Maternal Serum Screening Results Research Articles

Fetal genetic findings by chromosomal microarray analysis and karyotyping for fetal growth restriction without structural malformations at a territory referral center: 10-year experience

BackgroundPrenatal invasive genetic testing is commonly recommended to pregnancies of early-onset FGR or FGR combined with a structural defect. Our study aimed to explore the genetic findings for FGR without structural malformations according to cytogenetic karyotyping and single nucleotide polymorphism array (SNP array) technology over a 10-year period.MethodsA total of 488 pregnancies diagnosed with FGR without structural malformation were retrospectively reviewed. Cytogenetic karyotyping was performed on all the subjects, and SNP array was available from 272 of them. Based on the gestational age at onset, the cohort was classified into four groups: ≤ 24, 25–28, 29–32, and > 32 weeks of gestation. According to the ultrasound findings, they were grouped into isolated FGR, FGR with soft markers, and FGR with non-structural anomalies. In pregnancies of young maternal age, based on the results of maternal serum screening (MSS), they were categorized into high-risk and low-risk MSS groups.ResultsNineteen (3.9%) cases of chromosomal abnormalities were detected by cytogenetic karyotyping, including 11 cases of numerical abnormalities, 5 cases of structural abnormalities, and 3 cases of mosaicism. Trisomy 21 was the most frequent abnormality. Abnormal karyotypes were more frequently observed in cases diagnosed at ≤ 24 weeks (7.2%) than those in any other group. Among pregnancies with normal karyotype, an incremental yield of 4.2% were revealed by SNP array technology regarding clinically relevant aberrations. The additional detection rates by SNP array in cases diagnosed at ≤ 24 weeks (6.5%), cases with soft markers (9.5%), and cases with high-risk MSS (12.0%) were higher than those in other groups within each classification. All the cases with abnormal karyotypes and 7 out of 11 pregnancies with clinically relevant anomalies revealed by SNP array alone resulted in pregnancy terminations.ConclusionChromosome abnormality is an important etiology for FGR with no associated structural malformations, and plays a crucial role in pregnancies decision-making. SNP array improves the detection of genetic anomalies especially in FGR diagnosed at ≤ 24 weeks, FGR combined with soft makers, and FGR combined with high-risk MSS.

Chromosomal Microarray Analysis Compared With Noninvasive Prenatal Testing in Pregnancies With Abnormal Maternal Serum Screening

OBJECTIVE: To examine the effect of maternal age on the rate of clinically significant chromosomal microarray analysis results in pregnancies with abnormal maternal serum screening and to establish the residual risk for abnormal microarray findings after omitting noninvasive prenatal testing (NIPT)–detectable aberrations in pregnancies with abnormal maternal serum screening. METHODS: This retrospective study included all chromosomal microarray analysis tests performed in pregnancies with abnormal maternal serum screening and normal ultrasonogram results over the years 2013–2021. The rate of clinically significant (pathogenic and likely pathogenic) chromosomal microarray analysis findings was compared with a local control cohort of 7,235 pregnancies with normal maternal serum screening and ultrasonogram results, stratified by maternal age. Calculation of residual risk for clinically significant chromosomal microarray analysis results after normal NIPT was performed by omission of common NIPT-detectable anomalies. Systematic review for studies examining the yield of chromosomal microarray analysis in pregnancies with abnormal maternal serum screening was performed from inception to October 2021, with no time or language restrictions. RESULTS: Of the 559 amniocenteses performed due to abnormal maternal serum screening, 21 (3.8%; 95% CI 2.4–5.7%) clinically significant chromosomal microarray analysis results were found. The residual risk for chromosomal microarray analysis aberrations after theoretically normal NIPT was estimated to be 2.0% (95% CI 1.1–3.6%) (1/50) and was significantly higher for women younger than age 35 years with abnormal maternal serum screening, compared with women with low-risk pregnancies. Systematic review yielded six articles encompassing 4,890 chromosomal microarray analysis results in pregnancies with abnormal maternal serum screening, demonstrating 2.3% residual risk for chromosomal microarray analysis anomalies after theoretically normal NIPT. DISCUSSION: Clinically significant chromosomal microarray analysis findings can be found in 1 of every 50 pregnancies with high-risk maternal serum screening after theoretically normal NIPT, implying that invasive testing and not NIPT should be recommended in such pregnancies. In addition, NIPT use as a first-tier screening modality instead of maternal serum screening would miss pregnancies at increased risk not only for common autosomal trisomies but for additional chromosomal microarray analysis–detectable disorders.

