The Effect of Vanishing Twin on Firstand Second-Trimester Maternal Serum Markers and Nuchal Translucency: A Multicenter Prospective Cohort Study

Background@#The purpose of this study was to evaluate the effect of vanishing twin (VT) on maternal serum marker concentrations and nuchal translucency (NT). @*Methods@#This is a secondary analysis of a multicenter prospective cohort study in 12 institutions. Serum concentrations of pregnancy-associated plasma protein-A in the first trimester and alpha-fetoprotein (AFP), total human chorionic gonadotrophin, unconjugated estriol, and inhibin A in the second trimester were measured, and NT was measured between 10 and 14 weeks of gestation. @*Results@#Among 6,793 pregnant women, 5,381 women were measured for serum markers in the first or second trimester, including 65 cases in the VT group and 5,316 cases in the normal singleton group. The cases in the VT group had a higher median multiple of the median value of AFP and inhibin A than the normal singleton group. The values of other serum markers and NT were not different between the two groups. After the permutation test with adjustment,AFP and inhibin A remained significant differences. The frequency of abnormally increased AFP was also higher in the VT group than in the normal singleton group. @*Conclusion@#VT can be considered as an adjustment factor for risk assessment in the secondtrimester serum screening test.

Validation of a Strict Obesity Definition Proposed for Asians to Predict Adverse Pregnancy Outcomes in Korean Pregnant Women

Background@#People are generally considered overweight and obese if their body mass index (BMI) is above 25 kg/m 2 and 30.0 kg/m 2 , respectively. The World Health Organization proposed stricter criteria for Asians (≥ 23 kg/m2 : overweight, ≥ 25 kg/m2 : obese). We aimed to verify whether this criteria could predict adverse pregnancy outcomes in Korean women. @*Methods@#We included 7,547 Korean women from 12 institutions enrolled between June 2016 and October 2018. Women with no pre-pregnancy BMI data, not Korean, or lost to followup were excluded, leaving 6,331. The subjects were categorized into underweight, normal, overweight, class I obesity, and class II/III obesity based on a pre-pregnancy BMI of < 18.5, 18.5–22.9, 23.0–24.9, 25.0–29.9, and ≥ 30.0 kg/m2 , respectively. @*Results@#Overall, 13.4%, 63.0%, 11.8%, 9.1%, and 2.6% of women were underweight, normal, and overweight and had class I obesity and class II/III obesity, respectively. In the multivariable analysis adjusted for maternal age, a higher BMI significantly increased the risk of preeclampsia, gestational diabetes, preterm delivery caused by maternal-fetal indications, cesarean section, large for gestational age, and neonatal intensive care unit admission. @*Conclusion@#Adverse pregnancy outcomes started to increase in those with a pre-pregnancy BMI ≥ 23.0 kg/m2 after adjusting for maternal age. The modified obesity criteria could help predict adverse pregnancy outcomes in Koreans.

Insight into the pathogensis of polycystic ovarian syndrome

Polycystic ovarian syndrome (PCOS) is the most common endocrine disorder in women, which is characterized by the oligo/ anovulation, hyperandrogenism (HA) and polycystic ovarian morphology which are diagnostic criteria. PCOS has diverse clinical aspects in addition to those diagnostic criteria including increased risk for cardiovascular diseases, metabolic syndrome, dyslipidemia, type 2 diabetes and impaired fertility. Because of the heterogeneity of the disease, the pathogenesis of the disease has not been elucidated yet. Therefore, there is no cure for the endocrinopathy. HA and insulin resistance (IR) has been considered two major pillars of the pathogenesis of PCOS. Recent advances in animal studies revealed the critical role of neuroendocrine abnormalities in developing PCOS. Several pathways related to neuroendocrine origin have been investigated such as hypothalamus pituitary ovarian axis, hypothalamus pituitary adrenal axis and hypothalamus pituitary adipose axis. This review summarizes the current knowledge about the role of HA and IR in developing PCOS. In addition, we review the results of recent genome wide association studies for PCOS. This new perspective improves our understanding of the role of neuroendocrine origins in PCOS and suggest a novel potential therapeutic target for the treatment of PCOS.

