Q1: What are birth defects in newborns?
Birth defects are congenital developmental abnormalities of the embryo or fetus in the structure or function of the digestive, cardiovascular, neurological, urinary and limb systems, and it is often the leading cause of death in small infants within one year of birth.
Q2.What are the causes of birth defects in newborns?
There are about four categories of causes of birth defects in newborns.
First, genetic factors: abnormal chromosomes of the father or mother are inherited to the offspring, resulting in abnormal chromosomal structure of the fetus.
Second, maternal factors: maternal nutritional deficiency or excess nutrition can cause abnormal fetal development. For example, insufficient protein intake or high blood sugar of the mother can cause fetal brain dysplasia and congenital cataract; lack of folic acid in pregnant women can also cause abnormal development of the fetal central system.
Third, the drug factor: in the 18 days to 12 weeks after conception, the mother used drugs may cause fetal malformations. The first isotretinoin, antiepileptic drugs, angiotensin converting enzyme inhibitors and antihypertensive drugs such as Kepitone. All will have a negative impact on the fetus.
Fourth, the physical chemical biological factors: fertilized egg formation process, a variety of physical chemical or biological reasons may cause genetic mutation or genetic recombination; physical teratogenic factors are radiation, noise, high heat, etc.. The use of electric blankets in early pregnancy and sleeping on a hot bed in winter are the most common physical factors of fetal teratogenesis. Biological factors refer to the infection of pregnant women with pathogenic microorganisms such as bacteria and viruses. Chemical factors refer to the exposure of pregnant women to harmful (toxic) chemicals, such as pesticides, methanol from renovated houses, etc.
Q3: What is the tertiary prevention of neonatal birth defects?
Primary prevention: etiology prevention, pre-conception intervention for etiology, genetic counseling for pregnant women in the first trimester, reasonable nutrition, moderate exercise, work rest, psychological counseling if necessary, etc.
Secondary prevention: prenatal diagnosis, after pregnancy, through different means of examination, the detection of abnormal fetus, can be terminated to prevent the birth of children with congenital defects. Secondary prevention includes screening tests and confirmatory tests during pregnancy. In China, serological tests are performed before 16 to 20 weeks of pregnancy to screen for fetal malformations and assess the risk factor for malformations. If it is greater than normal, amniocentesis is performed to extract fetal body fluids or cells for examination to rule out chromosomal and metabolic abnormalities in the fetus.
Tertiary prevention: It refers to the correction of congenital defects that have already been caused, including surgical and pharmacological treatment of the fetus and newborn. The former refers to the treatment given to the fetus in utero, such as fetoscopic fetal surgery, ultrasound-guided interventional surgical treatment and pharmacological treatment. The latter refers to surgical and medical treatment of the newborn after delivery of the fetus. The correction of intrauterine fetuses and newborns compensates to a large extent for the congenital defects of the affected children and reduces the level of disability in adulthood.
Q4: What are the causes of fetal death and fetal malformations?
The causes of fetal death include two factors, maternal systemic diseases and fetal own factors. Maternal systemic diseases, commonly maternal diabetes mellitus and hypertension, unsatisfactorily controlled diabetes mellitus and hypertension can cause fetal death, preconception and pregnancy-related connective tissue diseases and any disease that causes maternal sepsis and hypoperfusion can cause fetal death.
The fetal factors that cause intrauterine fetal death are
1. bacterial or viral infections
2. fetal immune hemolytic disease
3. Accidental umbilical cord, including prolapse, thrombosis, wrapping around the neck bundle or knotting, torsion
4. Metabolic disorders
5. Abnormal placental function, including fetal growth restriction, overmaturity, placenta previa, infarction, placental abruption causing hypoxia, twin fetus transfusion syndrome.
6. Genetic diseases
Any factors that cause birth defects in newborns may cause fetal malformations or intrauterine fetal death
Q5：What should be done before pregnancy?
Since many factors can cause congenital defects in the fetus, what should couples of childbearing age do to minimize birth defects in their offspring? First of all, in the first trimester of pregnancy, couples should first visit the hospital for pre-conception counseling, which is also the primary prevention of birth defects. Pre-conception counseling includes genetic counseling and necessary psychological counseling, providing the doctor with the past medical history of both partners, completing the necessary physical examination, gynecological examination and some laboratory tests, such as routine blood and urine tests, blood biochemical tests and some immunological tests. Secondly, a balanced diet and healthy diet before and during pregnancy is an important means to reduce pregnancy complications, with a diversified diet, no partiality or anorexia, and avoiding excess nutrition, such as a high-fat, high-sugar diet. Exercise properly to enhance immunity and avoid colds in early pregnancy. Strive to quit smoking and alcohol. Although the outcome of pregnancy is the result of the interaction of maternal, fetal and environmental factors, and it is difficult to attribute pregnancy outcome to one particular intervention, scientific studies have clearly demonstrated that preconception counseling can improve pregnancy outcome.
Q6: Do I have to get the rubella vaccine before pregnancy?
