| Background and Objection:Twin pregnancy happens about 1/90.70% twin pregnancy are double egg twins, they are fertilized by two eggs.30% twin pregnancy are one egg twins, they divide from one cell. In all human beings, twin pregnancy from one egg happens nearly the same; it’s about 3-5/1000. But twin pregnancy from double egg can be divided from the features of chorine, the number of placenta and the features of amnion. The type of double egg twins will be different according to the time of spermatovum happens: before morula (three days after fertilizing) DCDA; in blastula stage(4-7days after fertilizing)MCDA; after amnion formed(8 days after fertilizing)MCMA. this type happens seldom. But if it happens after the original placenta formed, it will become Siamese twins. The two placenta of one egg twin use the same blood, if one baby die, the other will have dangerous and it will also affect the Clotting mechanism of pregnancy women.Twins of monochorionic happens 1/250 in natural pregnancy. In recent years, the assisted reproductive technology and stimulate ovulation drugs make the MC twins increase every year, nearly 2-12times more than natural pregnancy. MC twins will have more disease and die easily, so if we don’t do something, the mortality will be double than DC twins and 4times higher than having single baby; and the MC twins will have more chance to have mental disease, nearly 4-5times than DC twins and 25-30times than single baby. MC twins belongs to high risk pregnancy, women will have more disease during pregnancy time, such as:Gestational hypertension disease, gestational diabetes, pregnancy cholestasis, premature rupture of membranes, placenta previa,etc; and some other disease which will happen only in the twin pregnancy women, such as:twin-to-twin transfusion syndrome, TTTs、selective intrauterine growth restriction, SIUGR、 twin reversed arterial perfusion sequence, TRAPS,etc。Selective intrauterine growth restriction of monochorionic diamniotic is the most common disease in monochorionic diamniotic. It will not only affect the growth of fetus, but also affect their angiocarpy and internal secretion after they are born. But we are still unknow about the reason and the action.Standardized treatment and has yet to form a consensus, so the problem becom es the focus of current research on complexity of twin pregnancy.The definition of Selective intrauterine growth restriction of monochorionic diamniotic is still undecided. Some researchers think:MC twins, the weight difference of two babies (the weight of the big baby-the weight of the small baby) is more than 25% can be diagnosed SIUGR. But Gratacos standard is more well used:in MC twins, if one estimative weight by ultrasonic testing is less than 10% of the pregnancy time, it can be decided MC twin pregnancy, MCDA SIUGR. In MC twins, if one weight is less than 10% of standard weight, nearly 95% twins will have quality different. The reason is complex, it affect by the 3 basic reasons:placental vascular anastomosis、 the placenta sharing degree and each share into quality of placenta。Vascular casting technique use the biology vascular pipe as mode, with the help of some pressure to fill the vascular with material resistant to strong acid or alkali corrosion to make the vascular full. After the material becoming solid, put them into strong acid or alkali corrosion, making the other organization corrosion, only keep the vascular organization, so it can clearly reflect the vascular’s running and diameter; branches of artery and vein and the form of vasoganglion. Placenta vascular casting technique is the most common used ways to research and observe the form of placenta’s vasoganglion, it use the pipe technique to rebuild the placenta’s blood vessel, so we can see the form of blood vessel clearly. SIUGR vascular casts can help us understand the placenta of placentalvascular anasto mosis and classification changes in vessel diameter featuresto further study the patho genesis; but also for intrauterine treatment ofsurgery and prognosis of surgery provides a Visual evaluation.Gene imprinting, also called genetic imprinting or parental imprinting, is a phenomenon which has been discovered recently that pass some genetic information only rely on one single parent. It refers to apair alleles which control a certain traits will have different expression because of different close, it only express one single parent gene. According to the source, it can be divide into two kinds:one is mother source imprinted genes, so father source genes is inactive, such as ASCL2/HASH2、 H19、 CDKN1C、Mash-2、 PHLD A2,etc; the other is father source imprinted genes, so mother source genes is inactive, such as PEG3、 IFG2、 ZnF127、 X1AS、 SNRPN、 IPW,etc. Father expr ess can promote fetus growth and nutrient absorption; mother express will rest rain fetus growth. All of this can cause fetus growthabnormal.IGF2 is father source imprinted genes, some research express:If IGF2 express too much, it will make the fetus grow too quickly or make the placenta too big; but if it is absent or too slow, it will restrain the fetus and placenta growth. Sibley and some other researchers observe.