Experiences and efficacy of noninvasive prenatal test using maternal plasma in single center: 1,591 cases

Purpose@#The objective of this study was to analyze the results of several noninvasive prenatal tests (NIPTs) from a single center and confirm their efficacy and reliability. In addition, we aimed to confirm the changes in the number of invasive tests performed after introducing NIPT. @*Materials and Methods@#NIPT data from a large single center from March 2014 to November 2018 were analyzed. Karyotyping was confirmed based on chorionic villus sampling, amniocentesis, or postnatal cord/peripheral blood sampling. Data on maternal age, gestational age, fetal fraction, and ultrasonographic results were analyzed. As the secondary outcome, the number of amniocentesis cases before and after the introduction of NIPT was compared. @*Results@#Overall, 1,591 single pregnancy cases that underwent NIPT were enrolled. The mean maternal age was 36.05 (22-45) years. The average gestational age and fetal fraction were 12+1 (9+3 to 27+1) weeks and 10.95% (3.6% to 31.3%), respectively. A total of 1,544 cases (97.0%) were reported to have negative NIPT results and 40 (2.5%) had positive NIPT results. The sensitivity and specificity of the overall abnormalities in NIPT were 96.29% and 99.36%, respectively. The positive predictive value (PPV) and negative predictive value were 72.22% and 99.93% respectively. The mean number of amniocentesis cases were 21.7 per month (21.7±3.9), which significantly decreased from 31.5 per month (31.5±4.8) before conducting NIPT as a screening test. @*Conclusion@#NIPT is currently a useful, powerful, and safe screening test. In particular, trisomy 21 is highly specific due to its high PPV. NIPT can reduce the potential risks of procedure-related miscarriages during invasive testing.

Medical Issues and Opinions of Obstetrics Regarding Abortion Law Amendment

There have been ongoing social discussions on revision of the abortion law since the Constitutional Court ruled it nonconformity to the constitution on April 11, 2019. Thus, Korean Society of Obstetrics and Gynecology, Korean Society of Maternal Fetal Medicine, Korean College of Obstetricians and Gynecologists, and Korean Association of Obstetricians and Gynecologists organized 'special committee for abortion law' to support social discussion on the revision of the abortion law, and they prepared official opinions of obstetrics for medical issues including doctors' right to refuse abortion. In the future, the committee will continue to adapt to changes of medical environment especially after the revision of the abortion law by collecting its members' feedbacks.

Screening for down syndrome using trophoblast retrieval and isolation of the cervix: preliminary study

Purpose@#Trisomy 21, the cause of Down syndrome (DS) with various medical problems, is the most common aneuploidy during the fetal period. For diagnosis, a non-invasive screening test using maternal blood, which cannot be confirmed and invasive confirmation test with a risk of miscarriage, may be performed. The trophoblast retrieval and isolation of the cervix (TRIC) have been proposed by some researchers as an alternative to overcome the limitations of current tests. We experimented using TRIC to identify the possibility of trisomy 21 for the first time in Asia. @*Materials and Methods@#Three cases of DS were analyzed confirmed by invasive tests (chorionic villus sampling, amniocentesis). All samples of trophoblasts immediately were immersed in phosphate-buffered saline and processed with formalin for fixation. The trophoblasts were isolated using an anti-human leukocyte antigen-G antibody coupled to magnetic nanoparticles. β-human chorionic gonadotropin (hCG)-expressing cells were considered as trophoblast cells, and the detection rate calculated. DS was confirmed by fluorescence in situ hybridization (FISH). @*Results@#The mean trophoblast detection rate using β-hCG was 78.1%, and the detection rate using FISH was 22.2%. In all cases, the trisomy of chromosome 21 was identified. @*Conclusion@#Trophoblast can be obtained from the five weeks of gestation and has a high detection rate, so it is noted that it can replace the current prenatal genetic test. To realize the clinical application as a prenatal genetic test, we will need additional efforts to identify trisomy 21 as well as other chromosomal abnormalities in future large-scale studies.

