Maternal and fetal health screenings for high-risk pregnancies, such as thalassemia in the fetus, gestational diabetes, preterm labor, twin pregnancy, and preeclampsia, are some of the most common pregnancy complications. If not diagnosed and treated early, these conditions can affect the health of the mother and the life of the fetus. Therefore, early diagnosis, treatment, and prenatal care are crucial, especially for high-risk pregnancies (High – Risk Pregnancy), which is an important screening method that should not be neglected.
Pregnancy Screening
Screening for pregnancy can be done in the following ways:
- Screening every pregnant woman, which involves screening all pregnant women regardless of whether the pregnancy is considered high-risk or not, such as screening for red blood cell size and shape, ABO and Rh blood groups, syphilis infection, hepatitis B virus, HIV, and urine tests for protein and glucose. Thailand has a high prevalence of thalassemia, so it’s recommended to screen all pregnant women for thalassemia.
- Screening specific to pregnant women at high risk, which involves screenings for specific conditions that are a high risk for pregnancy complications, such as gestational diabetes screening, and predicting preterm labor, etc.
Thalassemia
Thalassemia is the most common genetic disease in the country. Around 30 – 40 percent of the Thai population are carriers, and about 1 percent or approximately 600,000 people of a population of 60 million are patients, with more than 12,000 new cases annually. Patients often show severe pallor, jaundice, and enlarged spleen from a young age, some starting from 1 – 2 months old. Growth is slower than normal, and chronic severe anemia causes changes in bone marrow, especially in the facial bones. Blood transfusions can extend the life of patients. These patients have a risk of iron overload, one of the major complications being heart failure, among other issues like cirrhosis and diabetes. Treatment mostly involves managing symptoms or supportive care throughout life.
These diseases can be cured with a stem cell transplant from cord blood if the tissues of the fetus match those of a sibling, at least 25% of the time. If there is a match, a stem cell transplant from the cord blood of the sibling may cure the disease. The success in preventing thalassemia depends on the ability to screen for carriers or at-risk spouses. Generally, carriers of thalassemia are healthy but have abnormal red blood cells, which does not affect their health. Genetic counseling and prenatal fetal diagnosis can reduce the incidence of thalassemia. Given the high number of carriers in Thailand, universal screening is recommended for all pregnant women.
Gestational Diabetes
Gestational diabetes increases the risk of complications, preeclampsia, and preterm birth in the mother, and increases the possibility of fetal death in the last 4 – 8 weeks of pregnancy. Mild gestational diabetes does not increase the risk of preterm birth mortality, but it does result in larger infants and more difficult deliveries, leading to possible postpartum hemorrhage. Twin pregnancies (believed to be caused by the fetus urinating excessively) have been associated with low blood sugar levels after birth, jaundice, and low blood calcium levels. Long-term effects of gestational diabetes increase the risk of diabetes after delivery, including the genetic risk of obesity and diabetes in offspring.
Screening and diagnosis from the onset of pregnancy and care can help prevent various complications. Initial screening involves drinking a 50-gram glucose solution followed by a blood sugar level test 1 hour later (50-g Glucose Challenge Test). If abnormal, with blood sugar levels equal to or greater than 140 mg/dL, a 100-gram OGTT (3-Hour) test is conducted after fasting for 10 – 12 hours, followed by drinking a 100-gram glucose solution and testing blood sugar levels before and after drinking the glucose solution.
Preterm Labor and Birth
Preterm labor and birth are complications leading to disability and are a common cause of neonatal death. This condition refers to labor and birth from week 28 to before week 37. It typically occurs in 9 – 10 percent of births, with no clear cause identified but a likelihood of recurrence in subsequent pregnancies. Risk factors include infections at the cervix or in the amniotic fluid, preeclampsia, placenta previa or premature detachment, multiple pregnancies, weak cervix due to injury from abortion or delivery, or cervical surgery, abnormal uterine shape, stress, anxiety, malnutrition, and insufficient rest, affecting the chances of preterm delivery.
Diagnosis involves detecting uterine contractions and cervical changes, with at least 4 contractions in 20 minutes, or 8 in 60 minutes, along with cervical dilation more than 1 cm and thinning at least 80%. Symptoms may include back pain, menstrual-like cramps, clear or bloody vaginal discharge, which must be distinguished from false labor, where contractions are irregular, and pain might be mild or absent.
Predicting Preterm Labor
- An internal examination to assess cervical dilation and effacement is simple and economical but varies greatly and is less sensitive.
- Ultrasound measurement of cervical length, with a normal length around 35mm at 24 weeks of pregnancy. A progressively shortening length increases the risk of preterm birth, offering a more accurate risk assessment than internal examination.
- Fetal Fibronectin testing from the vaginal canal, which has high sensitivity and can help reduce unnecessary treatments.
Treatment
The primary goal of treatment is to extend the pregnancy, especially before 34 weeks, to reduce the chances of lung failure in the newborn.