Trends of fetal chromosome analysis by amniocentesis before and after beginning of noninvasive prenatal testing: A single-center experience in Japan.

This study is to investigate the role of amniocentesis for prenatal diagnosis before and after the beginning of noninvasive prenatal testing (NIPT) in Japan. We performed a retrospective analysis of genetic amniocentesis at mid-trimester (15-20 gestational weeks) for fetal karyotype analysis at Nagoya City University between April 2006 and March 2020. The indications, test results, and the detection rate of fetal abnormal karyotype were compared before (phase 1, P1) and after (phase 2, P2) beginning of NIPT at April 2013. A total of 2458 (P1: 1132, P2: 1326) amniocentesis were enrolled in this study. The most frequent indication was advanced maternal age in both phases (P1: 78.2% %, P2: 81.1%). In P2, 110 patients (8.3%) received amniocentesis after positive or nonreportable NIPT results. Other indications were fetal abnormal findings by ultrasounds (P1: 15.4%, P2: 17.7%), abnormal maternal serum screening results (P1: 8.0%, P2: 10%), previous child with fetal chromosome aberration (P1: 6.5%, P2: 3.5%), and translocation of either partner (P1:1.5%, P2: 2.1%). The detection rate for fetal chromosomal aberrations including all indications was significantly increased in P2 (15.9%, 95% CI 14.0-18.0) as compared to P1 (9.0%, 7.4-10.8). However, if the indication was only advanced maternal age, the positive detection rate kept low in both phases (P1: 5.2%, 3.7-7.1, P2: 4.2%, 2.9-5.9). Since the initiation of NIPT, the detection rate of fetal chromosomal abnormalities was higher in this study, suggesting that amniocentesis cannot be strongly recommended for advanced maternal age alone.

Factors associated with test failure in pregnant women undergoing cell-free DNA-based testing for fetal trisomy.

To investigate the factors associated with cell-free DNA test failure, and the optimal subsequent management of these pregnancies. This was a retrospective study of 27,363 singleton pregnancies undergoing cell-free DNA testing. Women with cell-free DNA test failure were divided into a high-risk group and a low-risk group according to their indications. The subsequent management and pregnancy outcomes of these women were followed up. The rate of cell-free DNA test failure at the first sampling was 1.49%, and 78.4% of failures were due to a low fetal fraction. Of the 66 women who refused any subsequent management, an adverse pregnancy outcome was seen in 5 cases, all belonging to the high-risk group. Of the 13 low-risk women who chose second-trimester maternal serum screening, all obtained a low-risk maternal serum screening result and an unaffected pregnancy outcome. A redraw was chosen by 171 women, which yielded a result in 75.4% and their pregnancy outcomes were unaffected; 42 women had an uninformative result again and received an amniocentesis. As 158 women had an amniocentesis after the first sampling, this procedure was offered in 200 cases altogether. Abnormal genetic testing results were shown in six (3%, 6/200) cases, all in the high-risk group. High-risk pregnant women with cell-free DNA test failure are at increased risk of adverse pregnancy outcomes. A second sampling for cell-free DNA test or maternal serum screening might be suggested to low-risk women. Invasive prenatal diagnosis should be offered to the high-risk patients, especially those with a second cell-free DNA test failure.

