Are Abnormal Yolk Sac Characteristics Important Factors in Abortion Rates?

Abstract

Background

This study was undertaken to determine if there were different miscarriage rates between normal and abnormal yolk sauk .

Materials and Methods

In this cohort report, the egg yolk theca characteristics of 193 consecutive pregnant women, of 5-6.5 weeks pregnancy, with normal body mass exponent ( BMI ) were prospectively evaluated. All patients undergo two-dimensional transvaginal sonography, which was performed by the same sonographer. We considered the postdate egg yolk sac characteristics as convention for classification : diameter : 2-5 millimeter ; round of golf human body ; absence of degenerative changes ; equal issue with embryo ; echogenic flange and hypoechoic center. Yolk theca that had diameters smaller than 2 millimeter or larger than 5 millimeter ; a condition that was not round ( i.e., oval or distorted ) ; the presence of degenerative changes ; hyper- or hypo-echogenic rim ; hyperechoic center and inadequate issue with embryos were considered abnormal. Based on the above classification, patients were divided into two groups, report ( abnormal yolk sac ) and command ( normal yolk sac ). The study group contained 22 cases and the command group consisted of 164 cases. The basal consequence measure was the abortion rate between both groups. Chi-square and students ’ triiodothyronine test were used for data analysis .

Results

A sum of 193 cases were evaluated. We excluded 2 cases. Among the remaining 191 cases, 22 ( 11.51 % ) had abnormal yolk sac of which spontaneous abortion occurred in 14 ( 63.63 % ) cases. In the control group, out of 169 ( 89.49 % ) cases, spontaneous abortion was noted in 6 ( 3.55 % ). There was a statistically significant remainder in abortion rates between the two groups ( p=0.000 ).

Conclusion

According to the results of this sketch, it is obvious that abnormal egg yolk theca characteristics are associated with ad-lib miscarriage. Keywords:

Yolk Sac, Spontaneous Abortion, Abnormal

Introduction

The inaugural recognizable structure inside the gestational sac is the egg yolk theca, which should be detectable as a regularly rounded extra-amniotic structure when the gestational pouch reaches dimensions of 8 to 10 millimeter. The convention biometric rate of the yolk pouch diameter during the first trimester should be an inner diameter of 3-6 millimeter. spontaneous miscarriage has been noted to occur in cases with no egg yolk theca, a yolk sac with dimensions over 6 mm or under 3 millimeter, an irregular form ( chiefly wrinkled with indent walls ), the presence of degenerative changes such as numerous calcifications that have decreased translucence of the egg yolk pouch and the yolk pouch number, which should be the same as the number of embryo as visualized by 2-D ultrasound ( 1 ). In a normal pregnancy it should be possible to observe the yolk pouch between 5-12 weeks of pregnancy or when it reaches 10 millimeter in size. Abnormal morphologic appearance of the yolk pouch and/or a size over 9 millimeter is indicative of unplayful increase disorders of the fetus ( 2 ). ad-lib abortion rates are significantly elevated in cases where the egg yolk sac book falls outside the 5th to 95th percentile ( 3 ). Yolk sauk diameters over 5.6 mm and the presence of an abnormal yolk sauk supreme headquarters allied powers europe visualized at initial sonography are associated with hapless pregnancy result ( 4 ). Pregnancies that have a mean yolk theca diameter adequate or larger than 5 millimeter on early ultrasound are besides associated with a threefold increased hazard for first trimester loss, mugwump of maternal risk factors such as historic period, consistency mass index, polycystic ovary syndrome, smoke, and diabetes ( 5 ). The lack of a egg yolk pouch or a smaller than gestational age egg yolk pouch diameter are indicative mood of pregnancies that may result in ad-lib abortion ( 6 ). Pregnancies with a very large yolk sauk are broadly always associated with inadequate outcomes ( 7 ). This learn was undertaken to determine if there were different abortion rates between normal and abnormal yolk sauk .