Medical Issues and Opinions of Obstetrics Regarding Abortion Law Amendment

There have been ongoing social discussions on revision of the abortion law since the Constitutional Court ruled it nonconformity to the constitution on April 11, 2019. Thus, Korean Society of Obstetrics and Gynecology, Korean Society of Maternal Fetal Medicine, Korean College of Obstetricians and Gynecologists, and Korean Association of Obstetricians and Gynecologists organized 'special committee for abortion law' to support social discussion on the revision of the abortion law, and they prepared official opinions of obstetrics for medical issues including doctors' right to refuse abortion. In the future, the committee will continue to adapt to changes of medical environment especially after the revision of the abortion law by collecting its members' feedbacks.

Screening for down syndrome using trophoblast retrieval and isolation of the cervix: preliminary study

Purpose@#Trisomy 21, the cause of Down syndrome (DS) with various medical problems, is the most common aneuploidy during the fetal period. For diagnosis, a non-invasive screening test using maternal blood, which cannot be confirmed and invasive confirmation test with a risk of miscarriage, may be performed. The trophoblast retrieval and isolation of the cervix (TRIC) have been proposed by some researchers as an alternative to overcome the limitations of current tests. We experimented using TRIC to identify the possibility of trisomy 21 for the first time in Asia. @*Materials and Methods@#Three cases of DS were analyzed confirmed by invasive tests (chorionic villus sampling, amniocentesis). All samples of trophoblasts immediately were immersed in phosphate-buffered saline and processed with formalin for fixation. The trophoblasts were isolated using an anti-human leukocyte antigen-G antibody coupled to magnetic nanoparticles. β-human chorionic gonadotropin (hCG)-expressing cells were considered as trophoblast cells, and the detection rate calculated. DS was confirmed by fluorescence in situ hybridization (FISH). @*Results@#The mean trophoblast detection rate using β-hCG was 78.1%, and the detection rate using FISH was 22.2%. In all cases, the trisomy of chromosome 21 was identified. @*Conclusion@#Trophoblast can be obtained from the five weeks of gestation and has a high detection rate, so it is noted that it can replace the current prenatal genetic test. To realize the clinical application as a prenatal genetic test, we will need additional efforts to identify trisomy 21 as well as other chromosomal abnormalities in future large-scale studies.

Prenatal chromosomal microarray analysis of fetus with increased nuchal translucency

Nuchal translucency is an important indicator of an aneuploid fetus in prenatal diagnostics. Previously, only the presence of aneuploid could be confirmed by conventional karyotyping of fetuses with thick nuchal translucency. With the development of genetic diagnostic techniques, however, it has been reported that subtle variations not detectable by conventional karyotyping might occur in cases of pathologic clinical syndrome in euploid fetuses. One of the newer, high-resolution genetic methods in the prenatal setting is chromosomal microarray. The possible association between nuchal translucency thickness with normal karyotype and submicroscopic chromosomal abnormalities detectable by microarray has been studied. How and when to apply microarray in clinical practice, however, is still debated. This article reviews the current studies on the clinical application of microarray in cases of increased nuchal translucency with normal karyotype for prenatal diagnosis.

Korean physicians' attitudes toward the prenatal screening for fetal aneuploidy and implementation of non-invasive prenatal testing with cell-free fetal DNA

PURPOSE: Physicians' attitudes may have a strong influence on women's decision regarding prenatal screening options. The aim of this study is to assess the physicians' attitudes toward prenatal screening for fetal aneuploidy including non-invasive prenatal testing (NIPT) in South Korea. MATERIALS AND METHODS: Questionnaires were distributed and collected at several obstetrics-gynecological conferences and meetings. The questionnaire included 31 multiple choice and 5 fill-in-the-blank questions. Seven questions requested physicians' demographic information, 17 questions requested information about the NIPT with cell-free fetal DNA, and 12 questions requested information about general prenatal screening practices. RESULTS: Of the 203 obstetricians that completed the survey. In contrast with professional guidelines recommending the universal offering of aneuploidy screening, only 53.7% answered that prenatal aneuploidy testing (screening and/or invasive diagnostic testing) should be offered to all pregnant women. Physicians tended to have positive attitudes toward the clinical application of NIPT as both primary and secondary screening methods for patients at high-risk for fetal trisomy. However, for patients at average-risk for fetal trisomy, physicians tended to have positive attitudes only as a secondary screening method. Physicians with more knowledge about NIPT were found to tend to inform their patients that the detection rate of NIPT is higher. CONCLUSION: This is the first study to investigate expert opinion on prenatal screening in South Korea. Education of physicians is essential to ensure responsible patient counseling, informed consent, and appropriate management after NIPT.

