Fetal Abnormalities – Causes, Checkups, and How to Avoid

Though fetal abnormalities and heredity are greatly influenced by its environment, medication and stress, most anomalies are largely unknown. With everyone planning for pregnancies nowadays, there are fetal checkups to thoroughly screen malformations. These are some of the best ways to prevent fetal abnormalities.

What are Fetal Abnormalities?

Innate abnormalities and acquired abnormalities

Abnormalities are largely categorized into two types – innate or acquired. Innate abnormalities happen in the uterus when the mother is pregnant. Acquired abnormalities refer to situations in which the baby is normal inside the uterus but malformations develop in its body after birth. Some fetal abnormalities are discovered during pregnancy and treatments are administered before birth. Subsequently, the condition is treated or diminished. There are other anomalies which are treated after birth and the baby recovers. There are also immediate deaths upon births.

Women more prone to giving birth to babies with abnormalities

fetal abnormalities

Between couples, one of them has a family member who becomes sick due to a chromosomal abnormality. A pregnant woman who is currently sick is also more susceptible to carrying a baby with malformations. The rate of fetus abnormalities increases drastically in expectant mothers who are in advanced age or have been on medication for a long time due to sickness. It's wise to consult a doctor before making pregnancy plans if a woman has given birth to a malformed baby or a stillborn or has undergone repeated and habitual abortions.

Reasons for Abnormalities

1) Malformation due to a single gene

This type of fetus abnormality is caused by either the father or mother passing on the defective gene from their side of the family to the fetus. There's one instance of such abnormality happening in every 100 pregnant women. There are 3,900 types of diseases caused by a single defective gene. Chromosomal diseases arising from a single gene can be further divided into four types: male diseases arising from double chromosome mutations, female diseases arising from double chromosome mutations, half-formed female diseases and half-formed male diseases.

Male diseases arising from double chromosome mutations include dwarfism, the Human Elephant Disease (human skin becomes rough and dark like that of an elephant) and Huntington's disease which causes paralysis of the body, progressive brain disorder and dementia. Female diseases arising from double chromosome mutations include Phenylketonuria (commonly known as PKU) which causes intellectual disability in children, albinism, asexuality, enzyme deficiency which makes women look like men and congenital adrenalin increase, among others.

Mothers can only pass on half-formed female diseases to the baby. These include hemophilia, muscular atrophy, under-development of sexual glands and autism, among others. The representative for half-formed male diseases is rickets, which only affects women.

2) Multi-factorial genetic abnormality

This type of abnormality isn't caused by genes. It refers to abnormalities with specific symptoms that often occur in the family. Therefore, the rate of a baby with malformations appearing within the family is higher than others. This is due to genetic and environmental influences, and if the conditions are compounded, malformations will appear. Cleft lip, congenital heart diseases, and anencephaly (born without a major portion of the skull, scalp or brains) are examples of congenital deformities. Moreover, conditions such as epilepsy, mental disorders, depression andrheumatoid arthritis will appear in adults.

The representative of multi-factorial genetic abnormality is anencephaly – the condition of being born with a big part of the skull and brains missing. Only early signs of development of those vital organs remain. In cases of polyhydramnios (an excess of amniotic fluid in the amniotic sac), anencephaly is a common occurrence. When it comes to abnormal appearances, congenital hip dislocation is the most common. Generally, women suffer from congenital hip dislocation more often than men. There is a possibility of improving the condition using operation after the baby is born.

Common abnormalities in oral tissues include cleft lips or cheeks. If both parents are normal and their firstborn has such anomalies, there's a 40% possibility that their second child will have this condition as well.

3) Chromosomal abnormalities

7.5% of all fetal abnormalities occur when there are anomalies in the chromosomes. However, most mothers expecting fetuses with chromosomal abnormalities will have spontaneous miscarriages. Only 0.6% of babies whose chromosomes cannot divide which subsequently leads to anomalies in chromosome structures and numbers are born.

The disease representatives of chromosomal abnormalities are Down syndrome, mental depletion, congenital heart disease with low intelligence and polydactyly (a condition in which a person has more than five fingers per hand or five toes per foot ), among others. That's because there's a chromosomal abnormality with the secondary chromosomes of Down syndrome in one of the parents. Among healthy and normal couples, if the expectant mother is in an advanced age, there could be egg mutations which result in chromosomal abnormalities. There are three types of sex chromosomal diseases. A woman with only a single X chromosome will develop Turner syndrome which results in intellectual disability and the inability to conceive. A baby boy with more than one X chromosome will have azoospermia (a man's medical condition in which he doesn't have any measurable level of sperm in his semen). If he has more than one Y chromosome, he'll be very big and tall and has a lot of pimples on his face. Though he isn't less intelligent than the others, he'll have learning disabilities.