Frequency and clinical manifestation of prenatal cytogenetic diagnosis of chromosomal polymorphisms in Northeast China

ObjectiveTo retrospectively analyze the incidence of chromosomal polymorphisms in prenatal cytogenetic diagnostic cases and the effect of the clinical manifestation of these fetuses. Materials and methods490 fetuses with chromosomal polymorphisms among 9996 pregnant women who underwent prenatal cytogenetic diagnosis were included in this study and were set as group 1. Other 500 pregnant women, whose fetuses were with normal karyotypes, were randomly selected from the remaining pregnant women and set as group 2. Clinical information and outcomes and maternal serum screening results of group 1 were compared with group 2. ResultsThe frequency of fetal chromosomal polymorphism was 4.90% (490/9996). The most common variants observed were 1/9/16 qh± (2.27%, 227/9996), followed by inv(9) (0.90%, 90/9996). 94.62% (264/279) of fetal chromosomal variants were inherited from parents. No statistical difference was found in clinical information and outcomes and maternal serum screening results between group 1 and group 2. ConclusionThe fetus with chromosomal polymorphism has no impact on serum markers of second trimester screening and does not play an important role for the clinical outcome of the current pregnancy either, whether it is inherited from the parents or a de novo mutation.

Is Noninvasive Prenatal Screening Appropriate for Pregnant Women Age 35 or Older In Cases if Isolated Fetal Nasal Bone Abnormalities in The Chinese Han Population?

BackgroundEthnic background may affect the prevalence of nasal bone absence and the length of the nasal bone. This study aimed to elucidate the significance of absent or hypoplastic fetal nasal bone in the Chinese Han population and to formulate an optimal management plan for patients age 35 or older in cases of isolated abnormal fetal nasal bone.Material/MethodsWe prospectively assigned pregnant women whose fetuses had nasal bone absence or hypoplasia to separate groups according to their choice for noninvasive prenatal screening (NIPS) between January 1, 2013, and December 31, 2018. Demographic data, ultrasound findings, results of conventional maternal serum screening and NIPS, fetal karyotype, pregnancy outcomes, and expenses associated with prenatal testing were recorded. The incidence and odds ratio of nasal bone abnormality and the sensitivity and specificity of different prenatal genetic screening tests were calculated.ResultsA total of 1946 cases with fetal nasal bone absence or hypoplasia were included. Cases of isolated nasal bone abnormality (1736 cases) were divided into the NIPS group (Gr 1, n=429) and the non-NIPS group (Gr 2, n=1307). Sixty-four cases involved chromosomal abnormality. The sensitivity, specificity, and positive and negative predictive values of NIPS in Gr 1 were 100%, 100%, 100%, and 100%, respectively. The odds ratio of fetal chromosomal abnormalities for isolated fetal nasal bone abnormalities when maternal age was ≥35 was 4.615 (95% CI: 1.592–13.381). The cost-effectiveness ratio of contingent screening (NIPS first) was significantly lower than amniocentesis directly.ConclusionsThe nasal bone provides an important marker for chromosome abnormalities in some populations, but to a lesser extent in the Chinese Han population. NIPS is an excellent first option for follow-up among pregnant women age ≥35 in cases of absent or hypoplastic fetal nasal bone in the first trimester ultrasound scan.

Death of a Fetus With Myeloproliferative Disorder and Trisomy 21

A 27-year-old woman, gravida 2, para 1, presented at 24 weeks gestation with an intrauterine death. She previously consulted with maternal-fetal medicine because of a high suspicion of trisomy 21 after abnormal maternal serum screen and cell-free DNA test results. The patient elected to have chromosomal analysis following the death of the fetus, which confirmed a trisomy 21 diagnosis. Placental pathologic findings suggested that the cause of fetal death was total occlusion of the major vessels due to the accumulation of myeloid precursor cells, a novel mechanism. This case report discusses the rare finding of myeloproliferative disorder as a cause of death of a fetus with trisomy 21.

