multiple births
Introduction
Introduction to multiple births A pregnancy has two or more fetuses at the same time, called multiple pregnancy, but does not include multiple pregnancy or uterine fallopian tube pregnancy. In human multiple pregnancy, twins are most common, three are rare, and four and four are rare. Although multiple pregnancy is a physiological phenomenon, the complications and mortality of multiple pregnancy are higher than single pregnancy, the risk of severe disability in twins is 2 times higher, and the third is 3 times higher. Therefore, multiple pregnancy is a high-risk pregnancy. Category, clinical should pay more attention. Since drug-induced ovulation and in vitro fertilization (IVF), three- and three-child pregnancies have received widespread attention. Multiple pregnancy has many complications during pregnancy and childbirth, and the perinatal mortality and neonatal mortality are high. Therefore, it is a high-risk pregnancy. In order to improve the pregnancy outcome, in addition to early diagnosis, the pregnancy care should be strengthened and the delivery period should be emphasized. basic knowledge The proportion of illness: 0.02% Susceptible people: women who are pregnant during pregnancy Mode of infection: non-infectious Complications: anemia, polyhydramnios, premature delivery
Cause
Multiple causes
Genetic factors (30%):
Multiple pregnancies have a family-like tendency. In a family with a couple, there are multiple births, and the incidence of multiple births increases. Single-oval twins are not related to heredity. Double-female twins have a clear genetic history. If women are one of the twins, The probability of giving birth to twins is higher than that of husbands who are twins, suggesting that the mother's genotype affects her father.
Age and parity (25%):
The effect of age on the incidence of single-oval twins is not obvious. Hauser et al found that the incidence of single-oval twins was 3 in women under 20 years old, and 4.5 in >40 years old. The incidence of double-oval twins increased significantly with age. The increase was only 2.5 in the age group of 15-19 years old, and increased to 11.5 in the 30-34 age group. The incidence of twins increased and the incidence of twins increased. Chai et al. (1988) reported that the primipara was 21.3, and the majority of women were born. It is 26 baht.
Endogenous gonadotropin (20%):
The occurrence of spontaneous double-oval twins is associated with higher levels of follicle stimulating hormone (FSH) in the body. Mastin et al (1984) found that women who gave birth to twins had significantly higher levels of blood FSH in the early follicular phase than those who gave birth singles. One month after taking the contraceptive, pregnancy, the incidence of double-oval twins increased, may be the result of increased secretion of gonadotropins in the pituitary gland, leading to the maturity of multiple primordial follicles.
Application of ovulation induction drugs (15%):
Multiple pregnancy is the main complication of drug-induced ovulation. It is related to individual reaction, and the dose is too large. It is prone to ovarian hyperstimulation during the treatment of human menopausal gonadotropin (HMG), resulting in multiple ovulation and chance of twins. Will increase by 20% to 40%.
Prevention
Multiple pregnancy prevention
1, the rational application of ovulation induction drugs: multiple pregnancy is the main complication of drug-induced ovulation. It is related to the difference in individual response and the dose is too large. The use of human menopausal gonadotropin (HMG) treatment is prone to ovarian hyperstimulation, resulting in multiple ovulation, the chance of twins will increase by 20% to 40%.
2. Limit the number of embryos implanted in the uterus.
3. Carry out new transplantation technologies.
4, the appropriate use of selective reduction surgery.
Complication
Multiple complications Complications, anemia, amniotic fluid, premature delivery
First, general complications
1. Abortion: The spontaneous abortion rate of twin pregnancy is 2 to 3 times that of singleton pregnancy. The more the number of fetuses, the greater the risk of miscarriage, the abnormality of embryos, the abnormal development of placenta, the blood circulation disorder of placenta and the relatively narrow uterine volume. related.
2, fetal malformation: the fetal malformation rate of twin pregnancy is 2 times higher than that of single fetus, the number of single-oval malformation is 2 times that of double-oval twins, the cause of increased deformity is not clear, intrauterine compression can cause deformity Foot, congenital dislocation of the hip and other fetal malformations, but not related to placental type, there is no basis for increased chromosomal abnormalities.
3. Intrauterine growth retardation: Before 30 weeks of gestation, the growth rate of twin fetuses is similar to that of singleton, and then slows down. The incidence of intrauterine growth retardation is 12% to 34%, and the degree increases with gestational age. And aggravated, single-oval twins are more significant than double-oval twins.
4, anemia: due to increased blood volume, iron needs a large amount of insufficient intake or malabsorption, iron deficiency anemia in the second half of pregnancy, increased folic acid requirements during pregnancy and increased urine output, if due to food content Insufficient or lack of gastrointestinal absorption, it is easy to cause megaloblastic anemia.
