Thursday 6 March 2008

Multiple Pregnancy

Multiple Pregnancy
[Summary]



A pregnancy at the same time two or more of the fetus, known as multiple pregnancy. Multiple Pregnancy of pregnancy, childbirth complications, perinatal mortality, neonatal mortality, it is a high-risk pregnancy. To improve the outcome of pregnancy, in addition to early diagnosis, should be strengthened and the importance of prenatal care during delivery address.



[Diagnosis]




According to history, obstetric examination, the diagnosis of multiple pregnancy it is not difficult to establish, doubt aided by B-mode ultrasonography, and other examinations.

1. History: The two sides have child labor in the family history of the pregnancy before ovulation drug therapy; early reaction heavier entry after the second trimester, weight gain, abdominal discomfort for expansion.

2. Obstetric inspection

(1) uterine volume significantly greater than the corresponding gestational age.

(2) hit more than three or fetal pole; fetal head smaller, and uterine volume disproportionate; fetal limbs, many located in the uterine cavity.

(3) in the womb and heard different parts of the frequency difference of 10 beats / min over fetal heart tone, or of the fetal heart rate although almost, but the interval between cardiac fetal heart tone with a sound district.

3. Auxiliary

(1) B-mode ultrasound examination: is the diagnosis of multiple pregnancy the most important method. Application of B-mode ultrasonography for abdominal imaging examination, as early as six weeks pregnant when implantation in the uterus to display different parts of the number of embryo sac, each embryo sac with a double loop around the decidual characteristics of the components Liquid ring. 7 to pregnant weekend, the germ within a rhythm of the heart beat of the original. After 12 weeks of pregnancy, fetal head imaging, the detection of the fetal head of the biparietal diameter. With the growth of gestational age, diagnostic accuracy rate of 100%. Therefore, suspected of multiple pregnancy, should continue to follow-up, the number of fully established until the fetus.

(2) Doppler sonography: After 12 weeks pregnant after using fetal Doppler frequency preference can not hear the fetal heart tone.

(3) Determination of serum alpha-fetoprotein: also help in the diagnosis of multiple pregnancy. Twin pregnancy, 29.3% was significantly higher serum alpha-fetoprotein; three children, 44.8%; four children and four children or more, up 80.0 percent. Therefore, maternal serum alpha-fetoprotein screening unusual increase in value, suggested that multiple births may need further examination.

B-twin pregnancy diagnosis choriocarcinoma, the following steps can be followed: ① such as placenta see two for the dual-chorionic; ② If only one placenta, fetal decision each of the sex, the opposite sex for dual-chorionic pregnancy; ③ If the same sex twins, carefully scanning the divide, 4 for dual-layer sure chorionic double amniotic membrane, 2 pairs of a single human chorionic amniotic membrane. After entering the mid-pregnancy through the Series B-monitoring, if found: ① two fetal development inconsistency, poor fetal biparietal diameter> 5 mm or head circumference difference> 5% difference abdominal circumference> 20 mm; ② sheep significant differences in water; ③ in a fetal edema, can be made in the diagnosis of chronic transfusion syndrome.


[Treatment]




Dealing with pregnancy

1. Prenatal care: diagnosed as multiple gestation, the nutritional status of pregnant women should be in accordance with the proposed adjustment menus to increase calories, protein, minerals, vitamins and fatty acid intake of the need for the principle of appropriate and added iron and folic acid. After the second trimester, told more than bed rest may increase uterine blood flow increased fetal weight; reduce cervical bear intrauterine pressure to reduce the incidence of premature delivery. Strengthen prenatal examinations in order to facilitate early detection and timely treatment of complications, such as anemia, pregnancy-induced hypertension; series of monitoring fetal growth and placental function. Twin pregnant women 35 to 36 gestational weeks in the hospital, three children and pregnant women above many pregnancies, second trimester that bed rest and hospitalization, as appropriate, the amount of application of contractions, selective implementation of cervical cerclage; late pregnancy Application adrenal cortex hormones promote fetal lung maturity.

