Lecture on drug use during pregnancy

2021-03-19 12:00 AM

All the drugs that the mother took to reach the fetus. At birth, the new-born loses its mother's filtration system and is likely to fall into an overdose

It is known that medications taken during pregnancy affect more or less the fetus. Most drugs pass through the vegetable cake. Drug concentration in pregnancy depends on maternal factors (route of administration, rate of administration, drug metabolism, uterine-vegetable circulation), vegetable cake (diffusion rate, drug metabolism), of fetus ( liver circulation, drug metabolism in the liver).

The risks of the drug vary, depending on the stage of pregnancy. The risk of teratogenicity, fetal toxicity and cancer are the main risks in the first 3 months. After the third month, the effect of the drug is manifested by fetal pathologies, existing structural disorders (amputation), abnormalities of the organization (cyst formation), or dysfunction (delay in development spirit, movement).

Babies are at risk when their mothers take the drug. All the drugs that the mother took to reach the fetus. At birth, the newborn loses its mother's filtration system and is likely to fall into an overdose. The undesirable effects can be observed in infants such as bradycardia, hypoglycaemia due to beta-blockade drugs, secondary hypotonia due to psychotropic drugs.

Exception observed drug withdrawal syndrome. While still in the womb, the mother regularly takes medicine. After giving birth, the drug supply is suddenly cut off, leading to this syndrome.

The drugs have a very high risk of teratogenicity

Cancer medicine

All cancer drugs cause deformities, in the experiment. Only proven for people with antifolic drugs (methotrexate), for other drugs has not been proven because very rare cases of pregnancy using these drugs.

In the event of a pregnancy occurring in a woman who has been on anticancer drugs and has recovered, one must think about the risk of chromosomal abnormalities resulting from treatment and recommend early amniocentesis for testing.

In fact, when a woman is taking cancer drugs, she must be able to prevent a good pregnancy.

Medicines to cure the whole eggs

Etretimat (Tigason) and isotretinoin (Roaccutane), these drugs cause deformation of the central nervous system and skeleton. Very rarely give this drug to women of childbearing age. If it is imperative that the drug be used, the woman must be able to use a very effective contraceptive method. Use contraception 1 month before taking the drug, and until after stopping treatment for 1 month for Roaccutane and 24 months for Tigason.

The drug acts on the central nervous system

Thaldomide disaster, which is a drug of this group causing fetal deformity in the 1960s.

Epilepsy medicine

The malformation rate is 2-3 times higher than normal population when mothers use epilepsy medicine, if the drug is combined, the risk is even higher.

Trimethadione causes malformations from 20-50%.

Depakine: malformation rate is 1%, causing abnormal neural tube closure.

Dihydan and unknown barbituric drugs cause teratogenicity.

Barbituric can cause bleeding syndrome, abnormal calcium, phosphorus, decreased muscle tone and sucking reflex disturbances.

Medications for sedation

The benzodiazepine group does not have a clear teratogenic effect. It can affect the newborn with hypotonia, disturbance of the sucking reflex, and even apnea if the drug has a prolonged half-life.

In fact, pregnant women are not allowed to regularly use this drug on their own, do not stop abruptly treatment, so they should use drugs with an average half-life like seresta.


IMAO can be used during pregnancy but may cause increased blood pressure.

The imipramine drugs (Totranil, Anatranil) and amitriptyline (Elavil, Laroxyl) do not have the risk of teratogenicity, are well tolerated by pregnant women and newborns.

Drugs belonging to the phenothiazine group have a low risk of teratogenicity, which can cause an extrapyramidal syndrome in pregnant women and infants. It should be avoided when pregnant.


Distortion, especially heart disease (Ebstain), must stop treatment during pregnancy. It can be used during pregnancy in the second and third trimester, but with low dose and small expenditure dose many times. Do not take medicine while breastfeeding.

Anaesthetics, muscle relaxants

Halothane and nitrogen protoxide are teratogenic in animals, and are best avoided early in pregnancy. Local anesthesia is not contraindicated.