A case of maternal uniparental disomy of chromosome 20 detected by noninvasive prenatal test of 1,000 high-risk pregnancies

Chromosomal loss in trisomy (trisomy rescue) to generate a disomic fetus can cause confined placental mosaicism and/or feto/placental mosaicism. After trisomy rescue event, there is a risk of fetal uniparental disomy (UPD). Noninvasive prenatal test (NIPT) reflects the genomic constitution of the placenta, not of the fetus itself. Feto-placental discrepancy can therefore cause false-positive (trisomy) NIPT results. These discordant NIPT results can serve as important clues to find UPD associated with confined placental mosaicism. We report a case with maternal UPD of chromosome 20, detected by NIPT of 1,000 high-risk pregnancies, carried out for detecting chromosomal abnormalities in Koreans.

Prenatal diagnosis of the isodicentric chromosome 22 associated with cat eye syndrome by multiplex ligation-dependent probe amplification

Cat eye syndrome (CES) is a very rare chromosomal syndrome characterized by various malformations such as anal atresia, preauricular malformation, coloboma of the iris, and congenial heart and renal defects. This genetic disorder is caused by partial duplication of chromosome 22, mostly as a result of a supernumerary isodicentric marker chromosome idic(22)(q11.2). Various congenital abnormalities and extreme phenotypic variability in CES patients have been reported, which have made prenatal diagnosis of CES difficult. We report the first case diagnosed with CES prenatally by multiplex ligation-dependent probe amplification in a woman who was referred to our hospital, for a fetus presenting with heart anomaly.

A 2-month-old boy with hemolytic anemia and reticulocytopenia following intravenous immunoglobulin therapy for Kawasaki disease: a case report and literature review / 소아과

Herein, we report a rare case of hemolytic anemia with reticulocytopenia following intravenous immunoglobulin therapy in a young infant treated for Kawasaki disease. A 2-month-old boy presented with fever lasting 3 days, conjunctival injection, strawberry tongue, erythematous edema of the hands, and macular rash, symptoms and signs suggestive of incomplete Kawasaki disease. His fever resolved 8 days after treatment with aspirin and high dose infusion of intravenous immunoglobulin. The hemoglobin and hematocrit decreased from 9.7 g/dL and 27.1% to 7.4 g/dL and 21.3%, respectively. The patient had normocytic hypochromic anemia with anisocytosis, poikilocytosis, immature neutrophils, and nucleated red blood cells. The direct antiglobulin test result was positive, and the reticulocyte count was 1.39%. The patient had an uneventful recovery. However, reticulocytopenia persisted 1 month after discharge.

An overview of current knowledge about cell-free RNA in amniotic fluid

Cell-free nucleic acids (cf-NAs) originate in trophoblasts and are detected in the maternal plasma. Using innovative bioinformatic technologies such as next-generation sequencing, cf-NAs in the maternal plasma have been rapidly applied in prenatal genetic screening for fetal aneuploidy. Amniotic fluid is a complex and dynamic fluid that provides growth factors and protection to the fetus. In 2001, the presence of cf-NA in amniotic fluid was reported. Amniotic fluid is in direct contact with the fetus and is derived from fetal urine and maternal and fetal plasma. Therefore, these genetic materials have been suggested to reflect fetal health and provide real-time genetic information regarding fetal development. Recently, several studies evaluated the global gene expression changes of amniot ic fluid cell-free RNA according to gestational age. In addition, by analyzing the transcriptome in the amniotic fluid of fetal aneuploidy, potential key pathways and novel biomarkers for fetal chromosomal aneuploidy were identified. Here, we review the current knowledge of cell-free RNA in amniotic fluid and suggest future research directions.