Materials and Methods

This study was a cohort survey carried out on 193 fraught women who were between 5-6.5 weeks of gestation and with a body mass index ( BMI ) between 18-24. Patients were seen in Amir University Hospital, Semnan, Iran during May 2009 to May 2010. The method of sampling was convenient. Written informed consent was obtained from all patients. This study was approved by the Ethical Committee of Semnan University of Medical Sciences. The follow patients were excluded : those whose gestational age was more than 6.5 weeks, patients with diabetes, high blood pressure, or any systemic disease, those who expressed unwillingness to come for follow up visits, and know cases of Mϋllerian anomalies. We performed planar transvaginal sonography on 191 consecutive fraught cases that were between 5-6.5 weeks of pregnancy, as character of the routine evaluation or other reading for sonography. The size of the yolk sauk ( inner to inner diameter ), human body, echogenicity of brim and concentrate of sac, numbers of egg yolk sauk and degenerative changes such as calcification were evaluated. For all cases, the planar transvaginal sonography was performed by the same sonographer. Yolk sauk that had the comply characteristics were classified as convention : diameter between 2-5 millimeter, attack determine, absence of degenerative changes, peer act with embryo, the presence of an echogenic rim and hypo-echoic center. Yolk sac that had diameters smaller than 2 millimeter or larger than 5 mm, were not round ( i.e., oval or distorted ), had evidence of degenerative changes, hyper- or hypoechogenic rim, hyperechoic center, and inadequate count with embryos were considered abnormal. Based on the above mentioned criteria patients were divided into two groups, study ( abnormal yolk sac ) and control ( normal yolk sac ). All cases were followed until delivery and the abortion rates ( delivery before 20 weeks of pregnancy ) were compared between the groups. Data were expressed as percentage and compared using the chi-square and students ’ thymine tests. statistical analyses were performed with the statistical box for Social Sciences ( SPSS, translation 16.0 ) .

Results

The base age of the study group was 28.1 ± 5.8 years and that of the see group was 28 ± 4.8 years, which was not statistically significant ( p=0.876 ). During the study time period a total of 193 cases were evaluated. There were two cases who did not return for their surveil up visits, therefore we excluded them from the learn. Out of 191 cases that were evaluated, 22 ( 11.51 % ) had abnormal yolk sauk of which spontaneous abortion occurred in 14 ( 63.63 % ). The control group consisted of 169 cases. Of these, spontaneous miscarriage occurred in 6 ( 3.55 % ). There was a statistically significant dispute in miscarriage rates between the two groups ( p=0.000 ). With regards to abnormal egg yolk theca characteristics, 11 ( 50 % ) had yolk sauk that were greater than 5 millimeter ; the largest was 9.2 millimeter in a patient who had four perennial abortions ( ). ad-lib miscarriage occurred 10 ( 45.45 % ) who were between 6-8 weeks of pregnancy. The largest egg yolk sauk with a convention, uneventful pregnancy was 6.6 millimeter in diameter ( ).

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Table 1

CharacteristicsNumber (%)Abortion ratesSize (>5 mm)11 (50)10 (45.45)Distorted shape4(18.18)2(9.9)Hypo-echoic rim4(18.18)1(4.54)Two-yolk sac1(4.54)0No yolk sac1(4.54)1(4.54)Oval shape1 (4.54)0Open in a separate window Four ( 18.18 % ) had distorted yolk shape with spontaneous miscarriage in 2 ( 9.90 % ) who were between 6-8 weeks of pregnancy ( ). however the other 2 ( 9.90 % ) continued their pregnancies to term with normal, alive births ( ) .Open in a separate window One ( 4.54 % ) lawsuit had two yolks, however her pregnancy was uneventful. In 1 ( 4.54 % ) lawsuit, no yolk sac was present and a spontaneous abortion occurred at nine weeks of pregnancy ( ). One ( 4.54 % ) sheath had two yolks, however her pregnancy was uneventful. In 1 ( 4.54 % ) case, no yolk theca was salute and a ad-lib miscarriage occurred at nine weeks of pregnancy ( ). In 4 ( 18.18 % ) patients, the egg yolk pouch had hypo-echoic rims ; all had long-run bleeding during the first spare of pregnancy which was stopped by the manipulation of progesterone preparations. With the exception of one miscarriage at seven weeks of pregnancy, the remaining pregnancies continued to condition. In one case of this group, the pregnancy was terminated at 34 weeks because of oligohydramnios, but the fetus was normal and had no problems after rescue ( ). In the dominance group, abortion occurred in 6 ( 3.55 % ) cases. Pregnancy continued to condition in the remaining control cases ( n=163 ; 96.44 % ). Preterm delivery occurred in 7 control patients ; however all were more than 33 weeks fraught. Of these, all neonates survived. With regards to yolk theca characteristics of the master group, the sauk diameters ranged from 2-4.9 millimeter, all of which had a round shape .