4) Abnormalities caused by fetal infections

If you're down with measles during 3 months pregnancy, particularly the 11th week of pregnancy, the possibility of giving birth to a deformed baby is 100%; 3 to 5 months pregnancy, particularly 11th-16th week, is 50%. The measles-stricken fetus will have cataracts, congenital heart disease and central nervous system disorders, among others. Symptoms of measles are very similar to those of a flu which may often cause delays in treatment that the expectant mother didn't even realize. Therefore, you must go for an antibody test.

Toxoplasma gondii is a type of parasite which lives on bodies of dogs, cats or other pets. Toxoplasmosis could be spread to human beings via meat or food. If pregnant women contracted toxoplasmosis, the fetus will develop conditions such as microcephaly (a condition in which the brain doesn't develop properly, resulting in a smaller than normal head), chicken pox and visual disabilities. So, stay away from pets during your pregnancy and it's obligatory that you go for anantigen and antibody examination.

5) Deformities due to the expectant mother's sickness

If the expectant mother is sick, her fetus will be affected. The fetus will definitely be affected if it's syphilis or HIV. If the pregnant mother is diabetic, it's highly possible that the fetus will have congenital heart diseases, hip dislocation, cleft lip or polydactyly. If the diabetic expectant mother doesn't receive treatment, she'll give birth to a baby with excessive birth weight (macrosomia). The diabetic mother's fetus will most likely develop abnormalities before 2 months pregnancy, particularly the 7th week. Hence, if you go for diabetic treatment during this period of time, you'll not have to worry about baby deformities.

6) Anomalies caused by medications

If you're not careful about taking medicines during your pregnancy, your recklessness may bear fatal consequences for the baby in your tummy. However, during the first trimester, the side effects you develop from medicines will result in miscarriage in most cases, so there's no need to worry about the fetus being affected by medicines. If you have a cold during pregnancy and take flu medicine once or twice, it'll not likely affect the fetus in any way. It should suffice if you just pay extra attention to certain types of medicines that are particularly dangerous. Taking medicines doesn't mean that your baby will develop fetal anomalies. It's also important to know thepharmaceutical composition of the medicine, dosage, when to take it, its expiry date and screen for fetal abnormalities. Exposure to radiation may also cause fetus abnormalities, so avoid exposing your stomach to X-rays if you can help it.

7) Effects of drinking and smoking on the fetus

It isn't an issue if you only drink a little frequently. However, if you drink a lot at one go or drink every day, acetaldehyde (a product of alcohol metabolism that's more toxic than the alcohol itself) will accumulate in the fetus' brains, impairing its intellectual ability or resulting in microcephaly.

Smoking during your pregnancy will also seriously affect the fetus. The nicotine, carbon monoxide and other harmful substances in cigarettes will be transmitted to the fetus, impeding its growth and causing its blood vessels to contract, resulting in poor blood circulation. Moreover, if the expectant mother breathes in secondhand smoke, the fetus' brain will also be affected.

General Knowledge in a Box: Medicines that Trigger Fetal Abnormalities

1) Carcinostatic medicines

Pregnant women receiving cancer treatment isn't common. If the pregnancy continues, the fetus may develop cleft lip or cheek, or anomalies in the vulva and other reproductive organs.

2) Topicalcorticosteroid creams

This is a type of treatment cream for psoriasis (a long-lasting autoimmune disease characterized by patches of red, itchy and scaly skin). Pregnant women receiving psoriasis treatment must let her doctor know.

3) Diuretic medicines

Taking such medicines during pregnancy may trigger congenital disorders in the fetus. If you're taking diuretic medicines in the later stages of pregnancy, low blood sugar andelectrolyte imbalance may arise.

4) Estrogen

It's easy to abuse estrogen usage if you haven't realized that you're pregnant. If you're using estrogen during pregnancy, make sure you discuss it with your doctor immediately.