The muscle relaxants pass through the vegetable cake in very small amounts. In clinical practice, the time between injection and delivery during cesarean section is short enough to not be affected by the drug.

Infants are well tolerated with the muscle relaxants and anaesthesia administered to the mother. Dolargan (pethidine) passes through the vegetable cake very quickly. Dolargan can cause respiratory depression in the newborn if the time from injection to delivery is less than 2 hours.

Hormonal drugs

Androgen và progestin

Androgens and progestin (norsteroite derivatives: norethisteron, levonorgestrel, as well as danatrol) cause masculinity in the fetus. Therefore, these drugs are contraindicated during pregnancy. A small dose contained in the oral contraceptive pill is acceptable.

Anti-androgen drugs

Antiandrogen drugs such as cyproterone acetate (androcur) inhibit the masculinization of the fetus in animals. In humans do not see these effects.


Natural progesterone and its derivatives are not contraindicated.


Estrogen: It is well known that diethylstilbesterol (DES, distilbene) causes vaginal cancer in young girls whose mothers took the drug during their pregnancy. Therefore, people do not use this drug at the beginning of the pregnancy or use it to prevent pregnancy after sex. Other oestrogens are not indicated for use during pregnancy.

Birth control pills

A combination of two-component oral contraceptive pills that are used unintentionally in early pregnancy pose no risk.

Estrogen antagonists

Estrogen antagonists (clomid, clomiphen), although they do not increase the rate of malformations, must be stopped at the beginning of pregnancy.


Bromocriptine (parloden) has no adverse effects on pregnancy.


Corticoids have been reported to cause cleft palate in early pregnancy. Late in pregnancy, the drug can cause acute fetal adrenal insufficiency syndrome and intrauterine growth retardation if taken for a long time. However, corticosteroids have an effect on the maturation of the fetal lung, especially before 32 weeks.


Azathioprim (imurel) is used in combination with prednisolone. Using these two drugs for pregnant women has the risk of causing fetal growth retardation, adrenal insufficiency at birth, thymus size reduction, bone marrow reduction, leukopenia, and IgM and IgA reduction. However, in patients with severe lupus erythematosus, treatment with these two drugs reduces mortality and morbidity in newborn infants. The drug should not be discontinued in a patient who had been on therapy before pregnancy, but initiation of drug therapy should be avoided early in pregnancy.

Resistance to synthetic armor

Synthetic resistance to thyroid: will lead to congenital goiter in children, with or without functional disorders. Therefore, use only the lowest dose and still be effective and reduce the dose during labor. Radioactive iodine should not be used during pregnancy because iodine attaches to the fetal thyroid from 12 weeks, causing congenital hypothyroidism or a very large goiter, causing asphyxiation during childbirth.


Three groups of antibiotics are used as normal during pregnancy

Beta - lactamin.




Tetracycline is contraindicated because it is toxic to the mother and has consequences on the teeth and bone development of the child in the future.


Chloramphenicol is dangerous to the mother's hematopoietic organ. If taken in the days before delivery, it will accumulate in the fetus and cause fatal arrhythmias in the new-born (gray syndrome).


Aminoglycoside is contraindicated because it is toxic to the auditory organs. If you have to use treatment during pregnancy, you should use it for a short period of time (less than 1 week) together with regular monitoring of kidney function (creatinine).

Pregnant woman with tuberculosis

Pregnant women with tuberculosis: are treated with isoniazit, rifampicin, ethambutol, although it passes through vegetable cakes, but does not cause birth defects at normal therapeutic doses.


Sultamid is not used especially in late pregnancy because of hemolytic and nuclear jaundice in the newborn.

Antibiotics in the urinary tract are contraindicated during pregnancy

Flagyl, pyméthamin (malocid), trimethoprim is contraindicated in pregnant women, especially in the first quarter.

Antifungal medicine

Miconazole (Daktarin); nystatin (Mycostatin); fungizon (Amphotericin B); The econazole (Gynopevaryl), isoconazole (Fazol G) are not dangerous to the fetus, and can be administered intravaginally or intravaginally.