-the reduce of IGF2 will make the volume of placental lobule reduce, improve the development of placenta material exchange, there is some relevance between the IGF2 abnormal and the weight of new born baby, so IGF2 maybe the main reason that cause the fetus growth restrain in the placenta.PHLDA2 genes, in llpl5.5, mainly express in the placenta, its level and the quality of new born baby are in a negative correlation. If we over express the restrain of growth cell and sponge nourish cells in the mice, it can increase the birth weight, if they don’have the genes, they will grow quickly.This study see the placenta of MC twin pregnancy women as the research object, use the placenta vascular cast technique and placenta vascular structure and line characteristics to do the three-dimensional reconstruction.And immunoh istochemical methods discussed paternal imprint on the growthinhibition of PHLDA2 (pleckstrin homology-like domain fmily member 2) andmaternal imprintin g of IGF2 growth-promoting genes (insulin-like growthfactor 2) expression in the placenta; While using the ELISA method of comparing normal monochorionic twin pregnancies, and patients with sIUGR cord blood and serum expression of imprinted genes in the two groups and looks forward to exploring monochorionic twin sacs sIUGR mechanisms may occur.Chapter one relative research of different twins and the reasons of fetus growth restrainobjective:Twins pregnancy can cause a lot of disease, especially MC twin pregnancy, the prenatal infant will have many disease and have high mortality rate. According to analysis and compare of the twin pregnancy, especially pregnant woman and puerpera’s situation and complication and baby’s situation; we hope we can find the reason which cause the fetus growth restrain of MC twin pregnancy. So we can provide some reference for the prenatal health care, complication prevention and prenatal outcome.Methods:According to the 460 MC and DC twin pregnancy women who delivered in Nanfang Hospital of Southern Medical University from Jan.2013 to Jun.2015, we divide them into MC group and DC group, we compare the basic information of pregnancy women、complications、baby’ situation of these two group. In order to find the relations with SIUGR, we also analysis the age of pregnancy women、 maternal time、fertilization way、 delivery time、 delivery way、 Gestational hypertension and gestational diabetes. We want to find the reason which cause selective intrauterine growth restriction in this two group.We have decided their type through ultrasound. Ultrasound diagnosis:pregnancy 6-9weeks, we can decide according to the number of pregnant bursa, pregnancy 10-14weeks, we can decide according to the form. MC twin pregnancy will be T form; DC twin pregnancy will be diagnosis.Results:The number of babies who are delivered in Southern Medical University Nanfang hospital from Jan.2013 to Jun.2015 is 9948, among them 564 are twin pregnancy and 460 are twin pregnancy are in the research. We divide the m into two group:MC group (140 people, nearly 30% of the whole) and DC group (320 people, nearly 69.5% of the whole). Compare the basic situation of pregnancy women and maternal women, there is great difference in women’s age, ways of pregnancy and ways of delivery, and it has statistic meaning (P<0.05); there is little difference in times of pregnancy, times of delivery, and if they stay in the hospital when they are pregnancy, if it’s the her first baby and if they have abortion (P>0.05).Compare the complicatios when they are pregnancy between this two group:there is no difference in Hypertensive disorders in pregnancy, gestational diabetes, ICP, lateabortions, premature rupture of membranes, preterm labor, anemia and Placental Abruptin, placenta previa, twin-twin transfusion syndrome,anemia-Polycythemia in twin pregna ncy, postpartum hemorrhage (P>0.05), And there is also great difference in Preterm premature rupture of membranes, selective fetal growth restriction, it has statistic meaning (P<0.05); compare the situation of the babies:there is no great difference in the weight of the babies, the length of the babies(big ands mall), The risk change one’s major cases of newborn babies, neonatal asphyxia and fetal