5, pregnancy-induced hypertension syndrome: the incidence rate is 3 times that of singleton pregnancy, the symptoms appear early and severely, mostly difficult to control, the rate of eclampsia is also high.
6, amniotic fluid: 5% to 10% twin pregnancy occurs too much amniotic fluid, the incidence is 10 times that of single pregnancy, especially in single-oval twins, and often occurs in one of the fetuses.
7, placenta previa: due to the large area of the placenta, easy to extend to the lower part of the uterus and cover the internal cervix, forming a placenta previa, the incidence is 1 times higher than a single.
8, premature delivery: due to excessive stretching of the uterus, especially the number of fetuses, and excessive amniotic fluid, intrauterine pressure is too high, the incidence of premature birth is high, most premature birth occurs naturally, or due to premature rupture of membranes, according to statistics twins The average gestation period for pregnancy is only 37 weeks.
Second, special complications
1, twin fetal transfusion syndrome: mainly a serious complication of monochorionic single-oval twin pregnancy, due to the blood circulation of the two fetuses through the placental anastomosis of the blood vessels, blood transfusion and imbalance of blood flow.
2, one of the twins in the intrauterine death: multiple pregnancy, not only abortion, premature birth more than singleton, there are more intrauterine deaths, sometimes, one of the twins died in the palace, the other fetus continued to grow and develop.
Symptom
Symptoms of multiple births Common symptoms Increased uterus enlargement (... Early pregnancy response, severe fetal movement, frequent menopause, weight gain
1. The early pregnancy response is heavy, the uterus is enlarged obviously, and the uterus gains more than the corresponding menopause month, and the fetal movement is frequent;
2, in the third trimester of pregnancy may have difficulty breathing, lower extremity edema, varicose veins and other compression symptoms, often accompanied by anemia;
3, the abdomen can be a plurality of small limbs and two fetal heads, hear two different rates of fetal heart sounds, the difference between each minute more than 10 times, there is no sound zone between the two fetal heart intervals.
Examine
Multiple tire inspection
1. After the embryo has a rhythmic beat of the original heart tube, after 12 weeks of pregnancy, fetal head imaging, can measure the double top diameter of each fetal head, with the growth of gestational age, the diagnostic accuracy rate can reach 100%, Therefore, the clinical suspected multiple pregnancy is more, should continue to follow up until the number of fetuses is completely determined.
2, Doppler ultrasonography: after 12 weeks of pregnancy, Doppler fetal heart rate can be heard the frequency of fetal heart sounds.
3, serum alpha-fetoprotein determination: also contribute to the diagnosis of multiple pregnancy, in twin pregnancy, 29.3% serum alpha-fetoprotein value increased significantly; three-child, 44.8%; four and four or more, up to 80.0%, therefore, when screening pregnant women serum alpha-fetoprotein value is abnormally elevated, suggesting multiple births may require further examination.
B-ultrasound diagnosis of chorionicity in twin pregnancies, the following steps can be taken in sequence:
(1) If you see two placenta, it is double chorionic;
(2) If only one placenta, determine the gender of each fetus, the opposite sex is a double chorionic pregnancy;
(3) If the sex of the twins is the same, carefully check the separation membrane, the 4 layers must be double chorioamnion, and the 2 layers are monochorionic double amniotic membrane. After the pregnancy enters the medium term, it will be monitored by series B ultrasound, if found: 1 Inconsistent fetal development, fetal double top diameter difference > 5mm or head circumference difference > 5%, abdominal circumference difference > 20mm; 2 amniotic fluid volume is significantly different; 3 a fetus with edema, can make a diagnosis of chronic transfusion syndrome.
In multiple pregnancy, the early pregnancy reaction is heavier and lasts longer. After 10 weeks of pregnancy, the uterus volume is significantly larger than the single pregnancy, and it grows more rapidly after 24 weeks of pregnancy. In the third trimester, the uterus is pushed upwards due to the excessive enlargement. To reduce the pressure of the lungs and diaphragm muscles, often have difficulty breathing; due to the excessively enlarged uterus forced the inferior vena cava and pelvic cavity, obstructing venous return, often causing edema of the lower extremities and abdominal wall, lower extremities and vulvovaginal varices, in addition There are many complications during multiple pregnancy, including general and special complications.
Diagnosis
Multiple fetal diagnosis
Diagnose based on
1. The uterus is larger than the corresponding pregnancy month;
2, the abdomen can have two or more fetal heads, two different frequency fetal heart, and there is no sound zone;
3. Ultrasound examination shows two or more fetal images and fetal heart.
Differential diagnosis
Pay attention to the identification of a large fetus, a single fetal amniotic fluid, pregnancy with uterine fibroids or ovarian cysts.