2. Twins deal with the death of one of intrauterine: In the current widely used B-checks to perinatal care of the situation, combined with clinical manifestations, one of the twins died of intrauterine diagnosis is not difficult. As to whether or not need to be addressed will depend on the time confirmed. If one of the fetuses died in early pregnancy, stillbirth all can be absorbed without taking measures. Pregnant three months after the death of the fetus, because the trunk has not fully ossification, tissues and organs in the water and amniotic fluid have been gradually absorbed, no need to adopt measures. Pregnant three months after the death of the fetus, because the trunk has not fully ossification, tissues and organs in the water and amniotic fluid have been gradually absorbed, and can be left on the mummy of the fetal membranes may also be live births from pattern-variable compression fetus. One of the twins died in the second trimester after the crux of the custody deal with the continued survival of fetal growth and development, sheep water, placental function, as well as monitoring of maternal blood coagulation, primarily the concentration of plasma fibrinogen, prothrombin time and clay activated partial thromboplastin time, platelet count and the amount of fibrin degradation products, with pregnancy-induced hypertension, in particular should pay attention to. Fibrinogen the formation in the liver, normal liver, plasma fibrinogen level of consumption reflects the decline. Chronic disseminated intravascular coagulation, can be achieved by attrition and generate dynamic balance and fell fibrinogen not obvious. If another good fetal growth and development to continue, Maternal plasma fibrinogen level of stability, can continue to observe. In the process, once the plasma fibrinogen levels to 2.0 g / L (200mg/dl) or the estimated survival after birth can be induced labor timely termination of pregnancy. Labor should be prepared blood fibrinogen to prevent postpartum hemorrhage. If the gestational age <34 weeks, to improve the survival rate of fetuses may consider the application of small-dose heparin treatment. Heparin can be activated coagulation confrontation, prevent prothrombin into thrombin; to combat the role of thrombin, and to prevent platelet aggregation and destruction. As larger, and heparin through the placenta, it will not be applied to pregnant women affected live births coagulation function. 100 mg/24h general dose, intravenous medicine during in vitro coagulation time indicators guardianship, maintained at about 20 minutes. Application of heparin usually 24 to 28 hours, enough to plasma fibrinogen levels picked up again and then, as appropriate reduction, timely induction.

Fetal blood transfusion exists between the best treatment is to eliminate placental vascular anastomosis. Application of the fetal-placental vascular anastomosis find them forceps or laser intravascular coagulation of blood with broken overcast transfer experiment has been successful, can be used for clinical soon. At present, only a fetal blood transfusion, in the B-under the guidance of mother-fetal abdominal wall puncture or umbilical vein blood transfusion or through the mirror for fetal umbilical arterial blood transfusion. In the development and severity of the illness before the balance of fetal maturity, timely termination of pregnancy. Severe twin transfusion syndrome in the inevitable consequences of the situation, also advocated selective fetal reduction, with a view to another fetus can survive.

Born after treatment, in exchange for the effective volume of blood transfusion. Feeding infants severe anemia, the blood hematocrit infants> 0.75, can exchange transfusion. According hematocrit decision blood transfusion. By blood infants shake, 10 to 15 ml / kg, imported plasma or 5% glucose solution to reduce blood viscosity and improve microcirculation. Red blood protein infants <130 g / L, blood transfusion should be.

4 In order to avoid the high number of multi-fetal pregnancies to improve pregnancy success rate, many foreign scholars advocated early pregnancy selective fetal reduction and development in order to reduce the number of embryos, multifetal pregnancy into twin pregnancy, childbirth can achieve purposes, but also to eliminate the number of high-fetal pregnancies, the return of the crisis and poor prognosis. Taken by the two current methods of operation, are under the guidance of B-scan:

(1) abdominal: Select mirror close to the wall, the highest occupied intrauterine fetal sac, transabdominal into the fetal sac, and fetal pleural or fetal heart, injection of 5% NaCl 3ml or 15% KCl 2ml, embryonic cardiac arrest .