abnormalities (P>0.05)Selective restricted fetus as dependent variable, age, way of conception, pregnancy, childbirth, gestational age, gestational hypertension, gestational diabetes, chorion nature, newborn body weight, body length, asphyxia rate as independent variables to the selective high risk factors of fetal growth restriction multiariable Logistic regression analysis.The result shows:the birth gestational age and birth weight to risk factors.Conclusion:1、MC and DC pregnancy will have important influence of the process and result of maternal pregnancy, MC twin pregnancy is lower than DC twin pregnancy in delivery week, age of women and weight of baby (P<0.05);2、 It has no effect to complications, but MC twin pregnancy has a higher rate in fetus growth restrain than DC(P<0.05). It has no effect to the pregnancy women, mainly to the babies.3、 So we can see the importance for pregnancy women knowing if they have high risk with the help of the ultrasound. And they must keep checking by the ultrasound. It has great importance in strengthen the monitoring, clinical consultation and intervention treatment.Chapter two Placental vascular cast model and its morphology of the growth restrain baby of the MC twin pregnancy womenObjective:Set up Placental vascular cast model of MC twin pregnancy, and Discuss placental vascular morphological changes and clinical significance of MC twin pregnancy.Methods:1. Research objective:the specimen comes from women who delivery in Nanfang hospital of Southern Medical University from Jan.2014 to Jun.2015.10 specimen from the MC twin pregnancy who have SIUGR; 10 specimen from MC pregnancy who are normal. SIUGR Diagnostic criteria:MC twin pregnancy, the weight of any baby is 10% less than normal can be diagnosed.2. ways:placenta after treatment, soak in 95% alcohol for 15 minutes, Separate 2 arteries and 1 vein, put pipes separately, seal the bottle by pushing injection with water, put Self-curing denture acrylic 30g, Self-curing denture palate water 60ml, paints oil into the pipe, first into the veins, then into the arteries. One after one, until they are full. Until they are all finished, ligate the the vein and arteries. Put them into the 20% concentrated hydrochloric acid after they are solid. For nearly 3-5d, take them out and wash, then we can take the information. The research targets include: ① The placenta weight and volume;② After placental vascular cast, Measurement with vascular anastomosis and placental arteries and veins at all levels within the vascular lumen diameter indicators, and keep image information;③ compare Maternal placental vascular morphological differences between MC twin pregnancy which have selective intrauterine growth restriction(A group) and MC twin pregnancy which are normal (B group).Results:1.Compare the puerperal situation of two group:SIUGR (A group):age of pregnancy women is from 20～37, average age is (28.36±4.79), babies are born in 28+4～37+6 weeks, average time is 35.10±2.69 weeks; the normal group B group:age of pregnancy women is from 23～38, average age is 31.04±5.13, babies are born in 35+1～39+3 weeks, average week is 35.32±2.66 weeks. In SIUGR (A group) share rate of two placenta> 1.5, much higher than group B. Among the 10 placenta MC twin pregnancy women who have SIUGR,6 has Abnormal umbilical cord of attachment, The racket shape or sail the placenta; but among the 10 placenta of MC twin pregnancy women who are normal, only 1 has Abnormal umbilical cord of attachment.2. In SIUGR (A group) two babies has a lot of Vascular anastomosis branch, including vein-vein Vascular anastomosis branch and artery-artery Vascular anastomosis branch. And it also has vein-vein Vascular anastomosis branch and artery-artery Vascular anastomosis branch in down deep lobular capillary level. The two babies has great difference in The vascular tube diameter of all kind of veins and arteries.3. In normal group (B group), vein-vein Vascular anastomosis branch and artery-artery Vascular anastomosis branch seldom happen. The two babies has less difference in The vascular tube diameter of all kind of veins and arteries. The result has statistical meaning. (P< 0.01);Conclusion:The three factors which affect the growth of MC twin:Placental vascular anastomosis, The placenta sharing degree and Each share into quality of placenta. The MC twin placental share, and vascular anastomosis will affect the final blood share of the twin. On the one way, it has the effect of compensatory and protection, Move-artery anastomosis of Larger diameter will make the nutrition and oxygen moving from the big baby from the small one because of the pressure. So it will balance the pressure of blood between two babies, it