Higher male prevalence of chromosomal mosaicism detected by amniocentesis

ObjectiveTo present the calculated frequencies, male to female sex-ratio, and modes of ascertainments in different levels of chromosomal mosaicism (CM) detected at amniocentesis. Materials and methodsThis's a 10-years retrospective study between January 2008 and December 2017 and there were 13,752 cases of amniocentesis performed in MacKay Memorial Hospital, Taipei, Taiwan. Eight hundred and thirty four cases of CM were collected in this study. We reviewed their types of chromosomal abnormalities of mosaicism, the modes of ascertainment (including: advanced maternal age, abnormal ultrasound findings, abnormal maternal serum screening result, and other reasons), maternal age, gestational age at amniocentesis, fetal gender, and perinatal findings. After amniocentesis, in situ culture was performed and the results of karyotype with CM were divided in to three levels. ResultsIn our sample of 13,752 amniocentesis, 834 cases with all levels of CM were collected in this study. Of them, there were 562 cases (4.09%) with level I mosaicism, 207 cases (1.51%) of level II mosaicism, and 65 cases (0.47%) of level III mosaicism (Table 1). In the group of advanced of maternal age (AMA), their calculated frequencies, 4.18% in level I, 1.46% in level II and 0.41% in level III, were very similar to those in total cases (p value = 0.206) without statistical significance. In the group of abnormal ultrasound findings, the calculated frequency was much higher in level III (0.87%), however, there was no statistical significance because of the small numbers of level III.In our cases of amniocentesis, the case numbers of male case (50.20%) is very similar to female (49.80%), and the male to female ratio was 1.01. But, we found more cases of male with CM (444 cases) than female (390 cases). The sex-ratio in different levels’ calculated frequencies of CM showed similar in level I, and male prevalence was found in level II and III with statistical significance (p value = 0.022). The male prevalence also revealed in both numerical and structural abnormalities in level II and level III, but no difference in the cases of level I. ConclusionIn conclusion, our observation showed a novel finding of higher male prevalence of CM in level II and III, and both in numerical and structural abnormalities. It's consistent with the theory of better survival in male embryo after partial self-correction of initial chromosomal aberrations, male-specific selection against chromosomal abnormalities.

Familial transmission of recurrent 15q11.2 (BP1-BP2) microdeletion encompassing NIPA1, NIPA2, CYFIP1, and TUBGCP5 associated with phenotypic variability in developmental, speech, and motor delay

ObjectiveWe present recurrent 15q11.2 (BP1-BP2) microdeletion encompassing NIPA1, NIPA2, CYFIP1, and TUBGCP5 in a family with phenotypic variability in developmental, speech, and motor delay. Case ReportA 32-year-old woman underwent amniocentesis at 17 weeks of gestation because of an abnormal maternal serum screening result of Down syndrome risk of 1/226. Her husband was 31 years old. She and her husband were phenotypically normal, and there was no family history of mental disorders and congenital malformations. Amniocentesis revealed a karyotype of 46,XX. Prenatal ultrasound findings were unremarkable. A 2492-g female baby was delivered at 37 weeks of gestation uneventfully. During the subsequent pregnancy, the same woman at the age of 35 years underwent amniocentesis at 18 weeks of gestation because of advanced maternal age, which revealed a karyotype of 46,XY. Prenatal ultrasound findings were unremarkable. A 2780-g male baby was delivered at 37 weeks of gestation uneventfully. About 3 years after the birth of this boy, array comparative genomic hybridization of the family revealed 15q11.2 microdeletion encompassing NIPA1, NIPA2, CYFIP1, and TUBGCP5 in the two siblings, who displayed developmental, speech, and motor delay, and in their phenotypically normal father. ConclusionRecurrent phenotypic abnormality in the family with normal karyotype at amniocentesis should include a differential diagnosis of familial pathogenic copy-number variations.

Molecular cytogenetic characterization of Xp22.32→pter deletion and Xq26.3→qter duplication in a male fetus associated with 46,Y,rec(X)dup(Xq) inv(X)(p22.3q26.3), a hypoplastic left heart, short stature, and maternal X chromosome pericentric inversion

ObjectiveWe present molecular cytogenetic characterization of an Xp22.32→pter deletion and an Xq26.3→qter duplication in a male fetus with congenital malformations and maternal X chromosome pericentric inversion. Materials and MethodsA 22-year-old woman underwent amniocentesis at 17 weeks of gestation because of an abnormal maternal serum screening result. Prenatal ultrasound revealed a hypoplastic left heart and short limbs. Amniocentesis revealed a karyotype of 46,Y,der(X) t(X;?)(p22.31;?). The pregnancy was subsequently terminated, and a malformed fetus was delivered with short stature and facial dysmorphism. Repeat amniocentesis was performed before termination of the pregnancy. Array comparative genomic hybridization was performed on uncultured amniocytes and maternal blood. Conventional cytogenetic analysis was performed on cultured amniocytes, cord blood, and blood from both parents. Fluorescence in situ hybridization was performed on cultured amniocytes. ResultsThe maternal karyotype was 46,X,inv(X)(p22.3q26.3). The fetal karyotype was 46,Y, rec(X)dup(Xq)inv(X)(p22.3q26.3) or 46,Y, rec(X)(qter→q26.3::p22.3→qter). Array comparative genomic hybridization on uncultured amniocytes revealed a 4.56-Mb deletion of Xp22.33–p22.32 encompassing SHOX, CSF2RA, and ARSE, and a 19.22-Mb duplication of Xq26.3–q28 encompassing SOX3, FMR1, MECP2, RAB39B, and CLIC2 in the fetus. The mother did not have X chromosome imbalance. ConclusionDetection of X chromosome aberration in a male fetus should give suspicion of a recombinant X chromosome derived from maternal X chromosome pericentric inversion.