Carrier screening for (CGG)n repeat expansion of FMR1 gene in Korean women

PURPOSE: We examined the prevalence and CGG/AGG repeat structure of expanded alleles of the FMR1 gene in preconceptional and pregnant Korean women. MATERIALS AND METHODS: The CGG repeats in the FMR1 genes of 1,408 women were analyzed by polymerase chain reaction and Southern blot analysis. To estimate the prevalence of expansion alleles, the individuals were divided into low risk and high risk group. RESULTS: Within this population, 98.4% had normal alleles and 1.6% had abnormal alleles including intermediate (0.6%), premutation (0.5%), full mutation (0.1%), and hemizygous (0.4%) alleles. There were 2 premutation alleles (1:666, 95% confidence interval [CI] 1:250-1,776) in the low risk group and 5 premutation alleles (1:15, 95% 1:6-36) in the high risk group. There were 8 intermediate alleles (1:167, 95% CI 1:130-213) in the low risk group and 1 intermediate alleles (1:76, 95% CI 1:11-533) in the high group. Six of the 7 premutation alleles did not contain AGG interruptions within the repeats and 1 had a single AGG interruption. Four of the 9 intermediate alleles contained 2-3 AGG, 4 had a single AGG, and 1 had no AGG interruptions. CONCLUSION: Our study demonstrates the prevalence and CGG/AGG structure of expansion alleles in Korean women. The identified premutation prevalence is higher than that of other Asian populations and lower than that of Caucasian populations. Although our study is limited by size and population bias, our findings could prove useful for genetic counseling of preconceptional or pregnant women.

Low levels of tissue inhibitor of metalloproteinase-2 at birth may be associated with subsequent development of bronchopulmonary dysplasia in preterm infants / 소아과

PURPOSE: Bronchopulmonary dysplasia (BPD) is characterized by inflammation with proteolytic damage to the lung extracellular matrix. The results from previous studies are inconsistent regarding the role of proteinases and antiproteinases in the development of BPD. The aim of the present study was to investigate whether matrix metalloproteinase (MMP)-8, MMP-9, tissue inhibitor of metalloproteinase (TIMP)-2, and TIMP-1 levels in the serum of preterm infants at birth are related to the development of BPD. METHODS: Serum was collected from 62 preterm infants at birth and analyzed for MMP-8, MMP-9, TIMP-2, and TIMP-1 by using enzyme-linked immunosorbent assay. MMPs and TIMPs were compared in BPD (n=24) and no BPD groups (n=38). Clinical predictors of BPD (sex, birth weight, gestational age, etc.) were assessed for both groups. The association between predictors and outcome, BPD, was assessed by using multivariate logistic regression. RESULTS: Sex, birth weight, and mean gestational age were similar between the groups. BPD preterm infants had significantly lower TIMP-2 levels at birth compared with no BPD preterm infants (138.1+/-23.0 ng/mL vs. 171.8+/-44.1 ng/mL, P=0.027). No significant difference was observed in MMP-8, MMP-9, and TIMP-1 levels between the two groups. Multivariate logistic regression analysis indicated that the TIMP-2 levels were predictive of BPD after adjusting for sex, birth weight, gestational age, proteinuric preeclampsia, and intraventricular hemorrhage (beta=-0.063, P=0.041). CONCLUSION: Low TIMP-2 serum levels at birth may be associated with the subsequent development of BPD in preterm infants.

Maternal antimullerian hormone as a predictor of fetal aneuploidy occurring in an early pregnancy loss

OBJECTIVE: The purpose of the study was to examine the relationship between the parameter representing ovarian reserve and the fetal aneuploidy in early spontaneous miscarriage. METHODS: A multicenter retrospective cohort study was performed in patients who were diagnosed with early pregnancy loss (< or =13 gestational weeks) and examined for fetal karyotype at the CHA Gangnam Medical Center, CHA Bundang Medical Center, and CHA Gumi Medical Center between January 2011 and December 2012. Karyotyping was performed by the Genetic Laboratory of the Fertility Center of CHA Gangnam Medical Center. Medical records were reviewed for demographics, karyotype analysis and hormonal assay of ovarian reserve including antimullerian hormone (AMH) and follicle stimulating hormone. Statistical analysis was performed using SPSS software. RESULTS: A total 462 patients were included in this study. The mean age of the patients was 35.31+/-4.12 years and the mean AMH level was 3.88+/-3.50 ng/mL (n=195). Two hundred eleven conceptuses (45.7%) of patients showed the euploid and 251 (54.3%) showed the aneuploid. There are significant differences in maternal age, AMH and gestational age between fetal euploid and aneuploid groups (34.46+/-4.35 vs. 36.04+/-3.78 years, P<0.001; 4.60+/-3.86 vs. 3.43+/-3.18 ng/mL, P=0.022; 7.67+/-1.54 vs. 8.27+/-1.46 weeks, P<0.001, respectively). Multivariate analysis revealed that low AMH level and early gestational age were maternal age-independent markers for fetal aneuploid (P<0.001 and P=0.045, respectively). CONCLUSION: Low maternal AMH level might be a predicting marker for fetal aneuploid in early pregnancy loss.

