Quadruplet pregnancy outcome with and without fetal reduction: Danish national cohort study (2008-2018) and comparison with dichorionic twins.

OBJECTIVES: To perform a nationwide study of quadrichorionic quadriamniotic (QCQA) quadruplet pregnancies and to compare the pregnancy outcome in those undergoing fetal reduction with non-reduced quadruplets and dichorionic diamniotic (DCDA) twin pregnancies from the same time period. METHODS: This was a retrospective Danish national register-based study performed using data from the national Danish Fetal Medicine Database, which included all QCQA quadruplets and all non-reduced DCDA twin pregnancies with an estimated due date between 2008 and 2018. The primary outcome measure was a composite of adverse pregnancy outcomes, including pregnancy loss or intrauterine death of one or more fetuses. Secondary outcomes included gestational age at delivery, the number of liveborn children, preterm delivery before 28, 32 and 37 gestational weeks and birth weight. Data on pregnancy complications and baseline characteristics were also recorded. Outcomes were compared between reduced and non-reduced quadruplet pregnancies, and between DCDA pregnancies and quadruplet pregnancies reduced to twins. A systematic literature search was performed to describe and compare previous results with our findings. RESULTS: Included in the study were 33 QCQA quadruplet pregnancies, including three (9.1%) non-reduced pregnancies, 28 (84.8%) that were reduced to twin pregnancy and fewer than three (6.1%) that were reduced to singleton pregnancy, as well as 9563 DCDA twin pregnancies. Overall, the rate of adverse pregnancy outcome was highest in non-reduced quadruplets (66.7%); it was 50% in quadruplets reduced to singletons and 10.7% in quadruplets reduced to twins. The proportion of liveborn infants overall was 91.1% of the total number expected to be liveborn in quadruplet pregnancies reduced to twins. This was statistically significantly different from 97.6% in non-reduced dichorionic twins (P = 0.004), and considerably higher than 58.3% in non-reduced quadruplets. The rates of preterm delivery < 28, < 32 and < 37 weeks were decreased in quadruplets reduced to twins compared with those in non-reduced quadruplet pregnancies. Quadruplets reduced to twins did not achieve equivalent pregnancy outcomes to those of DCDA twins. CONCLUSION: This national study of QCQA quadruplets has shown that multifetal pregnancy reduction improves pregnancy outcome, including a decreased rate of preterm delivery and higher proportion of liveborn children. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Prevalence of chromosomal disorders in cases with congenital heart defect: registry-based study from Denmark between 2008 and 2018.

OBJECTIVE: To estimate the prevalence of chromosomal conditions in all fetuses and children with major congenital heart defect (CHD) in Denmark between 2008 and 2018. METHODS: This was a national registry-based study including all singleton pregnancies with a prenatally or postnatally diagnosed major CHD usually requiring surgery within the first year after birth and a due date between July 2008 and December 2018 in Denmark. Data were retrieved from the Danish Fetal Medicine Database (DFMD) and the Danish Cytogenetic Central Register (DCCR) in October 2020. The DCCR contains information on all prenatal and postnatal genetic analyses, including karyotyping, chromosomal microarray, polymerase chain reaction, multiplex ligation-dependent probe amplification and fluorescence in-situ hybridization. All cases were reviewed by a clinical geneticist, and genetic changes were classified as pathogenic, likely pathogenic, variant of uncertain significance, likely benign or benign. Pathogenic and likely pathogenic variants were considered to be abnormal. Cases with CHD without any registered chromosomal analysis reported were considered genetically normal. Isolated CHD was defined as a case with major CHD without any other structural malformations detected prenatally or postnatally. Results are given as n (%). Comparisons between isolated and non-isolated cases were performed using logistic regression analysis, and data are presented as odds ratios (ORs) with 95% CIs. RESULTS: A total of 8482 cases with any cardiovascular diagnosis were retrieved from the DFMD. Twins (n = 112) and minor CHD cases (n = 6921) were excluded, resulting in 1449 cases with major CHD. Of the included cases, 918 (63.4%) underwent chromosomal analysis. An abnormal test result was found in 187 cases, giving a prevalence of a chromosomal condition of 12.9% (95% CI, 11.2-14.7%) among all cases with major CHD. The highest prevalence of a chromosomal condition was found in cases with pulmonary atresia with intact ventricular septum and those with truncus arteriosus (both 28.6%), while the lowest prevalence was found in cases with transposition of the great arteries (2.2%) and congenitally corrected transposition of the great arteries (0%). In isolated cases of transposition of the great arteries, the prevalence of a chromosomal condition was 0.6%. The overall OR for a chromosomal condition in non-isolated cases compared with isolated cases was 2.72 (95% CI, 1.90-3.88). CONCLUSIONS: We found an overall prevalence of a chromosomal condition of 12.9% among cases with major CHD in a national cohort with a high participation rate in first- and second-trimester screening, without employing whole genome and whole exome sequencing. The prevalence of a chromosomal condition varied considerably according to CHD diagnosis and presence of associated extracardiac malformations. These findings are important for prenatal counseling. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Targeted gene sequencing and whole-exome sequencing in autopsied fetuses with prenatally diagnosed kidney anomalies.

Identification of fetal kidney anomalies invites questions about underlying causes and recurrence risk in future pregnancies. We therefore investigated the diagnostic yield of next-generation sequencing in fetuses with bilateral kidney anomalies and the correlation between disrupted genes and fetal phenotypes. Fetuses with bilateral kidney anomalies were screened using an in-house-designed kidney-gene panel. In families where candidate variants were not identified, whole-exome sequencing was performed. Genes uncovered by this analysis were added to our kidney panel. We identified likely deleterious variants in 11 of 56 (20%) families. The kidney-gene analysis revealed likely deleterious variants in known kidney developmental genes in 6 fetuses and TMEM67 variants in 2 unrelated fetuses. Kidney histology was similar in the latter 2 fetuses-presenting a distinct prenatal form of nephronophthisis. Exome sequencing identified ROBO1 variants in one family and a GREB1L variant in another family. GREB1L and ROBO1 were added to our kidney-gene panel and additional variants were identified. Next-generation sequencing substantially contributes to identifying causes of fetal kidney anomalies. Genetic causes may be supported by histological examination of the kidneys. This is the first time that SLIT-ROBO signaling is implicated in human bilateral kidney agenesis.