(2) the vagina: Select the fetal sac near vaginal probe, the vaginal fornix puncture uterine wall re-enter the fetal sac, and fetal chest, injecting 15% kCl 2ml; or needle through the catheter and 20 ml syringes connected penetrate fetal sac , the needle close to the embryo, and then suddenly aspiration leading to fetal cardiac arrest.

However, the number of high-fetal pregnancy in the first trimester whether it is appropriate for selective fetal reduction, there are still urgent discussion. Some scholars believe that the significance of little habitation formed after complete abortion, its subsequent negative remedy, as prior positive prevention, was called: ① master ovulation drug dose, especially HMG to avoid over-stimulate the ovary; ② reduce a transplant gametes, embryos number.

Treatment delivery

1. Mode of delivery options: on the mode of delivery of the twins, on the onset of labor when exposed to gestational age and fetal portfolio types considerable controversy. From the perspective of gestational age, that <34 weeks of pregnancy with the twins suitable vaginal delivery. Lu combination from the first type of fetal considerations, it is now generally agreed: ① the first - the first of twin, to vaginal delivery, two maternity collision hinder the possibility of very small, unless with prolapsed umbilical cord, placenta previa, pre-eclampsia or fetal Film secondary uterine contractions early break weak, the handling of the tip is not better, otherwise no indications of cesarean section. ② the first cross-fetal indications for cesarean section. ③ first fetal breech presentation, can not guarantee the safety of vaginal delivery, cesarean section is also properly. Olofsson, etc. (1985) that pregnancy> 36 weeks, for the first fetal breech presentation, dealing with the same single-fetal breech presentation, should be held pelvic X-ray measurements, to really integrate 115 mm diameter and the diameter of exports between the ischial tuberosity Drive + + ischial spine diameter = 325 mm between the critical standards, the standards are below the line cesarean section.

On the first - or the first hip - Wang places, the first fetal vaginal delivery, the non-first-second fetal delivery also in dispute. Some people advocate that the second fetus regardless of the breech or transverse position, as are the reverse of the first. However, the general view is still in the breech delivery or reverse out for the best after the breech. Past that the previous vaginal delivery after cesarean section to allow the criteria for a single child, the first place under paragraph transverse uterine incision, reflect recent studies do not meet the above criteria may also be a good mother and infant outcomes, suggesting that the appropriate choice cesarean section After the twin pregnancy can be pilot production.

As for the three children or three children over the delivery of multiple pregnancy, the majority of that choice vaginal delivery, delivery prone to adverse placental perfusion and placental abruption, and should be quick, only in the implementation of a obstetric complications during cesarean section operation.

2. Vaginal delivery of the three-way deal with: the twin pregnancy decision vaginal delivery, after the first stage of labor processing, in principle, and singleton pregnancies without distinction. If the first fetal fetal membranes from breaking with prolapsed umbilical cord, should immediately make ups, push hands on the first open fetal avoid umbilical cord compression, radical Cesarean Section. If the uterine atony to extend the birth process, the use of conventional-dose intravenous oxytocin strengthen contractions, but the results are not significant, they are advised to use cesarean section.

