High-frequency ultrasound imaging to assess fetal pancreas: a promising application.

Objectives: The purpose of this study is to establish a comprehensive reference range of quantitative characteristics of the fetal pancreas using a high-frequency transducer, and assess the growth and development of the fetal pancreas.Methods: Pregnant women referred to a tertiary center were recruited to undergo a detailed fetal scan from 16 to 37 weeks. We evaluated the visualization rate of the fetal pancreas with high-frequency and low-frequency transducers and measured the head, neck, body, tail, circumference, area, and abdominal circumference(AC) of the fetal pancreas at different gestational ages(GA) with the high-frequency transducer. Regression analysis was used to analyze the relationship between biological parameters and GA and AC.Results: During the time periods of 16+1∼21+6 weeks and 22+1∼27+6 weeks, the visualization rate of high-frequency transducers was higher compared to low-frequency transducers (83.33% vs 45% and 95.65% vs 70%, respectively). However, in the third trimester of pregnancy, the performance of the two transducers was similar (70.37% vs 74.07% for 28+1∼33+6 weeks and 41.67% vs 53.85% for 34+1∼37+6 weeks). The head, neck, body, and tail as well as the circumference and area of the pancreas were significantly positively correlated with GA (R2＝0.87, 0.94, 0.92, 0.92,0.96, and 0.92) and AC (R2＝0.87, 0.93, 0.91, 0.93,0.96, and 0.92).Conclusions: The high-frequency transducer was utilized to establish the normal reference, which can be used to evaluate normal pancreatic development and may help in the accurate diagnosis of fetal pancreatic abnormalities.

Application of elastography to diagnose adenomyosis and evaluate the degree of dysmenorrhea: a prospective observational study.

BACKGROUND: To determine whether there is a correlation between stiffness measured by strain elastography and the severity of dysmenorrhea and to determine the value of elastography in evaluating severe dysmenorrhea in patients with adenomyosis. METHODS: The correlation between tissue stiffness and dysmenorrhea was analyzed by performing elastography on premenopausal women diagnosed with adenomyosis. Expression levels of transforming growth factor-ß (TGF-ß), α-smooth muscle actin (α-SMA), and protein gene product 9.5 (PGP9.5) were detected by immunohistochemistry; the correlation of TGF-ß and α-SMA levels with the tissue stiffness and the degree of fibrosis was further analyzed. Also, the relationship of the PGP9.5 expression level with the tissue stiffness and degree of dysmenorrhea was determined. RESULTS: The degree of dysmenorrhea was significantly positively correlated with lesion stiffness in patients with adenomyosis but not with the uterine or lesion volume. The cutoff for the strain ratio was > 1.36 between the adenomyosis and control groups, with an area under the curve (AUC) of 0.987. For severe dysmenorrhea, the cutoff for the strain ratio was > 1.65 in patients with adenomyosis, with an AUC of 0.849. TGF-ß, α-SMA, and PGP9.5 expression levels were higher in adenomyotic lesions than in the endometrium of the adenomyosis and control groups. Both TGF-ß and α-SMA levels were positively correlated with the tissue stiffness and degree of fibrosis. Additionally, the expression level of PGP9.5 showed a positive correlation with the tissue stiffness and degree of dysmenorrhea. CONCLUSIONS: Elastography can be used to evaluate the degree of dysmenorrhea; the greater the tissue stiffness, the greater the degree of dysmenorrhea. In addition, elastography performed well in the diagnosis of adenomyosis and the evaluation of severe dysmenorrhea in patients with adenomyosis.

Cesarean Scar Ectopic Pregnancy Clinical Classification System With Recommended Surgical Strategy.