Genetic amniocentesis results: analysis of the 3721 cases

Genetic amniocentesis results: analysis of the 3721 cases Objective: To retrospectively investigate the 7-year experience of prenatal diagnosis of fetal chromosome aberrations by second-trimester genetic amniocentesis. Material and Method: Data were collected at Meram Medical Faculty Obstetric and Gynecology Department between January 2007 and January 2014 from cytogenetic analyses of cultured amniocytes from second-trimester amniocentesis. The main indications for amniocentesis included advanced maternal age, abnormal maternal serum screening results, and abnormal ultrasound findings. Chromosome aberrations included autosomal aneuploidies, sex chromosome aneuploidies, polyploidies, and rearrangements. Results: A total of 3702 amniocenteses were performed and analyzed for chromosome aberrations. Among these, 1677 (45.1%) were for abnormal maternal serum screening results, 1332 (35.8%) for advanced maternal age, 586 (15.8%) for abnormal ultrasound findings, and 126 (3.3%) for other reasons. Chromosome aberrations were detected in 131 (3.6%) cases, including fetuses of 53 older mothers, 37 mothers with abnormal serum screening results, 34 mothers with abnormal ultrasound findings, and 7 mothers with other reasons for amniocentesis. Of fetuses with chromosome aberrations, 106 (80.9%) had numerical chromosomal disorder. The other 25 (19.1%) cases included

Pregnancy with de novo 9q34.3 microdeletion and Kleefstra syndrome in the fetus may be associated with an abnormal maternal serum screening result

Pregnancy with de novo 9q34.3 microdeletion and Kleefstra syndrome in the fetus may be associated with an abnormal maternal serum screening result

A case of complete tetraploidy in amniocentesis with normal karyotype in subsequent cordocentesis.

We report a case of complete tetraploidy in amniotic fluid culture obtained at 17 wk of pregnancy. Amniocentesis was performed in this pregnancy because of a high-risk maternal serum screening result and abnormal ultrasound findings. Amniotic fluid was cultured in two flasks. Growth was very slow in one culture with no growth in the other. Harvest was possible after 3 wk, which revealed tetraploidy in all studied plates. Subsequent cordocentesis was performed to confirm the diagnoses of amniocentesis. Chromosomal analysis of the cordocentesis revealed a normal karyotype with 46,XY. A healthy male infant was born at term. This case illustrates that abnormal karyotypes in poor growth cultures could be misleading and should be confirmed by another technique, such as cordocentesis.

Chromosome abnormalities diagnosed in utero: a Japanese study of 28 983 amniotic fluid specimens collected before 22 weeks gestations.

To investigate the frequency and type of abnormal karyotype in Japan by amniocentesis before 22 weeks of gestation. We performed a retrospective analysis of 28 983 amniotic fluid specimens in a local population collected before 22 weeks gestations for fetal karyotyping. The incidence of abnormal karyotype was 6.0%. The main indication was advanced maternal age (AMA) of 35 years and older, which represented over half of the clinical indications. Abnormal karyotype was most frequently reported among the referrals for abnormal ultrasound findings (21.8%), followed by positive maternal serum screen results (5.3%). Three-fourths of abnormal karyotype was either autosomal aneuploidy (64.0%) or sex chromosome aneuploidy (11.6%). Abnormal karyotype was detected in 2.8% of pregnant women referred for AMA. Clinically significant abnormal karyotype increased with advancing maternal age. The frequency and type of abnormal karyotype detected by amniocentesis for various indications were determined. Amniocentesis was mainly performed among the referrals for AMA, which is a characteristic distribution of indications of Japan.