Treatment for preterm labor requires confirming the diagnosis, determining gestational age through history, physical examination, and ultrasound to identify the cause of preterm labor. Monitoring the health of the fetus in the womb, selecting medications to inhibit uterine contractions, and using corticosteroids to stimulate fetal lung function are essential.
Gestational Hypertension
Gestational hypertension is defined as a systolic blood pressure from 140 mmHg or diastolic blood pressure from 90 mmHg. Preeclampsia is diagnosed with blood pressure from 140/90 mmHg and protein in the urine.
Preeclampsia
Preeclampsia, a condition involving seizures without any other found cause in patients with severe preeclampsia experiencing convulsions, is a pregnancy-specific syndrome. It is characterized by reduced blood flow to various organs before high blood pressure is detected. Patients usually gain more weight than normal, and may present with extreme swelling or significant leg edema, later diagnosed with high blood pressure. Protein in the urine is often a later finding, indicating the disease’s severity. If symptoms include headache, blurred vision, or epigastric pain, the risk of seizures is increased. Seizures can occur before delivery, during labor, or after delivery.
- Important maternal complications include cerebral hemorrhage, premature placental detachment, neurological disorders, aspiration pneumonia, and pulmonary edema.
- Significant fetal complications include oxygen deprivation from premature placental detachment.
Preeclampsia is more common in first pregnancies, younger women, differing from patients with chronic hypertension, who are typically older than 35 years, and is a pregnancy following other significant risk factors, such as obesity, twin pregnancy, low platelet count which is the most common abnormality, hemolytic anemia, kidney, liver, and brain dysfunction.
Treatment
Ending the pregnancy is the primary treatment. The care approach includes preventing seizures, controlling high blood pressure, and concluding pregnancy when it’s full term, the mother shows severe illness symptoms, or if fetal health is found to be abnormal.
Intrauterine Growth Restriction (IUGR)
IUGR indicates a condition where the fetus in utero cannot grow to its genetically predetermined potential. Doctors must know the precise gestational age of the fetus because fetal weight changes with gestational age.
Causes
- Maternal Causes
- Small mothers often give birth to small-sized babies. Mothers weighing less than 45 kilograms before delivery have a twice as likely chance to give birth to smaller-than-normal babies.
- If the mother’s weight does not increase during pregnancy, for overweight mothers in good health without complications, an average weight gain may not affect the fetal weight. However, for mothers with low or average weight, no weight gain throughout pregnancy results in IUGR, especially if there is no weight gain during the second trimester.
- Infections in mothers, including viruses, bacteria, and protozoa, can cause infections in the placenta and fetus, leading to IUGR.
- Maternal diseases causing abnormalities in the placental blood vessels include high blood pressure during pregnancy, chronic high blood pressure, severe diabetes, connective tissue diseases, chronic kidney disease, diseases causing low blood oxygen levels in the mother, such as Obstructive Lung Disease, certain heart diseases, severe anemia, and conditions like Antibody Syndrome, which is associated with antibodies against Cardiolipin or Anticoagulant, causing blood clot formation and consequently placental blood vessel blockages, leading to repeated miscarriages, fetal death in utero, preeclampsia, and IUGR.
- Maternal environmental factors, such as smoking, drug use like alcohol, cocaine, opium, can cause IUGR. Poor prenatal care, malnutrition, and certain medications such as epilepsy drugs, and some types of anticoagulants, can also contribute.
- Fetal Causes include structural and chromosomal abnormalities in the fetus that may lead to IUGR.
- Placental Causes may involve structural or functional abnormalities in the placenta.
Diagnosis
- Prenatal history Screening for risk groups is the starting point for diagnosing IUGR. Mothers with chronic diseases like high blood pressure or kidney disease, or those who have previously given birth to children with IUGR, are at a higher risk. Mothers who are underweight during pregnancy and do not meet the weight criteria are also at risk. Thus, doctors should monitor the fundal height and perform ultrasounds to confirm.
- Measuring the fundal height Using a measuring tape from the top of the uterus to the pubic bone is a simple method still widely used to screen for IUGR, followed by ultrasound confirmation.
- Ultrasound High-risk mothers, either due to history or physical examination, should undergo ultrasound to confirm gestational age, assess abnormalities, and monitor fetal growth around 16 – 20 weeks of pregnancy and possibly again at 32 – 34 weeks. Assessment involves measuring standards and calculating fetal weight.
Treatment
Main principles in treating IUGR are:
- Prenatal care to identify and reduce risks worsening fetal health and to promote fetal growth.
- Close monitoring of fetal health during pregnancy, including counting fetal movement, which is a simple and convenient way to assess fetal health. Normally, the fetus should move at least 10 times within 12 hours daily. Using high-frequency ultrasound for Biophysical Profile, Doppler ultrasound, and monitoring fetal heart rate electronically are standard methods for monitoring fetal health, typically on a weekly basis.
- Prenatal care and determining the appropriate timing for delivery. Bangkok hospital’s women’s health center is ready to provide comprehensive care for pregnant women according to academic and technological advancements, focusing on patient-centric care, from diagnosing prenatal abnormalities to postnatal care, ensuring the newborn is healthy and strong.