Noninvasive prenatal test for the pregnancy with Turner syndrome mosaicism 45, X/47, XXX: A case report

Noninvasive prenatal test (NIPT) is a novel screening method for the diagnosis of fetal chromosomal aneuploidies. NIPT is based on technology that detects cell-free fetal DNA in maternal plasma and analyzes it with massively parallel sequencing technology to determine whether the fetus is at risk of trisomy 21, trisomy 18, trisomy 13 or sex chromosome abnormalities (SCAs). NIPT has been reported to have sensitivity of 99% and a false positive rate of less than 1% for detecting trisomy 21 and trisomy 18. Although extension of the application of NIPT to other SCAs has been attempted, there are concerns in extending NIPT to SCAs because of maternal or fetal mosaicism, undetected maternal SCAs, and multiple pregnancies. Recently, we assessed a pregnancy with the rare Turner syndrome mosaicism 45, X/47, XXX, which was reported as 45, X with NIPT. We present the case here and briefly review the current literatures on NIPT in testing for fetal monosomy X. To the best of our knowledge, this is the first report of the 45, X/47, XXX mosaicism in Korea to be reported as 45, X by NIPT with whole genome sequencing. This case report will provide valuable information for counseling women who want to undergo NIPT.

Characterization of a prenatally diagnosed de novo der(X)t(X;Y)(q27;q11.23) of fetus

A 31-year-old woman, who was pregnant with twins, underwent chorionic villus sampling because of increased nuchal translucency in one of the fetuses. Cytogenetic analysis showed a normal karyotype in the fetus with increased nuchal translucency. However, the other fetus, with normal nuchal translucency, had a derivative X chromosome (der(X)). For further analysis, fluorescence in situ hybridization (FISH) and additional molecular studies including fragile X analysis were performed. FISH analysis confirmed that the Y chromosome was the origin of extra segment of the der(X). The X-chromosome breakpoint was determined to be at Xq27 by FMR1 CGG repeat analysis, and the Y-chromosome breakpoint was determined to be at Yq11.23 by the Y chromosome microdeletion study. To predict the fetal outcome, the X-inactivation pattern was examined, and it revealed non-random X inactivation of the der(X). To the best of our knowledge, the identification of an unbalanced Xq;Yq translocation at prenatal diagnosis has never been reported. This study was performed to identify precise breakpoints and the X-inactivation pattern as well as to provide the parents with appropriate genetic counseling.

Spontaneous ovarian hyperstimulation syndrome following a thawed embryo transfer cycle / 대한생식의학회지

This article reports a case of spontaneous ovarian hyperstimulation syndrome (OHSS) following a thawed embryo transfer cycle. OHSS, a potentially life-threatening condition, is an iatrogenic complication of controlled ovarian stimulation; therefore, it is very important to prevent and treat OHSS during treatment with ovulation-inducing agents. Despite our efforts to prevent OHSS, in this case, severe spontaneous OHSS occurred, which resulted in uncontrolled preterm labor and a preterm delivery and also persisted for 6 weeks after delivery. Freezing all embryos cannot entirely prevent the development of OHSS because OHSS can occur spontaneously. Although spontaneous OHSS remains a rare event, females with a history of OHSS may have an elevated risk for spontaneous OHSS. We suggest closely monitoring cases of pregnancy following thawed embryo transfer for early diagnosis of spontaneous OHSS and the use of conservative management.