OBJECTIVE: To establish a new cesarean scar ectopic pregnancy clinical classification system with recommended individual surgical strategy and to evaluate its clinical efficacy in treatment of cesarean scar ectopic pregnancy. METHODS: This retrospective cohort study included patients with cesarean scar ectopic pregnancy in Qilu Hospital in Shandong, China. From 2008 to 2015, patients with cesarean scar ectopic pregnancy were included to determine risk factors for intraoperative hemorrhage during cesarean scar ectopic pregnancy treatment. Univariable analysis and multivariable logistic regression analyses were used to explore the independent risk factors for hemorrhage (300 mL or greater) during a cesarean scar ectopic pregnancy surgical procedure. The model was internally validated with a separate cohort. Receiver operating characteristic curve methodology was used to identify optimal thresholds for the identified risk factors to further classify cesarean scar ectopic pregnancy risk, and the recommended operative treatment was established for each classification group by expert consensus. A final cohort of patients from 2014 to 2022 were classified according to the new classification system, and the recommended surgical procedure and clinical outcomes were abstracted from the medical record. RESULTS: Overall, 955 patients with first-trimester cesarean scar ectopic pregnancy were included; 273 were used to develop a model to predict intraoperative hemorrhage with cesarean scar ectopic pregnancy, and 118 served as an internal validation group for the model. Anterior myometrium thickness at the scar (adjusted odds ratio [aOR] 0.51, 95% CI 0.36-0.73) and average diameter of the gestational sac or mass (aOR 1.10, 95% CI 1.07-1.14) were independent risk factors for intraoperative hemorrhage of cesarean scar ectopic pregnancy. Five clinical classifications of cesarean scar ectopic pregnancy were established on the basis of the thickness and gestational sac diameter, and the optimal surgical option for each type was recommended by clinical experts. When the classification system was applied to a separate cohort of 564 patients with cesarean scar ectopic pregnancy, the overall success rate of recommended first-line treatment with the new classification grouping was 97.5% (550/564). No patients needed to undergo hysterectomy. Eighty-five percent of patients had a negative serum ß-hCG level within 3 weeks after the surgical procedure; 95.2% of patients resumed their menstrual cycles within 8 weeks. CONCLUSION: Anterior myometrium thickness at the scar and the diameter of the gestational sac were confirmed to be independent risk factors for intraoperative hemorrhage during cesarean scar ectopic pregnancy treatment. A new clinical classification system based on these factors with recommended surgical strategy resulted in high treatment success rates with minimal complications.

Prenatal ultrasonographic features and follow-up outcomes of 19 cases of congenital intrahepatic portosystemic venous shunts diagnosed during the foetal period.

BACKGROUND: To investigate the prenatal ultrasonographic features and case characteristics of the congenital intrahepatic portosystemic venous shunt (IHPSS) diagnosed during the foetal period and analyse its prognosis. METHODS: We conducted a retrospective cohort study of patients diagnosed with IHPSS between 2016 and 2021. IHPSS was defined as an abnormal connection between the foetal intrahepatic portal and the hepatic veins. RESULTS: In this study, 19 foetuses were identified, including 12 cases of single shunt and 7 cases of multiple shunts, with a gestational age of 33.8 ± 4.5 (range 25-40) weeks at diagnosis. In the single-shunt group, the origin position of the shunts was all from the left branch of the portal vein (LPV), whereas in the multiple-shunt group, the origin position of the shunts was from the LPV in six cases. Common concomitant intrauterine abnormalities of IHPSS include foetal growth restriction (47.4%) and foetal cardiac enlargement (21.1%). The postnatal manifestations of IHPSS include biochemical abnormalities (increased gamma-glutamyl transferase and bilirubin levels), neonatal hypoglycaemia, neonatal hyperammonaemia, pulmonary hypertension, multiple intrahepatic hyperechoic nodules, and cutaneous haemangiomas. Spontaneous closure of shunts occurred in ten cases, and the mean time to shunt closure was 8.1 months (1-28 months). CONCLUSIONS: Most IHPSS found during the foetal period is located in the left branch of the portal vein, and the gestational age at diagnosis is usually in the late second or third trimester. Spontaneous closure of shunts can occur in most live births, and the prognosis is good.

Ultrasonographic characteristics and outcome of Type III umbilical-portal-systemic venous shunt.