Labor progressed smoothly in the first fetus to be born, to be intravenous infusion, to prepare for blood transfusion. The first fetus is delivered not too fast to prevent placental abruption. The first baby is delivered immediately after the fault umbilical, placental side clamping the umbilical cord stump must to prevent a second fetus hemorrhagic immediately for abdominal examination, as far as possible, to reinstate the second fetus was longitudinal middle - to prevent intrauterine pressure because suddenly reduced volume and intrauterine still larger scope of activities to a large horizontal position. Vaginal examination clear births and fetal first-Lu, certainly for the first or buttocks first exposed, appropriate oppression at the bottom of the Palais, close monitoring of fetal heart tones, wait patiently. If after five minutes, no movement and contractions weakened, in the monitoring of the fetal heart at the same time, be artificial rupture of membrane, or re-conventional-dose intravenous oxytocin, as early intervention, resulting in a reduced intrauterine pressure faster and increase fetal injury. In view of the first baby is delivered, the placenta uterine contractions in the uterine blood flow reduction, it may affect the fetal oxygen supply, as well as the possibility of cervical shrink-formed Central contraction affect fetal delivered, should strive to end within 20 minutes childbirth. If found umbilical cord prolapse or suspected of placental abruption, timely delivery by forceps or breech traction is delivered to the second fetus; such as fetal head floating high for the rescue fetus, and the possible reversal in the hip traction. If in the second fetus for the horizontal position can be intermittent contractions in the pilot phase of the reverse conversion to breech the first place or, if unsuccessful, should be reversed immediately AA for the hip and the traction is delivered. In the second fetus is delivered before the shoulder, intravenous injection of 0.2 mg lysergic new base (hypertension disabled), to speed up the oxytocin infusion. The second baby is delivered, sand bags placed on the abdomen (1 kg weight) or Fudaijinguo sudden drop in the abdomen to prevent abdominal pressure caused shock. Palace at the end of close observation height and vaginal bleeding, actively seized of the third stage to prevent postpartum hemorrhage. Placenta is delivered, should be carefully examined the placenta and fetal membranes is complete, and in accordance with the placenta and fetal membranes of the situation, and to further determine a single or double egg egg twins. After two hours, maternal blood pressure and heart rate stable, reducing the weight of sand bags; 24 hours to withdraw.

Three children and three children of pregnancy by more than vaginal delivery to deal with similar twin pregnancy.

3. Twins or two interlocking collision treatment: first twin pregnancy for the fetus exposed buttocks first, the second fetus to reveal for the first time, delivery may occur in the process of two interlocking, which is gradually decreased in the first fetus process, the head of the second fetus had been the first drop Rugu basin, which of the two fetal chin mutual Gouzhu caused birth. The kind of special maternity complications rare, occurring mainly in smaller fetal or maternal pelvic too much, especially single amniotic twins, or the second fetal amniotic sac early break situations. Production process such as the slow decline in the discovery of the first fetus, that is, there should be vigilant against the possibility of two interlocking, timely for X-ray diagnosis can be clear. Once in two interlocking, manipulative reduction rather difficult. If the first fetus to survive, to visit urgent cesarean section suitable. If found later, the first fetus has died, to preserve possible breakage of the second fetus; if the surgery was very difficult and should not be delayed, should immediately cesarean section to save the second fetus.

The two twin fetuses are exposed to the first, if smaller and maternal fetal pelvis leniency, possibly two Rupen fetal head at the same time, causing a collision between dystocia. In the delivery process, such as uterine I have opened all the first fetal decreased slowly, and vaginal examination should be carried out as soon as possible. If confirmed with abdominal second fetal head has been part of the most wide below the pubic symphysis, the vagina, cervix Shenzhi push on the second fetal head to give way to the first fetal head to drop.


[Etiology:




1. Genetic factors: multiple pregnancies family sexual orientation, couples who have one birth in the family of multiple births, the incidence of multiple births increased. Single egg has nothing to do with genetic twins. Two-egg twins are obvious genetic history, if the women themselves for the two-egg twins of twin births than the probability of two-egg twins for her husband and one higher, suggesting that the mother's genotype impact than the father.

2. Age and parity: single-egg twins age on the incidence of impact not obvious. Hauser, such as single-egg twins found that the incidence in women under the age of 20 for 3 ‰, and> 40 years of age was 4.5 ‰. Two-egg twins in the age of the rate of growth was significantly increased in the 15 to 19 age group, only 2.5 ‰, and 30 to 34 age group increased from 11.5 ‰. The production increase has also increased the incidence of twins, Chai and others (1988) reported primipara 21.3 ‰, 26 ‰ more maternal.

