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.

Prenatal Diagnosis of Congenital Heart Diseases and Associations with Serum Biomarkers of Aneuploidy: A Multicenter Prospective Cohort Study

Purpose@#We assessed prenatal detection rates of congenital heart disease (CHD) and associations between maternal serum biomarkers and non-chromosomal CHD in singleton pregnancies. @*Materials and Methods@#This study was conducted as a secondary analysis of data obtained during a multicenter prospective cohort study that investigated the cost-effectiveness of prenatal testing for fetal aneuploidy. We analyzed the prenatal detection rate and accuracy for CHD screening via ultrasound during the second trimester, as well as associations between serum biomarkers and CHDs, in singleton newborns without chromosomal abnormalities. @*Results@#Among 6715 women, 142 (2.1%) newborns were born with CHDs, of which 67 (1.0%) newborns had major CHDs. The prenatal detection rate for all CHDs and major CHDs were 34.5% and 58.2%, respectively. After excluding isolated ventricular septal defects, the detection rate for critical CHDs was 85.9%. Women with low pregnancy-associated plasma protein A (PAPP-A) (<0.4 multiples of the median, MOM) face increased risks of non-chromosomal CHDs [adjusted odds ratio (aOR) 2.76; 95% confidence interval (CI) 1.36–5.13] and major CHDs (aOR 7.30; 95% CI 3.18–15.59), compared to those without CHDs. A higher inhibin A level (≥2.5 MOM; aOR 4.84; 95% CI 1.42–12.46) was associated with non-chromosomal major CHDs. @*Conclusion@#Ultrasonography performed during the second trimester by obstetricians detected over 85% of critical CHDs. Low maternal serum PAPP-A or high inhibin-A was associated with non-chromosomal CHDs. These results may contribute to an improvement in prenatal diagnosis of CHDs.

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.

Elevated Alanine Aminotransferase in Early Pregnancy and Subsequent Development of Gestational Diabetes and Preeclampsia

Background@#Nonalcoholic fatty liver disease (NAFLD) is now considered as a hepatic manifestation of metabolic syndrome and elevated alanine aminotransferase (ALT) is commonly related to NAFLD in the absence of viral hepatitis or alcohol abuse. Previous studies have indicated that elevated ALT is associated with diabetes or metabolic syndrome in adults, but the clinical significance of ALT or NAFLD in pregnancy has not been well determined. The objective of this study was to determine the association between elevated ALT in early pregnancy and the development of gestational diabetes or preeclampsia in late pregnancy. @*Methods@#In this retrospective cohort study, pregnant women who met the following inclusion criteria were included: 1) singleton pregnancy; 2) ALT levels were measured in antenatal outpatient clinic at 4–20 weeks of gestation; 3) patients were screened for gestational diabetes and delivered in Cheil General Hospital and Women's Healthcare Center. Cases with viral hepatitis or other liver diseases were excluded. The early ALT levels were divided into two groups (normal ALT [≤ 95th percentile] and elevated ALT [> 95th percentile]), and the frequency of gestational diabetes and preeclampsia was compared between the two groups of cases. Gestational diabetes was screened and diagnosed by two-step procedure (50 g oral glucose challenge test and 75 g glucose challenge test with World Health Organization [WHO] criteria). @*Results@#A total of 2,322 women met the inclusion criteria. Cases with elevated early ALT levels (> 95th percentile) had a higher risk of subsequent gestational diabetes and preeclampsia (gestational diabetes by WHO criteria, 2.1% in normal ALT vs. 6.5% in elevated ALT, P < 0.01; preeclampsia, 1.0% in normal ALT vs. 4.1% in elevated ALT, P < 0.05). This relationship between elevated ALT and increased risk of gestational diabetes/preeclampsia remained significant after adjustment for maternal age and pre-pregnancy body mass index. @*Conclusion@#Elevated unexplained ALT in early pregnancy is associated with the risk of subsequent development of gestational diabetes and preeclampsia in late pregnancy.