AIMS: According to a novel in-utero classification termed "umbilical-portal-systemic venous shunt (UPSVS)" recently proposed for an abnormal umbilical, portal and ductal venous system, the portal-systemic shunt belongs to type III UPSVS. This study was designed to examine the ultrasonographic characteristics and outcome of type III UPSVS.Material and methods: All cases of Type III UPSVS diagnosed at our department from April 2016 to December 2020 were retrospectively studied. RESULTS: Seventeen patients with type III UPSVS including 12 type IIIa and 5 IIIb cases were identified. Sonography showed a shunt between the inferior left portal vein and the left hepatic vein in all type IIIa cases. Three cases of type IIIb had a combination of another shunt (2 with type I and one with type IIIa). Integrate intrahepatic portal vein system was not seen in those 2 cases of type IIIb combined with type I UPSVS, leading to termination of pregnancy (TOP). TOP occurred in 4 patients with type IIIa as requested by the parents. Two cases (type IIIa and type IIIb each) underwent surgical procedure for the closure of the shunt. Spontaneous complete closure in 4 type IIIa cases and partial closure in one type IIIb case occurred during a period of 3-16 months. CONCLUSIONS: The majority of patients had type IIIa UPSVS presenting a good outcome. The lack of integrate intrahepatic portal vein system was the main reason for TOP in patients with type IIIb UPSVS. These data suggest the UPSVS classification is a useful tool for a prognosis prediction of type III UPSVS.

Are fetal gender and gestational age related to the size of cisterna magna?

OBJECTIVES: The purpose of this article was to explore whether the gestational age(GA)and gender could affect the size of the cisterna magna (CM). METHODS: This study that included pregnant women who were between 20 ∼ 39+6. The recorded included BPD, HC, anteroposterior diameter of CM and gender. The fetuses were divided into normal and isolated enlargement of the CM (IECM)group for statistical analysis. RESULTS: Seven hundred ninety six fetuses with normal CM, 412 cases were boys and 384 cases were girls. 73 fetuses with IECM, 59 cases were boys and 14 cases were girls. The anteroposterior diameter of the CM increased with GA during 20-26+6 weeks. After 27 weeks, the anteroposterior diameter of CM became stable. In the IECM group, the mean anteroposterior of male and female fetuses were 1.31 ± 0.18 cm and 1.24 ± 0.15 cm, respectively. The IECM fetus accounted for 8.4% of the total number of fetuses, male IECM accounted for 14.3% of normal male fetus, and female fetus was 3.6%, which showed that male fetus had a higher rate of IECM than female (χ2 = 21.6, p<.001). CONCLUSIONS: There is a gender difference between normal fetuses and IECM fetuses. Based on our finding, it is reasonable to establish the normal value of CM according to the gender difference.

Role of Abdominal Aortic Balloon Placement in Planned Conservative Management of Placenta Previa With Placenta Increta or Percreta.

Background: We investigated the role of balloon placement in the abdominal aorta (BPAA) in planned conservative management of placenta previa with placenta increta or percreta and the effects of BPAA on perinatal adverse maternal events. Methods: This retrospective case-control study included women with placenta previa (increta or percreta), who underwent pregnancy termination at the Qilu Hospital of Shandong University between January 2016 and June 2019. Patients were categorized into the BPAA and non-BPAA groups based on the BPAA placement before delivery. The Chi-square and non-parametric rank-sum tests were used for the intergroup comparison of patient characteristics. The propensity score matching algorithm was used to minimize the intergroup differences in clinical characteristics. Logistic regression analysis was used to identify the factors associated with a high risk of adverse pregnancy outcomes. The area under the receiver operating characteristic curve [area under the curve (AUC)] was used to evaluate the classification of the selected high-risk factors. Results: The study included 260 patients, and 104 patients were identified after propensity score matching. In the post-matched cohort, intraoperative blood loss was significantly lower in the BPAA than in the non-BPAA group (median 1,000 vs. 2,250 ml, P < 0.001). Intraoperative B-Lynch suture was performed in fewer patients in the BPAA (15.4 vs. 34.6%, P = 0.024) than in the non-BPAA group. The packed red blood cell (PRBC) transfusion rate was lower in the BPAA group (median 4 vs. 8 units, P < 0.001). Overall, 46 (45.1%) patients developed adverse maternal events; however, the rate of adverse maternal events was lower in the BPAA group (19.6 vs. 80.4%, P < 0.001). No ligation of the ascending branch of the uterine artery (P = 0.034), no BPAA (P < 0.001), intraplacental vascular lacunae (P = 0.046), and cervical hypervascularity (P = 0.001) were associated with a high risk of adverse perinatal maternal events. The AUC of the high-risk factors was 0.89 in the post-matched and 0.76 in the pre-matched cohorts. Conclusion: Planned conservative management using BPAA significantly minimized the intraoperative blood loss, the need for a B-Lynch suture, and PRBC transfusion in patients with severe placenta accreta spectrum and placenta previa.