Cytogenetic analysis of 6,142 amniocentesis cases: A 6-year single centre experience

The aim of our study was to evaluate the incidences and chromosomal abnormality detection rates of various indications for genetic amniocentesis. We retrospectively analysed 6,142 amniocentesis cases performed in a single centre between January 2007 and April 2013. We assessed the indications for prenatal diagnosis, fetal karyotypes, maternal ages, fetal ultrasound findings and maternal serum screening results. The most common indication for genetic amniocentesis was an abnormal maternal serum-screening test (36.6%), followed by advanced maternal age (28%), advanced maternal age and an abnormal maternal serum screening test (14.9%) and abnormal ultrasound findings (11.2%). The highest positive predictive values obtained from the indications included abnormal ultrasound findings and abnormal maternal serum screening test (12.9%) and advanced maternal age (12.2%). Although advanced maternal age and abnormal maternal serum screening tests were the most common indicators, their association with abnormal ultrasound findings should be identified to increase the efficacy of genetic amniocentesis.

Prenatal diagnosis and molecular cytogenetic characterization of a de novo pure distal 9p deletion and literature review

We present rapid aneuploidy diagnosis of distal 9p deletion by array comparative genomic hybridization using uncultured amniocytes in a pregnancy associated with an abnormal maternal serum screening result and intrauterine growth restriction (IUGR) in the fetus. We review the literature of prenatal diagnosis of distal 9p deletion, and add abnormal maternal serum biochemistry and fetal IUGR in the distinctive prenatal findings in pregnancy with fetal distal 9p deletion. We discuss the consequence of haploinsufficiency of DOCK8, KANK1, VLDLR and DMRT1 in this case.

Prenatal diagnosis and molecular cytogenetic characterization of a de novo interstitial deletion of 7q (7q22.1 → q31.1)

We present prenatal diagnosis and molecular cytogenetic characterization of de novo interstitial deletion of 7q (7q22.1→q31.1) by aCGH, FISH and QF-PCR in a fetus with an abnormal maternal serum screening result and ultrasound findings of facial cleft and hypogenitalism. We discuss the genotype–phenotype correlation and the consequence of haploinsufficiency of ZKSCAN5, ARPC1A, CYP3A43, RELN, LAMB1, IMMP2L and DOCK4 in this case.

Prenatal diagnosis and molecular cytogenetic characterization of a derivative chromosome der(18;18)(q10;q10)del(18)(q11.1q12.1)del(18)(q22.1q22.3) presenting as apparent isochromosome 18q in a fetus with holoprosencephaly

Objective To present prenatal diagnosis and molecular cytogenetic characterization of a derivative chromosome der(18;18)(q10;q10)del(18)(q11.1q12.1)del(18)(q22.1q22.3). Materials, Methods, and Results A 32-year-old woman was referred for genetic counseling of prenatally detected isochromosome 18q [i(18q)]. She had undergone amniocentesis at 19 gestational weeks because of a trisomy 18 risk of 1/39 derived from abnormally low levels of maternal serum unconjugated estriol, inhibin A, α-fetoprotein, and total β-human chorionic gonadotropin. Amniocentesis revealed a karyotype of 46,XX,i(18)(q10). Parental karyotypes were normal. Prenatal ultrasound showed alobar holoprosencephaly. Repeated amniocentesis was requested and performed at 21 gestational weeks. Array-comparative genomic hybridization analyses revealed a 14-Mb deletion of 18p11.32-p11.21, a 37.8-Mb duplication of 18q12.1-q22.1, and a 6.9-Mb duplication of 18q22.3-q23. Metaphase fluorescence in situ hybridization study showed the absence of an 18q12.1-specific probe signal in one arm and the absence of an 18q22.2-specific probe signal in the other arm of the derivative chromosome. Quantitative fluorescent polymerase chain reaction analysis determined a paternal origin of the derivative chromosome. The cytogenetic result was 46,XX,der(18;18)(q10;q10)del(18)(q11.1q12.1)del(18)(q22.1q22.3). The fetus postnatally manifested cebocephaly. Conclusion Concomitant monosomy 18p and trisomy 18q can be associated with holoprosencephaly and abnormal maternal serum screening results. Array-comparative genomic hybridization, fluorescence in situ hybridization, and quantitative fluorescent polymerase chain reaction are useful in genetic counseling of prenatally detected isochromosomes by providing information on the origin and genetic components of the isochromosome.