Height of elevated fetal buttock for prediction of successful external cephalic version

14 cm, and HOB >7.8 cm were 10.80 (95% confidence interval [CI], 1.57–74.94), 5.26 (95% CI, 1.06–26.19), and 10.50 (95% CI, 1.03–107.12), respectively. Areas under the curve (AUCs) for AFI, HOB, and parity were 0.66 (95% CI, 0.54–0.78), 0.74 (95% CI, 0.64–0.85), and 0.69 (95% CI, 0.62–0.76), respectively. HOB had the largest AUC, but there were no significant differences among the AUCs of other factors. The cut-off value of HOB was 6 cm.CONCLUSION: This study showed that the AUC of HOB was greater than that of parity and AFI, although it was not statistically significant. As HOB is a noninvasive and comprehensive marker to predict successful ECV, consideration of HOB would be helpful before conducting ECV. Further studies are needed.

Treatment of gestational diabetes diagnosed by the IADPSG criteria decreases excessive fetal growth

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.

The clinical usefulness of non-invasive prenatal testing in pregnancies with abnormal ultrasound findings

PURPOSE: This study aimed to evaluate the clinical usefulness of non-invasive prenatal testing (NIPT) as an alternative testing of invasive diagnostic testing in pregnancies with ultrasound abnormalities. MATERIALS AND METHODS: This was a retrospective study of pregnant women with abnormal ultrasound findings before 24 weeks of gestation between April 2016 and March 2017. Abnormal ultrasound findings included isolated increased nuchal translucency, structural anomalies, and soft markers. The NIPT or diagnostic test was conducted and NIPT detected trisomy 21 (T21), T18, T13 and sex chromosomal abnormalities. We analyzed the false positive and residual risks of NIPT based on the ultrasound findings. RESULTS: During the study period, 824 pregnant women had abnormal ultrasound findings. Among the study population, 139 patients (16.9%) underwent NIPT. When NIPT was solely performed in the patients with abnormal ultrasound findings, overall false positive risk was 2.2% and this study found residual risks of NIPT. However, the discordant results of NIPT differed according to the type of abnormal ultrasound findings. Discordant results were significant in the group with structural anomalies with 4.4% false positive rate. However, no discordant results were found in the group with single soft markers. CONCLUSION: This study found different efficacy of NIPT according to the ultrasound findings. The results emphasize the importance of individualized counseling for prenatal screening or diagnostic test based on the type of abnormal ultrasound.

Change in rates of prenatal tests for chromosomal abnormality over a 12-year period in women of advanced maternal age

OBJECTIVE: In 2007, the American College of Obstetricians and Gynecologists (ACOG) recommended that all pregnant women be offered screening or diagnostic tests for chromosomal abnormalities regardless of their age. Noninvasive prenatal testing (NIPT) for common chromosomal aneuploidies was introduced as a screening test in case of high-risk pregnancies. We assessed the rates of prenatal tests in women aged 35 years and older. METHODS: A retrospective study was conducted to compare the rates of amniocentesis, chorionic villus sampling (CVS), serum screening, and NIPT from January 2005 through March 2017 in women aged 35 years and older. We divided the initial 12 months after NIPT introduction into 4-month intervals, beginning in April 2016 through March 2017. RESULTS: The rates of amniocentesis were 56% before the ACOG statement, 38% between the ACOG statement and NIPT introduction, and 10% after NIPT introduction (P=0.001). The rates of CVS during the same periods were 0.5%, 2.1%, and 4.3% (P=0.016), respectively. The rates of serum screening were 44.2%, 61.3%, and 55.1% (P=0.049), respectively. During the 3 quarters after NIPT introduction, the rates of amniocentesis were 16.2%, 12.3%, and 7.3% (P=0.002), respectively; the rates of serum screening were 62%, 54%, and 46% (P=0.03), respectively; and the rates of NIPT were 19.9%, 30.3%, and 39.5% (P=0.007), respectively. The rates of CVS over the same periods were not significantly different. CONCLUSION: The ACOG statement and NIPT introduction significantly decreased the rate of amniocentesis in women of advanced maternal age. NIPT also reduced the rate of serum screening.