Prenatal Ultrasound Analysis of Umbilical-Portal-Systemic Venous Shunts Concurrent With Trisomy 21.

OBJECTIVES: A classification termed umbilical-portal-systemic venous shunt (UPSVS) for an abnormal umbilical vein (UV), portal vein (PV), and ductus venosus (DV) was proposed recently. According to this classification, there are 3 types of UPSVSs: types I, II, and III. Trisomy 21 associated with UV-PV-DV anomalies has been described, but the incidence of trisomy 21 in UPSVS cases, the relationship between UPSVS types and trisomy 21, and the pregnancy outcome are poorly documented. This study aimed to address these issues. METHODS: All UPSVS cases diagnosed at our department from 2016 to 2019 were retrospectively studied. The English literature describing UV-PV-DV anomalies and trisomy 21 from 2000 to 2019 was searched, and the retrieved cases were analyzed. RESULTS: Four of 20 UPSVS cases identified by us also had trisomy 21, with 2 type I and 2 type II UPSVSs. Ultrasound markers of Down syndrome were observed in all 4 cases that underwent termination of pregnancy (TOP). The literature search retrieved 12 reports including 279 patients, with 29 also having trisomy 21, giving a pooled trisomy 21 incidence rate of 10.4%. Of the 29 cases, 16 had type I, and 9 had type II, whereas UPSVS types in 4 were undeterminable, and 22 cases underwent TOP. CONCLUSIONS: There is a high incidence of trisomy 21 in UPSVS cases. Trisomy 21 is associated with a type I or II UPSVS. Most cases with the combined defect underwent TOP. These findings may be used to direct prenatal counseling and management of the combined condition.

Effect of head circumference in combination with facial profile line on ultrasonic diagnosis of microcephaly.

Objective: Recently, microcephaly has usually been misdiagnosed only by ultrasound via measurement of head circumference (HC). Therefore, the aim of this study is to find another diagnostic index to supplement the original diagnostic method of microcephaly, to improve the detection rate of fetal microcephaly and to reduce the misdiagnosis rate.Methods: We retrospectively analyzed 123 pregnant women from February 2012 to January 2017 with fetal HC less than two standard deviations (SD). The facial profile line (FPL) was determined by ultrasonography. The first method (M1) was only used HC to determine whether the fetus was microcephaly, the second one (M2) was to combine HC and FPL for the diagnosis of microcephaly. Results were classified into five orderly categories by experienced sonographers. ROC curve was drawn to evaluate the diagnostic effect.Results: Among the pregnant women, 14 cases of fetal head circumference were less than 3SD, 109 were -2SD < HC≤ -3SD. A total of 12 cases were confirmed of microcephaly by magnetic resonance imaging (MRI) or postnatal, 10 cases of HC were less than 3SD, 2 were -2SD < HC≤ -3SD. The area under the ROC curve for M1 and M2 were 0.751 and 0.983 respectively.Conclusion: The HC in combination with FPL can be used to evaluate the fetal HC and forehead development quickly, and to improve the sensitivity and specificity of diagnosing fetal microcephaly.

Prenatal sonographic characteristics and postnatal outcomes of umbilical-portal-systemic venous shunts under the new in-utero classification: A retrospective study.

An in-utero re-classification of umbilical-portal-systemic venous shunt (UPSVS) has recently been proposed. We retrospectively reviewed the sonograms of a large cohort of fetuses, identified and analyzed UPSVS cases, and presented the prenatal sonographic characteristics, birth outcomes, and follow-up results following the new classification system.Sonograms and clinical data of all participants who visited our departments from April 2016 to July 2018 were retrospectively reviewed. Identified cases of UPSVS were analyzed according to the new classification: Type I: umbilical-systemic shunt (USS); Type II: ductus venosus-systemic shunt (DVSS); Type IIIa: intrahepatic portal-systemic shunt (IHPSS) and Type IIIb: extrahepatic portal-systemic shunt (EHPSS). Postnatal follow-ups ranged from 3 months to 1 year.A total of 10 UPSVS cases were identified in 61,082 fetuses: 4 with Type I, 3 with Type II and 3 with Type IIIa. All 4 cases of USS had complete agenesis of the portal venous system, and had the umbilical vein drained into the inferior vena cava. Two USS cases also had trisomy 21. Pregnancy was terminated in all cases with a Type I shunt. Two fetuses with DVSS had normal portal venous system and were born full term. The pregnancy of 1 DVSS case was terminated due to the detection of trisomy 21. Three cases were IHPSS with full-term birth. One had chromosomal abnormality and 1 had surgery to repair the shunt 12-days post birth. In the 2 cases that did not receive repair surgery, sonographic examination revealed the portal-hepatic venous shunt was not closed at the 6-month follow-up period. However, the 1 case that had repair surgery appeared healthy at the 3-month follow-up period.UPSVS is extremely rare. Type I shunts have the poorest prognosis, and the presence of the intrahepatic portal venous system is key to live birth in UPSVS regardless of types. Chromosomal abnormalities and other organ anomalies can occur in any types of UPSVS. Therefore, karyotyping and examination of other organs should be performed once UPSVS is detected.