Unbalanced reciprocal translocations at amniocentesis

Objective To present perinatal findings, modes of ascertainments, and modes of segregation in unbalanced reciprocal translocations detected at amniocentesis. Materials and Methods Between January 1987 and July 2010, 40 cases with unbalanced reciprocal translocations were diagnosed by amniocentesis at Mackay Memorial Hospital, Taipei, Taiwan. The 40 cases originated from 29 families; 21 families with one case, 7 families with two cases, and 1 family with five cases. Results Of 40 cases, 33 (82.5%) presented fetal ultrasound abnormalities and 7 (17.5%) presented no ultrasound abnormalities. Of 40 cases, 36 (90%) had a segregation mode of adjacent-1 2:2 segregation, 3 (7.5%) had a segregation mode of 3:1 segregation with tertiary trisomy, and 1 (2.5%) had a segregation mode of 3:1 segregation with tertiary monosomy. Of 29 families, 7 (24.1%) had de novo translocations and 22 (75.9%) had inherited translocations. In seven de novo cases, the main modes of ascertainments included abnormal ultrasound findings ( n = 5) and advanced maternal age ( n = 2). In 22 inherited families, the main modes of first ascertainment included abnormal ultrasound findings ( n = 8), a previous aneuploid child ( n = 8), advanced maternal age ( n = 4), parental carrier status ( n = 1), and abnormal maternal serum screening results ( n = 1). Among 22 inherited families, 9 (40.9%) had a known parental carrier status, but 13 (59.1%) were unaware of parental carrier status at amniocentesis. Conclusion Unbalanced reciprocal translocations detected at amniocentesis are frequently associated with abnormal ultrasound findings. Prenatal diagnosis of an unbalanced translocation may incidentally detect a balanced translocation in the family. Prenatal diagnosis of fetal structural abnormalities should alert structural chromosome rearrangements and prompt cytogenetic analysis of the fetus and parents if necessary.

Sonographic Maturation of the Placenta at 30 to 34 Weeks Is Not Associated With Second Trimester Markers of Placental Insufficiency in Low-risk Pregnancies

ObjectiveAdvanced placental maturation (Grannum [G] grade 3) before term is associated with adverse perinatal outcomes associated with placental insufficiency. The nature and timing of the underlying pathology of this process is presently unclear. We hypothesized that advanced placental maturation at 30 to 34 weeks’ gestation is not associated with established second trimester markers of severe placental dysfunction. MethodsIn a cohort study of 1238 low-risk Caucasian women with singleton pregnancies who had sonographic assessment of placental maturation and fetal growth at 34 weeks, the results of maternal serum screening (MSS) and uterine artery Doppler (UtAD) flow studies at 16 weeks were related to adverse perinatal outcomes associated with placental insufficiency: antepartum hemorrhage, preeclampsia, preterm birth < 37 weeks, small for gestational age (<10th percentile), or postnatal evidence of intrauterine growth restriction (IUGR; ponderal index < 5th percentile). ResultsG1 was found in 127 women (10.3%), G2 was found in 18 women (1.5%), and no cases of G3 were observed. Advanced Grannum grading was significantly associated with IUGR (48 [4.4%] in G0, 9 [7.1%] in G1, 5 [27.8%] in G2; P < 0.001), but was dependent on smoking status. IUGR was not predicted by abnormal MSS or abnormal UtAD findings at either the second or third trimester ultrasounds. ConclusionG2 maturation at 30 to 34 weeks’ gestation is associated with mild IUGR at delivery in low-risk women and with smoking. IUGR was not predicted by either second or third trimester markers of severe placental dysfunction. Future studies directly observing the placenta in the late third trimester may aid the elusive diagnosis of “late-onset” mild IUGR.