Role of fetal ultrasound in prenatally diagnosed de novo balanced translocations

PURPOSE: This study aimed to investigate fetal ultrasonographic findings in cases of prenatally diagnosed de novo balanced translocations and the role of fetal ultrasound in prenatal genetic counseling. MATERIALS AND METHODS: We collected cases with de novo balanced translocations that were confirmed in chorionic villus sampling, amniocentesis, and cordocentesis between 1995 and 2016. A detailed, high-resolution ultrasonography was performed for prediction of prognosis. Chromosomes from the parents of affected fetuses were also analyzed to determine whether the balanced translocations were de novo or inherited. RESULTS: Among 32,070 cases with prenatal cytogenetic analysis, 27 cases (1/1,188 incidence) with de novo balanced translocations were identified. Fourteen cases (51.9%) showed abnormal findings, and the frequency of major structural anomalies was 11.1%. Excluding the major structural anomalies, all mothers who continued pregnancies delivered healthy babies. CONCLUSION: Results of a detailed, high-resolution ultrasound examination are very important in genetic counseling for prenatally diagnosed de novo balanced translocations.

Maternal Thyroid Function during the First Trimester of Pregnancy in Korean Women

BACKGROUND AND OBJECTIVES: Thyroid dysfunction during pregnancy can result in many complications for both mother and infant. Due to the physiologic changes in thyroid stimulating hormone (TSH) level during early pregnancy, it is recommend to use trimester-specific reference ranges for every population. We obtained the reference range of TSH during the first trimester in Korean women according to gestational week. MATERIALS AND METHODS: The study population consisted of pregnant women who had undergone a TSH screening during the first trimester of pregnancy (n=8365) and nonpregnant women (n=1835). RESULTS: Median concentration of serum TSH decreased significantly from the 5th to 8th week of gestation (median TSH concentration: 2.00 mIU/L for 5 weeks; 1.70 mIU/L for 6 weeks; 1.40 mIU/L for 7 weeks; 1.05 mIU/L for 8 weeks). However, there was no significant difference in median concentration of serum TSH from the 8th to 12th weeks of gestation. Using the fixed cut-off value of TSH >3.66 mIU/L, the diagnosis rate of subclinical hypothyroidism was 15.0% for 5 weeks, 10.0% for 6 weeks, 5.9% for 7 weeks, and 3.6% for 8-12 weeks. CONCLUSION: When interpreting the TSH test for pregnancy (maternal thyroid function), we should consider that the TSH level decreases significantly during the early first trimester.

Prediction of Amnionicity Using the Number of Yolk Sacs in Monochorionic Multifetal Pregnancy

The purpose of this article was to evaluate the accuracy of predicting amnionicity using the number of yolk sacs by diagnostic ultrasound examination in monochorionic (MC) multifetal pregnancies between 7 + 0 and 9 + 6 gestational weeks. A total of 97 patients with MC multifetal pregnancies underwent early ultrasound examination from 2004 to 2014 at Cheil General Hospital and Women's Healthcare Center. All patients for whom the number of yolk sacs was reported were included in this study. We compared the number of yolk sacs with amnionicity confirmed by an intertwine membrane. Overall, there was a 9.3% (9 cases) discrepancy in number of yolk sacs and amnionicity (4.3% for monochorionic diamniotic, 36.4% for monochorionic monoamniotic, and 33% for monochorionic triamniotic). Among the 9 cases with discrepancies, 4 cases with 2 yolk sacs were confirmed as monoamniotic pregnancies and 4 MC twin pregnancies showing a single yolk sac were diagnosed as diamniotic twin pregnancies. One case with 2 yolk sacs was identified as a triamniotic triplet pregnancy. In 9.3% of MC gestations, the number of yolk sacs was not correlated with the number of amnions in our study. To determine amnionicity in MC multifetal pregnancies, we recommend careful evaluation not of the number of yolk sacs but the presence or absence of intertwine dividing membrane after 8 gestational weeks.