5) Medicines made with vitamins A and D

Vitamins A and D are fat soluble. When an excess amount enters the body, it'll accumulate inside and will not be passed out of the body. This will adversely affect the fetus' bone development. Pimple treatment creams usually contain vitamin A.

6) Anticonvulsants

Expectant mothers receiving treatment for epilepsy must discuss the issue with their doctor. In the first trimester, it's better to switch to other medicines which are safer or reduce dosage.

How to Avoid Fetal Anomalies

1) Plan your pregnancy

To avoid fetal anomalies, planning your pregnancy is more important than anything else. Before getting pregnant, go for a genetic test (also known as DNA testing) and measles check. Getting vaccinated at an appropriate time is also helpful in preventing fetal anomalies. If you're getting ready for pregnancy, avoid having pets around and other things which may affect pregnancy.

2) Don't take medicines recklessly

fetal abnormalities

Medicines will affect the fetus, especially during the most sensitive period between the 3rd and 8th weeks when the neural tube (precursor to the central nervous system, which comprises the brain and spinal cord) and internal organs are being formed. After the 8th week, the fetus isn't so vulnerable to medicines anymore. However, different organogenesis (formation of organs during development) takes different time and will give rise to different abnormalities. Therefore, taking care of what kind of medicines you use throughout your pregnancy is very important.

3) Be aware of your drinking and smoking habits

Habitual drinking will lower the fetus' intelligence and result in developmental disabilities such as underdevelopment. The nicotine in cigarettes will cause babies to be underweight and increase the rate of spontaneous abortion.

4) Consume enough folic acid

Folic acid is very important for the expectant mother. It bears the critical responsibility of ensuring healthy cells are formed, especially during the first trimester. It also reduces deformities in the fetus' brain and the nervous system in the spinal cord. If you don't consume enough folic acid, there are risks of premature birth, miscarriage, low intelligence and deformities in the baby. So try to consume enough folic acid.

We realize that during food handling and processing, 50-90% of the folic acid in the food is destroyed. To consume enough folic acid, choose raw food like salads or only use low heat to cook your food. Food that are rich in folic acid include soybean flour, soya beans, spinach, tangerines, mandarin oranges, sweet potatoes, grapes, sunflower seeds and egg yolks. During the first trimester when folic acid is needed most, you may not even know you're already pregnant. Hence, it's good to eat a lot of folic acid-rich food on normal days.

5) Be careful when interacting with your pets

During pregnancy, try to stay away from animals as much as possible. If you're accidentally infected by the parasites living on your pet dog or cat, it may result in congenital baby abnormalities such as brain edema (brain swelling) and omentits (acute abdominal pain). You must go the hospital to confirm whether you've been immunized.

If you've a pet dog, you should let it receive rabies vaccination and bathe it regularly. After clearing its litter, you must wash your hands. Also avoid being licked by it. Expectant women without measles antibodies shouldn't have pets at home during her pregnancy.

Fetal Abnormality Checks and Tests

1) Measles and toxoplasmosis antibody test

When you're planning to be pregnant, one of the first things that you must do is confirm whether you've measles antibodies. Otherwise, you should get measles vaccination. Avoid getting pregnant within three months of the vaccination.

If you have pets in the house, don't forget to check for toxoplasmosis antibodies. This is done within six weeks of pregnancy by checking the expectant mother's blood.

2) The prevention of specific problems checkup

This is an examination done between 5 to 6 months pregnancy, particularly 16th and 20th weeks. If the test reveals a high tendency towards Down syndrome, an amniotic fluid test will be done. Blood will be drawn from the expectant mother to analyze the fetus' sugar protein number and human chorionic gonadotropin level (hCG, a hormone that nourishes the egg after its fertilization). Simple and affordable, this is a test often used to screen for baby abnormalities.

3) Ultrasound checkup

From the monitor which displays the fetus' various body parts, you can see whether your baby is developing well or has any external anomalies. Most pregnant mothers see ultrasound checkups as basic examinations with the ability to detect fetal abnormalities by up to 30-40%. Most will do it 3-6 times before childbirth. Precision ultrasound checkups take about 30 minutes or an hour. You should do a precision ultrasound checkup between 18 and 23 weeks of your pregnancy. There are also many teaching hospitals and common hospitals that don't offer precision ultrasound checkups.