Rubella infection is usually a mild disease for adults and children, however fetal infection can be extremely serious. Congenital rubella syndrome may manifest as transient abnormalities, including purpura, splenomegaly, jaundice, meningitis, thrombocytopenia, or as permanent disorders such as cataracts, glaucoma, heart disease, deafness, microcephaly and mental retardation. In addition, distant sequelae may include diabetes mellitus, thyroid abnormalities, precocious puberty and progressive rubella meningitis. In fact, defects occurring in various organs after rubella infection have been reported. The rubella vaccine was introduced in the United States in 1969. The vaccine was administered as a trivalent (measles, mumps, rubella, MMR) vaccine that produced long-lasting immunity in 95% of those vaccinated. The incidence of rubella dropped dramatically after the vaccine was applied. Therefore, rubella vaccination in the first trimester can prevent viral infection of rubella during pregnancy and is also a primary prevention of birth defects.
Q7: How can pregnant women take proper folic acid supplementation?
Folic acid supplementation is recommended for all women who intend to become pregnant, precisely 0.4mg/day orally starting 3 months before conception and continuing until 3 months after pregnancy. Pregnant women with an increased risk of fetal neural tube defects during pregnancy are even more likely to need to provide continuous folic acid supplementation. Folic acid supplementation is beneficial in preventing fetal neural tube abnormalities such as anencephaly, spina bifida, and cerebrospinal meningeal panglion. China has started to implement free oral folic acid for 6 months for rural women of relevant reproductive age.
Q8: How to do ultrasound during pregnancy?
The benefits of routine ultrasound screening include: determining gestational age, estimating fetal weight in late pregnancy, reducing the rate of induction of labor in late pregnancy, detecting multiple pregnancies, and fetal growth restriction, and identifying fetal malformations.
In early pregnancy, routine ultrasound is not recommended without special circumstances, unless there are symptoms such as vaginal bleeding and abdominal pain, but if you need to determine the gestational age, ultrasound can be performed at 8-13 weeks, when gestational age = fetal parietal-rump diameter + 6.5. In addition, ultrasound at 8-13 weeks can also be used to screen for fetal chromosomal abnormalities by measuring the width of the posterior cervical zona pellucida —- Down’s syndrome.
2.Mid pregnancy, such as 24~28 weeks, can be used to screen the fetus for fetal morphological abnormalities
3.32~34 weeks, ultrasound can estimate fetal size and exclude fetal growth restriction, placenta previa, etc. It can also detect some late-onset fetal malformations such as polycystic kidney, hydronephrosis, etc.
At 4 and 38 weeks, it is the ultrasound before delivery, which can determine the biophysical score of the fetus, estimation of fetal weight, measurement of placental maturity, measurement of amniotic fluid volume, etc.
Q9: Which pregnant women need chromosome examination?
An abnormal fetal phenotype can be caused by environmental factors, chromosomal abnormalities, specific genes, or more complex genetic mechanisms. For most couples, finding a fetal abnormality is unexpected, but some factors suggesting a high fetal risk can be detected, and chromosomal testing is recommended for pregnant women who have
1.Previously had a child affected by a monogenic genetic disorder
2. Family history of monogenic disorders
3. Fetal structural abnormalities found during ultrasonography
4. History of recurrent miscarriage: i.e. 3 or more consecutive miscarriages
5. The risk of miscarriage is highest among couples with female partner aged ≥35 years and male partner aged ≥40 years, and the chance of embryonic chromosomal abnormality is increased, and chromosomal examination of both partners is done when couples with recurrent miscarriage are consulted.
Q10：What should women with hypertension pay attention to when they get pregnant?
In women with chronic hypertension, pregnancy may worsen the original condition or combine with preeclampsia, and additional medication and medically induced preterm delivery are increased. Tests should be performed to look for an obvious cause of hypertension and to assess kidney and heart function. Most women with primary hypertension should be managed correctly if the cause is identified before pregnancy. In many cases, obesity is a synergistic factor that can be modified by weight loss. In addition to lowering blood pressure, weight loss has other benefits: reduction in ventricular volume, hyperinsulinemia, diabetes mellitus and hypertriglyceridemia. The choice of antihypertensive medication should avoid drugs that have serious effects on the fetus, such as angiotensin-converting enzyme inhibitors, which can cause fetal malformations.
Q11: Can gestational diabetes affect the fetus?
The answer is yes.
The embryo is particularly sensitive to the teratogenic effects of hyperglycemia, and neural tube defects, heart and kidney malformations are often two to five times more likely to occur in diabetic pregnancies. Rare malformations such as sacral hypoplasia and anencephaly are also common in fetuses of women with severe diabetes. Elevated fasting glucose in the mother increases the risk of fetal death in the last 4 to 8 weeks, and statistics show that gestational diabetes increases fetal mortality.
Q12: Is it strongly contraindicated to use medication during pregnancy?
Most medications can act on the embryo and fetus through the placenta, and many are harmful to the embryo and fetus, so before you take any medication, you should refer to the pharmaceutical manufacturer’s instructions and FDA clearance to clarify whether the medication is contraindicated for pregnant women. If you do need to use a drug during pregnancy, you must weigh the pros and cons.