First trimester screening for trisomy 18 by a combination of nuchal translucency thickness and epigenetic marker level

PURPOSE: The aim of this study was to assess the diagnostic efficacy of noninvasive prenatal screening for trisomy 18 by assessing the levels of unmethylated-maspin (U-maspin) and fetal nuchal translucency (NT) thickness during the first trimester of pregnancy. MATERIALS AND METHODS: A nested case-control study was conducted using maternal plasma samples collected from 65 pregnant women carrying 11 fetuses with trisomy 18 and 54 normal fetuses. We compared the U-maspin levels, NT thicknesses, or a combination of both in the first trimester between the case and control groups. RESULTS: U-maspin levels and NT thickness were significantly elevated in the first trimester in pregnant women carrying fetuses with trisomy 18 when compared to those carrying normal fetuses (27.2 vs. 6.6 copies/mL, P<0.001 for U-maspin; 5.9 vs. 2.0mm, P<0.001 for NT). The sensitivities of the U-maspin levels and NT thickness in prenatal screening for fetal trisomy 18 were 90.9% and 90.9%, respectively, with a specificity of 98.1%. The combined U-maspin levels and NT thickness had a sensitivity of 100% in prenatal screening for fetal trisomy 18, with a specificity of 98.1%. CONCLUSION: A combination of U-maspin levels and NT thickness is highly efficacious for noninvasive prenatal screening of fetal trisomy 18 in the first trimester of pregnancy.

Prenatal diagnosis of 5p deletion syndrome: A case series report

5p deletion syndrome, also known as Cri-du-Chat syndrome, is a chromosomal abnormality caused by a deletion in the short arm of chromosome 5. Clinical features of 5p deletion syndrome are difficult to identify prenatally by ultrasound examination, thus most cases of 5p deletion syndrome have been diagnosed postnatally. Here, we report eight cases of 5p deletion syndrome diagnosed prenatally, but were unable to find common prenatal ultrasound findings among these cases. However, we found that several cases of 5p deletion syndrome were confirmed prenatally when karyotyping was performed on the basis of abnormal findings in a prenatal ultrasound scan. Hence, it is necessary to carefully perform prenatal ultrasonography for detection of rarer chromosomal abnormalities as well as common aneuploidy.

Effects of Serum 25-hydroxy-vitamin D and Fetal Bone Growth during Pregnancy

BACKGROUND: This study was conducted to observe the prevalence of vitamin D deficiency during pregnancy and the effects of maternal 25-hydroxy-vitamin D (25-[OH]D) levels on fetal bone growth. METHODS: Five hundred twenty-three Korean pregnant women were randomly recruited and serum 25-(OH)D level was measured. During pregnancy, fetal ultrasonography and serum 25-(OH)D measurements were carried out 3 times in 275 of 523 pregnant women. Fetal biparietal and occipitofrontal diameter, head and abdominal circumference, and femur and humerus length were measured through fetal ultrasonography. RESULTS: The prevalence of vitamin D deficiency (25-[OH]D<20 ng/mL) based on the 1st serum measurement of 25-(OH)D was 88.9%. There was no association between maternal serum 25-(OH)D level and fetal bone growth. In 275 pregnant women who completed study design, the mean value of 25-(OH)D was 12.97+/-5.93, 19.12+/-9.82, and 19.60+/-9.98 ng/mL at 12 to 14, 20 to 22, and 32 to 34 weeks of pregnancy, respectively and there was an association between the difference of serum 25-(OH)D level between 12 to 14 and 20 to 22 weeks and growth velocity of fetal biparietal diameter between 20 to 22 and 32 to 34 weeks of pregnancy. CONCLUSIONS: This study shows a high prevalence of vitamin D deficiency in Korean pregnant women and the change of serum 25-(OH)D levels is related with the growth of fetal biparietal diameter, however other parameters are not associated with serum 25-(OH)D levels.