4) The humanchorionic gonadotropin (HCG) test

If you wish to detect baby abnormalities at an earlier stage, you can get this examination when you're between 9 and 11 weeks into your pregnancy. The fetal abnormalities detection rate is up to a high 99%. Due to the steep price of this test, only pregnant mothers who belong to the high-risk group of giving birth to deformed babies will undergo this checkup.Thegenes and chromosomes of chorionic tissues from thechorion inside the uterus are taken out and examined for anomalies that could lead to fetal abnormalities.

5) Amniotic fluid checks

Expectant mothers of an advanced age that have a family history or who discover abnormalities in the prevention of specific problems checkup should do an amniotic fluid check to confirm the findings. Using ultrasonic diagnostic equipment and avoiding the fetus and placenta, amniotic fluid is extracted. Results are out in between two and three week’s time.

6) Chromosomal check

This is to prevent chromosomal anomalies in the fetus. Chromosomes are extracted from blood and then chromosome structures and numbers are checked for abnormalities. In instances where the expectant mother has given birth to a deformed baby before or has habitual abortions without any reason, both the husband and wife should do chromosomal checks when the wife is in her 16th or 18th weeks of pregnancy.

7) Cord blood examination

This is an examination done after the 20th week of pregnancy. Ultrasound detects the fetus' position and blood is extracted for abnormalities examination. Not only can chromosomes be analyzed, the fetus' overall condition can also be directly confirmed from its cord blood examination. As this involves direct contact with the fetus, everything must be done cautiously. It's only after the prevention of specific problem test results are out can then this cord blood examination be done.

8) Early Down syndrome detection

In the early stages of pregnancy, this is a basic examination to detect Down syndrome. Through examining the fetus' sugar protein number and humanchorionic gonadotropin value, an expectant mother can know whether her fetus has Down syndrome or whether its nervous system is healthy. The test can be done by simply extracting the mother's blood. If abnormalities are discovered, do the humanchorionic gonadotrophin (hCG) test in the 9th to 11th weeks of pregnancy, or do an amniotic fluid check in the 14th week.

When you’re 10th to 12th weeks pregnant, do an early Down syndrome test by analyzing the mother's blood. If you're doing an early Down syndrome test, then the prevention of specific problems checkup is not necessary.

Q&A: Demystifying Fetal Abnormalities

Question 1: There's heavy blood loss during the early stages of pregnancy and I'm worried about my health. I went for the fetal abnormalities test and the abnormality index is very high. After that, I took the amniotic fluid check and the result is normal. Is only doing an amniotic fluid check enough?

Answer 1: The amniotic fluid check can offer 99% accuracy when it comes to determining whether the fetus' chromosomes are normal. Hence, if your amniotic fluid test result is normal, you then don't have to worry about the chromosomes normality. However, apart from chromosomal anomalies, it's totally unknown whether there are other reasons for fetus abnormalities. Just do what other expectant mothers do and go for regular checkups.

Question 2: After doing an ultrasound scan, I started to worry about whether my baby's fingers and toes are all intact. I would also like to take a better look at its internal organs and spine. If there are no issues with its internal organs, it's generally assumed that everything's all right. However, there's no way to look directly, so I'm still very worried before and after childbirth.

Answer 2: Currently, the best way to look at the fetus' appearance is via an ultrasound scan. Of course, equipment has their limitations and very often you may not be able to see everything clearly. Moreover, different parts are revealed when the fetus moves or shifts its position. Generally, there are two or three abnormal fetuses in every 100 newborns. This number has been stable for a long time. Ultrasound technology is now 20 years old and we hope that there will be more advanced and better machines in the future to let ultrasound checks be more accurate. Right now, the technology can only offer a certain level of satisfactory accuracy.

Question 3: My eating habits changed after being pregnant. I only eat one type of food and I eat a lot of it. I had a diabetic test recently and the diabetes index is a little high. Will this adversely affect the fetus? If I'm diabetic during my pregnancy, will the condition persist after childbirth? This is rather worrying.

Answer 3: Diet is not the only reason for having diabetes. If your blood glucose is high, it's best to watch your diet. If blood glucose is abnormally high, a huge baby whose weight is 4kg in excess will be born. Or the fetus will be less mature than its gestational age. Diabetes arising due to pregnancy will generally disappear after childbirth.

That would be all for the information about fetal abnormalities that will guide you throughout your pregnancy.

Sandra Henderson

Editor-in-chief at Babiology and a proud mother of four passionate about sharing pregnancy and baby growth knowledges

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