Comparison of traditional 2D and 3D Omniview technique in detection of fetus corpus callosum.

AIM: To explore the value of Omniview (OV) technology in assessing the fetus corpus callosum. MATERIAL AND METHODS: For the ultrasound examination of 189 fetuses (gestational week range 19-28 weeks), two-dimensional (2D) ultrasound imaging and Omniview technology were used by two physicians (A and B). The acquisition time and the quality of images were recorded. RESULTS: The acquisition time of Omniview technology was shorter comparing with the aquisition time of 2D ultrasound imaging (A2D vs. AOV: 159.44±27.09 s vs. 73.90±18.99 s, p<0.01; B2D vs. BOV: 120.22±21.89 s vs. 74.19±14.86 seconds, p<0.01). 2D ultrasound examination was performed in a longer time by the junior physician, compared with the senior physician (A2D vs. B2D: 159.44±27.09 s vs. 120.22±21.89 s, p<0.01). The intra- and inter-observer reliability of acquisition time using Omniviewtechnology was good (LoA: ‒11.8 to +12.4s, and ‒41.9 to +43.3s, respectively). The success rate of junior and senior physicians with the Omniview technique was 76.2% and 80.4%, respectively. There was good consistency between the Omniview technique and 2D ultrasound imaging in terms of image quality (Kappa = 0.782, 95% CI: 0.586-0.977). CONCLUSION: Omniview technique can not only obtain corpus callosum images more effectively but also can achieve better quality images. Therefore, it is a reliable method to image the fetal corpus callosum.

Delayed presentation of uterine perforation with ovary migration after dilatation and curettage.

We present a rare but serious uterine perforation. A 31-year-old woman was referred to our department for hyperechogenic mass in uterus on ultrasonography after Dilation and curettage (D&C) for the adherent placenta and retained products of conception. Transvaginal ultrasound examination showed that a mass with several follicles measuring 35×29 mm was seen emanating from the right posterior wall of the uterine cavity, and there was absence of the myometrial tissue. A hysteroscopy and laparoscopy showed a uterine perforation with ovary incarceration. The ovary was rehabilitated, and the uterine perforation site was incised. D&C can not be performed when delayed presentation of uterine perforation with migration of an extrauterine organ is suspected, particularly, some of them are asymptomatic after a difficult intrauterine operation.

Sonographic appearance of the cavum septum pellucidum et vergae in normal fetuses in the second and third trimesters of pregnancy.

BACKGROUND: To characterize the cavum septum pellucidum et vergae (CSPV) in normal fetuses in the second to third trimester. METHODS: The cavum septum pellucidum (CSP) and CSPV were investigated in 322 uncomplicated singleton pregnancies from 25 to 39 weeks' gestation. Visualization rate, width, and morphology of both CSP and cavum vergae (CV) were assessed by ultrasound and MRI. RESULTS: The CSP and CSPV visualization rates were 100% and 7.8% (25/322), respectively. The mean widths were 6.3 ± 1.2 mm (3.4-10 mm) and 6.7 ± 1.0 mm (5.1-9 mm), respectively, with no significant correlation between width and gestational age (r = -0.108, p > 0.05 and r = -0.182, p > 0.05, respectively). In CSPV fetuses, the CV to CSP ratio was 1.004 ± 0.018 (0.967-1.033). All CSPVs were rectangular in the transverse plane and extended posteriorly beyond the midpoint of the brain. CONCLUSIONS: Common features of CSPVs include (1) a rectangular morphology, (2) communication between the two cavities, (3) a CV width within the normal range for CSP, and (4) a CV-CSP ratio of 1. These findings may help distinguish normal from abnormal CSPV.