3. Endogenous gonadotropin: the spontaneous double-egg twins occur in vivo and follicle stimulating hormone (FSH) level of the higher. Mastin, etc. (1984) found that the delivery of twin women, its blood early follicular phase FSH levels were significantly higher than single births, births. Women's clothing stopped after a contraceptive, pregnancy, a two-egg twins increased the ratio may be increased pituitary gonadotropin secretion, resulting in a number of Shiji follicular maturation results.

4. Ovulation drugs Applications: multifetal pregnancy is the main drug-induced ovulation complications. And individual differences in response, the volume of the. Application of human menopausal gonadotrophin (HMG) in the course of treatment prone to ovarian hyperstimulation that multiple ovulation, in the twin opportunities will increase by 20% to 40%.


[Clinical]




Multifetal pregnancy, early reaction heavier, longer duration. After 10 weeks of pregnancy, uterine volume significantly higher than single pregnancy to 24 weeks pregnant after more rapid growth. Late pregnancy, due to excessive uterine increased diaphragmatic pushed upwards to the lungs and diaphragm compression rate decreased activity, often breathing difficulties due to excessive force under increasing uterine cavity and pelvic vein, hinder venous return, often induced lower extremity edema and abdominal and lower extremities and vulvovaginal varices. In addition, many special complications during pregnancy, including the general and special complications.


[Complications]




A general complications

1. Abortion: twin pregnancy rate of spontaneous abortion of 2 to 3 times the single pregnancy. The more the number of fetuses, the greater the risk of miscarriage and fetal abnormalities, abnormalities of the placenta, placental blood circulation and uterine volume obstacles to the relatively narrow.

2. Fetal malformations: twin pregnancy fetal malformation rate higher than single births times, single-egg twins is deformed babies of the two-egg twins 2 times. The reasons for the increased malformation rate is not clear, intrauterine compression can be caused by foot deformities, congenital hip dislocation, and other local fetal malformations, but has nothing to do with the type of placenta, or the basis for the increase in chromosomal abnormalities.

3. Intrauterine growth retardation: 30 gestational weeks ago, the growth rate of twin fetus and fetal similar single, then that is slowing down. Intrauterine growth retardation incidence of 12% to 34%, with the extent of the growth and increasing gestational age, single-egg twins more than a two-egg twins.

4. Anemia: As the increase in blood volume, large iron intake requirements are inadequate or poor absorption, the second half of pregnancy have more iron deficiency anemia. Folic acid requirements during pregnancy increased urine output increased because of lack of food or gastrointestinal absorption of obstacles and lack of habitation formed after Giant David RBC anemia.

5. Pregnancy-induced hypertension: a single pregnancy rate three times, early onset of symptoms and most severe, often beyond our control, eclampsia complication rate is high.

6. Polyhydramnios: 5% to 10% of twin pregnancy in amniotic fluid excessive incidence of a single pregnancy 10 times, in particular predilection for single-egg twins, and often occurred in one of the fetus.

7. Placenta previa: As placenta large area, easily extended to the lower uterine cervix, mouth and coverage, a placenta previa, the incidence was higher than that of single births doubled.

8. Premature: Since excessive uterine extension, in particular the number of fetuses, with polyhydramnios, intrauterine pressure too high, the high incidence of premature delivery. Most premature for the naturally occurring, or because after premature rupture of membranes. According to statistics, the average twin pregnancy only 37 weeks of pregnancy.

Second, special complications

1. Twin transfusion syndrome: chorionic mainly single-egg twins the serious pregnancy complications, since the two fetal blood circulation through the placenta vascular anastomosis communication, in which the blood transfusion caused uneven flow.

2. One of the twin intrauterine death: multiple pregnancy, not only abortion, premature births than single, fetal deaths occurred亦多. Sometimes, one of the twins died of intrauterine, and the other is to continue to fetal growth and development.

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