoM in trisomy 18 (p less than 0.05). Variations in AFP and HCG levels suggest that expressed differences between autosomal aneuploidies include differences in fetal and placental protein production in the first trimester.

Very high CA 125 levels during early first trimester in three cases of spontaneous abortion with chromosomal abnormalities

Three women with very elevated, early-first-trimester CA 125 levels spontaneously aborted but not until later in the first trimester or early in the second trimester. All three products of conception showed chromosomal abnormalities. Further investigation is warranted to see if high CA 125 levels might be predictive of abnormal karyotypes.

Addiction in pregnancy: high risk intrapartum management and outcome

Drug-dependent women (DDW) have an increased incidence of medical and obstetrical complications; however, little information exists on the intrapartum course and management of these patients. Within the context of Family Center, a study was undertaken to determine if the DDW had normal patterns of labor and if standard intrapartum management is appropriate. The study population included 336 women of which 112 were DDW (72 per cent receiving methadone maintenance). The comparison group of 224 non drug dependent women was matched for gravidity, parity, and socioeconomic background. The incidence of premature delivery, abruptio placentae, breech presentation, and intrauterine growth retardation were significantly greater in the DDW. The average duration of the first, second, and third stages of labor compared well with the normal course of labor and matched the results of the comparison group. Labor abnormalities and cesarean sections were of no greater incidence, but there were more than twice as many forceps deliveries which coincides with the 40 per cent increased use of epidural anesthesia. Analgesia and anesthesia were in excess of that which is given to the average patient. There were three stillborns, one neonatal death, and one maternal death. Apgar scores and the incidence of fetal distress and meconium staining were identical in both groups. Postpartum complications were more common in the DDW, but most were secondary to the use of subclavian intravenous lines inserted due to the presence of sclerotic veins. These data suggest that high risk prenatal management and careful monitoring in the intra- and postpartum periods utilizing epidural anesthesia identifies and usually prevents untoward complications in DDW.

Pregnancy in a drug-abusing population

Substance abuse in pregnancy places both mother and infant at extremely high risk. There is little information, however, about the impact of changing patterns of drug use and improvements in medical technology on pregnancy outcome. The Family Center Program utilizes a team approach to provide counseling, support, and education as well as complete medical care for substance-abusing pregnant women. We reviewed the records of women seen in the Family Center Program from 1981 to 1983 to evaluate the effect of intervention on pregnancy outcome. Complications, including prematurity, growth retardation, intrauterine fetal demise, and neonatal abstinence, were common, although early prenatal care and frequent visits appear to reduce the risk of low birth weight infants. Uncorrected perinatal mortality was 11/163 (67/1,000). Compared to earlier experience in this program, few women delivered with no prenatal care. Thus a program designed specifically for the needs of these women is successful in increasing the number seeking prenatal care and appears to improve pregnancy outcome. Despite this, serious problems are common and further improvement seems unlikely unless such women can be maintained in a stable, drug-free environment during their pregnancies.

Subsequent reproductive outcome in couples with repeated pregnancy loss

While the role of cytogenetic study in couples with repeated pregnancy loss is well-established, little information is available for counseling these couples concerning future reproductive outcome. Couples evaluated by chromosome analysis for recurrent abortion between 1972 and 1979 were contacted by phone in 1981. Of those studied cytogenetically, 195 couples (50.1%) could be located, and information concerning outcome of subsequent pregnancies were obtained. Couples (91) with two consecutive pregnancy losses at the time of initial investigation had a 31.3% subsequent abortion rate, but most (68%) had at least one liveborn child. The rate of infertility following evaluation was slightly increased (18.7%), but that of prematurity (11.2%) and congenital anomalies (2.5%) was not. In contrast, couples with greater than or equal to 3 consecutive losses (84) experienced abortion in 45.7% of subsequent pregnancies, and only 54.8% of them eventually had a liveborn child. Again, the rate of infertility was increased (26.2%), but that of prematurity (10%) and congenital defects (3.2%) was not. Nine couples in which one individual was found to have a chromosome abnormality (two inversions and seven translocations) were considered separately. Of these, seven couples had nine liveborn offspring. Amniocentesis was performed in eight cases, with karyotypes showing a balanced translocation identical to that of the parent in 2. All children were phenotypically normal.