Embolization of uterine arteriovenous malformation.

BACKGROUND: Uterine arteriovenous malformation is a rare but potential life-threatening source of bleeding. A high index of suspicion and accurate diagnosis of the condition in a timely manor are essential because instrumentation that is often used for other sources of uterine bleeding can be lead to massive hemorrhage. CASE: We describe here a case of uterine arteriovenous malformation. A 32-year-old woman presented abnormal vaginal bleeding following the induced abortion. A diagnosis of uterine arteriovenous malformation made on the basis of Doppler ultrasonraphy was confirmed through pelvic angiography. The embolization of bilateral uterine arteries was performed successfully. CONCLUSION: Uterine arteriovenous malformation should be suspected in patient with abnormal vaginal bleeding, especially who had the past medical history incluing cesarean section, induced abortion, or Dillation and Curethage and so on. Although angiography remains the gold standard, Doppler ultrasonography is also a good noninvasive technique. The transcatheter uterine artery embolization offers a safe and effective treatment.

Different protein profile in amniotic fluid with nervous system malformations by surface-enhanced laser desorption-ionization/time-of-flight mass spectrometry (SELDI-TOF-MS) technology.

AIM: To detect the distinct proteins in amniotic fluid (AF) between nervous system malformations fetuses and normal fetuses. MATERIAL AND METHODS: Surface-enhanced laser desorption-ionization/time-of-flight mass spectrometry was used to characterize AF peptides in AF between nervous system malformations fetuses and normal fetuses. WCX2 protein chips were used to characterize AF peptides in AF. Protein chips were examined in a PBSIIC protein reader, the protein profiling was collected by ProteinChip software version 3.1 (Ciphergen Biosystems, Fremont, CA, USA) and analyzed by Biomarker Wizard software (Ciphergen Biosystems). Nine distinct proteins were identified in AF between nervous system malformations fetuses and normal fetuses. RESULTS: Compared with the control group, three proteins with m/z 4967.5 Da, 5258.0 Da, and 11,717.0 Da were down-regulated, and six proteins with m/z 2540.4 Da, 3107.1 Da, 3396.8 Da, 4590.965 Da, 5589.2 Da and 6429.4 Da up-regulated in nervous system malformations fetuses. CONCLUSION: The results suggest that there are distinct proteins in protein profiling of AF between nervous system malformations fetuses and normal fetuses.

Ultrasound score: a new method to differentiate fetal physiological and pathological hydronephrosis.

OBJECTIVE: To determine whether the prenatal ultrasound (US) score can effectively differentiate fetal physiological and pathological hydronephrosis. STUDY DESIGN: 158 fetuses (198 kidneys) with hydronephrosis (PAPD>or=10mm) were diagnosed by prenatal US in the third trimester. We measured and recorded three US parameters: renal pelvic anterior posterior diameter (PAPD), renal parenchyma thickness and pelvicaliceal morphology. They were graded with a score from 0 to 3 on the basis of severity of hydronephrosis, and the total US score of each kidney was obtained. According to the postnatal US and clinical diagnosis and management, all the cases were divided into two groups: physiological and pathological hydronephrosis. Using receiver operating characteristic curves analysis, we researched whether the US score was more accurate than each parameter and which was the best cut-off value for differential diagnosis of physiological and pathological hydronephrosis. RESULTS: Of all the 198 hydronephrosis, 139 (70.20%) were physiological and 59 (29.80%) were pathological confirmed postnatally. Area under the curve of US score was 0.982, which was significantly larger than that of each parameter (P<0.05). The higher the score, the higher the possibility of pathological hydronephrosis was. Score 6 was the best cut-off value: the sensitivity, specificity, positive predictive value, negative predictive value, consistency rate and Youden's index were 89.83%, 94.24%, 86.89%, 95.62%, 92.93% and 0.8407, respectively. CONCLUSION: Prenatal US score is easy to obtain by measuring some data of the kidney and can effectively differentiate fetal physiological and pathological hydronephrosis. It can also be used as a new quantitative method to evaluate the prognosis of fetal hydronephrosis so as to provide reference for prenatal intervention and more accurate information for the family of the fetus.