can make the difference of the two babies’ weight less than the placenta uneven share. If it has no this match, twins uneven weight difference degree and placenta share the same degree. On the other hand, it has harmful effect. Although the existence of move-artery anastomosis can slow the slow the growth of two babies in some way. But it the small baby die, the big one will still move the blood and nutrition to the small baby because of the pressure. It can make the big baby die or make his brain lack blood.Chapter three The difference of PHLDA2、IGF-2 of baby growth restrain in MC twin pregnancyObjective:By using the ways of immune and ELISA to find the difference of PHLDA2 and IGF2 of MC twin pregnancy women who have SIUGR, and find the connection.Methods:1. Immune way:collect 20 specimen of placenta from MC twin pregnancy women who have SIUGR,10 big and 10 small. Using immunohistochemical S-P method to detect PHLDA2 and IGF2 protein expression in two groups of specimens.2. ELISA way:collect 10 Umbilical cord blood specimens of MC twin pregnancy women. The two groups of maternal serum ELISA experiment testing and two groups of fetal umbilical cord blood PHLDA2 and IGF2 protein expression differences.Results:1.Comparison of two groups:monochorionic twin pregnancies complicated sIUGR maternal Group (group A) and monochorionic twin Group (Group B):① onmaternal age difference statistically significant (P<0.01) second merge sIUGR maternal gestational weeks earlier than normal twin Group (P<0.05) Merge slUGR two maternal fetal birth weight differences (P<0.01) about complicated slUGR maternal Group (group a) two fetuses were born poor healthwas significantly greater than thatin the control group (P<0.01).2. immunohistochemical results:Immune way:among the specimen of MC twin pregnancy women who have SIUGR, the small placenta have higher level of PHLDA2 than the big one, but they have lower level of IGF2 (P<0.01);1) localization and distribution of IGF-2 inplacenta:placenta of normal monochorionic twin fetuses in pregnant women (bgroup) Organization-positive cells, mainly for the syncytiotrophoblast andcytotrophoblasts tomentose leaflets, also can be found in the amniotic membrane tomentum. IGF2 coarse, diffuse distribution in a cell, located in the Cytosolic and matrix. Cells are higher than the yellowish-brown or dark-brown background. Monochorionic twin pregnancies complicated slUGR maternal(group a), fetus (A1) IGF2 slightly reduced number of positive cells thannormal pregnancy, staining slightly diminished; little fetus (A2) IGF2 significantly reduced number of positive cells than normal pregnancy,staining decreased significantly.2) PHLDA2 reading results:normalmonochorionic twin pregnancies in two (Group b) in the placenta, the cellscolorless, or occasionaly yellow. Monochorionic twin pregnanciescomplicated sIUGR maternal (group a), fetus (A1) PHLDA2 slightly increasednumber of positive cells than normal pregnanc y, dyeing is a light yellow orcolorless; little fetus (A2) PHLDA2 increased number of positive cells thannormal pregnancy, stain significantly enhanced, Brown or yellowish-brown to change.3. ELISA experiment results:1) single chorionic double amniotic membrane SAC double tire merged sIUGR maternal two fetal umbilical blood between IGF2, and PHLDA2 expression level exists obviously differences, IGF 2 in small fetal (A2) umbilical blood in the of expression level significantly below big fetal (A1); and PHLDA2 in small fetal (A2) umbilicalblood in the of expression level significantly above big fetal (A1); two group between compared differences significantly (P<0.05).2) normal single chorionic double amniotic membrane SAC double tire maternal two fetal umbilical blood between IGF2, and PHLDA2 expression level exists differences smaller; two group between compared differences no statistics meaning (P>0.05); 3) single chorionic double amniotic membrane SAC double tire merged sIUGR (A, group) and normal single chorionic double amniotic membrane SAC double tire(B group) Maternal serum in the IGF2, and PHLDA2 expression level also exists obviously differences, IGF2 sIUGR (group a), maternal serum levelssignific antly lower than the normal expression in monochorionic twinamniotic sac twins (B) maternal and PHLDA2 merge sIUGR (group A) expressionof maternal serum levels were significantly higher than normal monochorionictwin amniotic sac twins (Group B), significant difference between two groups(P<0.01).Conclusion:The PHLDA2 and IGF2 express abnormal among the MC twin pregnancy women who have sIUGR. It can restrain baby growth by affecting the placenta growth and the nutrition supply. |
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