But griseoíuvin (Griseíuline) and ketoconazole (Nizoral) are contraindicated during pregnancy because of causing deformities, miscarriage in animals.

Anti-virus drugs: Zidovudin (Retrovin) is used during pregnancy, especially for pregnant women infected with HIV / AIDS. Aciclovir (Zovirax) is restricted to use during pregnancy, used to prevent herpes.

The drug acts on blood clotting

Coumarin group has a risk of malformations and haemorrhagic syndrome in the newborn (Warfarin causes dysplasia of cartilage, atrophy of the nose, atrophy of the optic nerve). All oral anticoagulants are contraindicated during pregnancy. Heparin or canxiparin are drugs that cannot pass through the vegetable cake and can be taken during pregnancy.

Do not use synthetic vitamin K for pregnant women and infants. Only natural vitamin K can be used, which can be used for pregnant women before labor, for babies right after birth to prevent future brain haemorrhagic complications.

Medicines for diabetes

It is known that diabetes is the source of birth defects.

Surely balancing blood sugar reduces this risk. In animals, antidiabetic drugs cause malformations. Therefore, people prefer to use insulin without antidiabetic drugs during pregnancy. Insulin does not pass through the vegetable cake.

Nonsteroidal anti-inflammatory drugs (aspirin, indomethacin, naproxen ...)

Aspirin does not cause deformity, but used too much late in pregnancy can cause neonatal bleeding due to blood clotting disorders, ductus arteriosus, old pregnancy. Therefore, it must be used with caution at the end of pregnancy. Indometacin closes the ductus arteriosus during childbirth. Must stop the drug a few days before giving birth.

It is not recommended to use drugs of this group for near term.

The risk of teratogenicity of other drugs is unknown.

Medications for high blood pressure

Taking Aldomet and Dihydralazin is no problem during pregnancy. Beta-blockers do not cause deformities, but in babies, it can cause hypoglycemia, bradycardia, bronchospasm. These undesirable effects do not limit the use of the drug if necessary, to treat high blood pressure.

Enzyme inhibitors (Captorin, Enalapril) are contraindicated because of renal failure and intrauterine growth retardation.

Calcium antagonists (Adalat, Tildiem) are used normally during pregnancy, do not cause deformities, can affect hemodynamics (cause hypotension).

Asthma medicine

Theophylline: non-teratogenic, non-toxic, can affect babies, cause tachycardia and vomiting.

Bronchodilators (Terbutalin, Isoprenalin, Ventolin) should be avoided in the first quarter. In short, pregnancy does not change the already familiar treatment of people with asthma.

Medications of the gastrointestinal tract

Anthelmintic medicine

Treatment of worms: whipworms, hookworms, worms just have to wait until after giving birth because the drugs are contraindicated.

Tapeworm: niclosamid can be used, using 4 tablets in 2 divided doses, 1 hour apart in the morning when hungry.

Roundworm: levamisol can be used from 1-2 tablets after the main meal. Other drugs are contraindicated.

Pinworms: use povanyl, 1 teaspoon for lOkg of weight, drink once, use 2 times 3 weeks apart.


People like to use metoclopramite (Primperan), promethazine (Phenergan), metopinazin (Vogalene).

H2 antagonists

Cimetidine (Tagamet) has no effect on pregnancy. Ranitidin (Azantac) is contraindicated during pregnancy.

Antimalarial medicine

Chloroquine (Nivaquin), hydroxychloroquine (Plaquenil) pass through the vegetable cake, capable of causing fetal disease (vestibular organs, cochlea). In fact, these complications are very rare and in areas with a lot of malaria, these drugs are widely used without special problems.

Our knowledge in the field of drug influence on pregnancy is not sufficient; Many times, after many years of taking the drug, it is possible to find out the unwanted effects of the drug.

Treatment in pregnant women requires special attention, as the mother's body reacts differently to foreign factors and the fetus is very susceptible to damage by these factors. It is especially dangerous if pregnant women take drugs on their own. Only use drugs when really needed, or for mothers or for the fetus, choose drugs that have been used for a long time, less toxic.