Observed frequency of fetal trisomy between 16 and 24 gestational weeks in pregnant women older than 34 years at delivery

PURPOSE: Increased maternal age is a major risk factor for chromosomal abnormalities. The maternal age-specific risk of fetal trisomy was theoretically calculated. We investigated the actual frequency of fetal trisomy between 16 and 24 gestational weeks in pregnant women over the age of 34 at delivery. MATERIALS AND METHODS: We retrospectively, over a four-year period, reviewed the medical records of women with singleton pregnancies that started their antenatal care before the 10th week of pregnancy. Pregnant women aged 34 to 45 years at the time of delivery were enrolled and divided into groups of one-year intervals. We investigated the frequency of Down syndrome and all trisomies as a function of the maternal age and compared with the theoretical maternal-age-specific risk. RESULTS: Of the 5,858 pregnant women enrolled in the study, the rate of trisomy 21 was 0.29% (17 cases). The observed frequencies of trisomy 21 in women with maternal ages of 35 years and 40 years were 1:1,116 and 1:141, respectively. The rate of all trisomies was 0.39% (23 cases). The observed frequencies of all trisomies in women with maternal ages of 35 years and 40 years were 1:372 and 1:56, respectively. CONCLUSION: The frequencies of Down syndrome and all trisomies were proportional to the maternal age. However, the observed frequencies of Down syndrome and all trisomies between the 16 and 24 gestational weeks were lower than the theoretical rates.

Gestational weight gain is an important risk factor for excessive fetal growth

OBJECTIVE: To estimate the odds ratio of prepregnant body mass index (BMI), gestational weight gain (GWG), and gestational diabetes mellitus (GDM) for excessive fetal growth, which we define as large for gestational age (LGA). METHODS: We included 16,297 women who delivered a live-born singleton baby at term. We fit logistic regressions to estimate the odds ratios of variables, including maternal age, parity, prepregnant BMI > or =23, GWG > or =15 kg, and GDM, for LGA. We classified GWG into four categories ( or =20 kg) and BMI into four categories (underweight, normal, overweight, and obese). After adjusting for age and parity, we analyzed the odds ratios of prepregnant BMI according to GWG between non-GDM and GDM women for LGA. RESULTS: The odds ratios of GWG > or =15 kg and prepregnancy BMI > or =23 for LGA were 2.40 (95% confidence interval [CI], 2.16-2.67) and 2.24 (95% CI, 1.99-2.51), respectively. The odd ratio of GDM was 1.37 (95% CI, 1.09-1.71). The risk of GDM women with normal/-overweight BMI and GWG or =15 kg might be a more important risk factor for LGA than either prepregnancy BMI > or =23 or GDM. Risk for LGA was highest in obese GDM women with GWG > or =15 kg.

Fetal Loss Rate after Mid-trimester Amniocentesis

PURPOSE: The aim of this study was to asses the fetal loss rate after mid-trimester amniocentesis. MATERIALS AND METHODS: This was a retrospective cohort study including singleton pregnant women who underwent mid-trimester amniocentesis at Cheil General Hospital from January 2008 through December 2010. The procedure-related fetal loss was defined as miscarriage within 2 weeks after amniocentesis. We evaluated the fetal loss rate within 2 weeks after amniocentesis and fetal loss rate before 24 gestational weeks. RESULTS: During the study period, a total of 4,356 singleton pregnant women underwent mid-trimester amniocentesis. A total of Five hundred ninety six women were excluded owing to follow up loss and termination of pregnancy due to abnormal karyotype or major anomaly. At our institute, the fetal loss rate within 2 weeks was 0.1% and before 24 gestational weeks was 0.3% after amniocentesis. CONCLUSION: The fetal loss rate after mid-trimester amniocentesis in our study is lower than previously reported rate. We suggest that amniocentesis is a safe procedure.

Prenatal Genetic Test

Genetic testing has been generalized for the diagnosis of diseases and is an important method of research with advances in the life sciences. In particular, we should give better attention to the genetic test for a fetus. Because the fetus has no autonomy, ethical and social issues can arise. Therefore, appropriate genetic counseling is needed for parents to be informed with the characteristics, natural progress, and possible treatment of a genetic disease, prior to the prenatal genetic test. Physicians should also inform parents how a particular genetic risk factor relates with the likelihood of a disease, in order to assist the parents in making the best decision. Furthermore, the current law for prenatal genetic testing should be approached rationally.