Discussion

The egg yolk sauk is the first structure of the gestational theca, which must be portray when the intend gestational theca diameter is 13 millimeter or smaller in size ( 8 ). It is recommended in a affected role at risk for hapless pregnancy consequence to assess the egg yolk sauk measurements anterior to 12 weeks of pregnancy by transvaginal sonography and repeat the appraisal one to two weeks later when a discrepancy is detected in the inaugural shipshape ( 9, 10 ). In this cogitation we evaluated the characteristics of the first significant structure of the gestational theca and its relation back to the spontaneous miscarriage rate. Pregnancies that have a mean yolk sac diameter peer or larger than 5 millimeter as visualized on early sonography are associated with a double increased gamble of first spare loss ( 5 ). visual image of a big size egg yolk sauk is a predictor of poor pregnancy result ( 11, 12 ). In agreement with the above studies, the results of this study showed that yolk size was an significant component for prediction of spontaneous miscarriage. Yolk sacs larger than 5 mm at 5-6.5 weeks of pregnancy were a good indication that the probability of abortion was importantly high. however, a very large yolk sac may exist in convention pregnancy and the presence of a yolk sac with a diameter of 8.1 mm in a feasible pregnancy has been reported ( 13 ). In this study the largest yolk sauk with a normal pregnancy result was 6.6 millimeter. Larger yolk sac diameters may represent attest of certain diseases and the pregnancy passing in these pregnancies is reflective of the presence of such underlie diseases. According to Ivanisević et alabama. in their study the researchers confirmed the presence of larger egg yolk theca diameters amongst type 1 diabetic women who were complete six weeks of gestation ( 14 ). Abnormal yolk sac shape are associated with abnormal pregnancy result with a sensitivity of 29 %, specificity of 95 %, cocksure predictive rate of 47 % and veto predictive rate 90.5 % ( 4, 15 ). identification of abnormal yolk pouch may suggest the death of one or all embryo ( 16 ). The current study showed that among 4 ( 18.18 % ) cases with tinge egg yolk theca ad-lib abortion happened in 2 ( 9.90 % ). however the remaining 2 ( 9.90 % ) cases with egg-shaped egg yolk sauk had normal pregnancies. failure to detect the presence of a yolk theca before the detection of an embryo in the first tailored by sonography is suggestive of an abnormal intrauterine pregnancy ( 17 ). In this study there was one ( 4.54 % ) case that had no egg yolk pouch in the eighth week of pregnancy. This character aborted the fetus after one workweek. normally there is one egg yolk sauk in a unmarried pregnancy and the number of theca must equal the issue of embryo. During the first trimester of a dichorionic counterpart pregnancy the yolk sauk are always separated by a septum. They are not separated in a monochorionic match pregnancy ( 11 ). In this study there was one ( 4.54 % ) subject which had one embryo and two egg yolk pouch, whose pregnancy had a normal result. normally a normal egg yolk pouch has an echogenic flange and hypoechoic center. In the current learn there were 4 ( 18.18 % ) with hypoechoic rims, all experienced hanker term shed blood in the beginning trimester, however only one case had an miscarriage. It was probable that this detail characteristic of the yolk sac was not an important factor for an miscarriage.

Conclusion

We have concluded that abnormal egg yolk theca characteristics are associated with spontaneous miscarriage. In this report abortion occurred in 90.9 % of cases where the yolk theca was of an abnormal size and in 50 % of those with twist shape yolk theca. thus, it is presumed that among the egg yolk sac characteristics, a large-size egg yolk and deformed determine are the most important factors for early pregnancy loss. evaluation of the importance of other criteria needs extra studies with larger numbers of cases .

Acknowledgments

The authors express their taste to the nursing staff of the Department of Radiology at Amir University Hospital.The authors state of matter they have received no fiscal patronize by any organization and there is no conflict of sake for this report .