Safe/Unsafe Medicines in Pregnancy

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Drugs which are harmful to the fetus and are unsafe to be used in pregnancy are called teratogens and the effects are known as the teratogenic effects. When taken in the 1st trimester, some drugs can cause birth defects and miscarriages. In the 2nd trimester or 3rd trimester, there are chances of intra-uterine fetal growth retardation, defects in the placenta, preterm labor etc.

The use of any medicine during pregnancy requires careful consideration of both risks and benefits by both the mother as well as the doctor.

Most medicines cross the placenta. While some do not affect the baby, others may cause birth defects, unwanted effects around the time of birth which may or may not be reversible or may cause problems in later life.

The list of drugs here are given in the alphabetical order. The type of drug and whether it affects the baby is also mentioned.

Maternal medication Drug Type Crosses Placenta Effect on foetus Use in Pregnancy
Acetaminophen(Tylenol) Non-narcotic painkiller Yes Not known Painkiller of choice
Actifed Antihistaminic Yes Not Known Safe
Alcohol CNS Depressant Yes Fetal Alcohol Syndrome (mental retardation, growth retardation,facial abnormalitis-small eyes,drooping eyelids, wide nose) Avoided
Aluminum hydroxide/magnesium hydroxide
Antacid Yes Not known Safe
Amphetamines CNS Stimulant Yes Congenital heart disease Avoided
Ampicillin Antibiotic Yes No toxic effect Safe
Anaesthetics CNS Depressant Yes Depresses vital foetal centers Use with Care
Anti-thyroid Drugs Immuno-modulatory Yes Depresses foetal thyroid Avoid
Anti-Convulsant Drugs Controls Convulsions, epileptic attacks Yes Cleft lip/palate, congenital heart disease, abnorm- lities of the fingers, toes Avoided as far as possible
Aspirin Salicylate analgesic Yes Can cause fetal bleeding, miscarriage if dose more than 100mg per day and in last Trimester Avoided after 37 weeks
Anusol Anti-hemorrhoid No Not Known Safe
Benadryl Antihistaminic Yes Not Known Safe
Bismuth subsalicylate
(Pepto Bismol)
Antidiarrheal Yes Salicylate can cause feal bleeding Avoid
Caffeine Stimulant Yes Stillbirth, abortion, growth retardation Avoid
Mood Stabilising
Yes Neural tube defects Avoid
Cocaine CNS Depressant, effects mood Yes Miscarriage, Placental abruption, Placenta previa
Stillbirth,Growth retardation,
Chloramphenicol Antibiotic Yes Neonatal grey baby syndrome Avoid
Chloroquine Antimalarial Yes Deafness, Changes in the inner ears Avoid
Chlorthiazide Diuretic, Antihypertensive Yes Fetal or neonatal jaundice,
Chlorpheniramine maleate Antihistaminic Yes Not Known Safe
Chlorpropamide Oral Hypogycemic Yes Intrauterine or Neonatal death Avoided
Diazepam (Valium) Benzodiazepine
(Sedative, Antianxiety)
Yes Birth defects Avoided
Estrogen Female Hormone Yes Defect in testicular formation Avoid
Frusemide (Lasix) Diuretic, anti-hypertensive Yes needs more Study
Can cause higher birth weights
Only if needed
Glucocorticoids Steroid Hormone Yes Early Lung maturation
placental vessels affected
Only if needed
Isotretinoin Retinoid Yes Birth Defects,
neonatal death
Lithium Antipsychotic Drug Yes Heart Defects, Goiter Only if absolutely needed
LSD(Lysergic Acid Diethylamide) Hallucinogen Yes Low birth weight
Brain damage,
Metronidazole (oral) Antibiotic Yes Birth defects Avoid oral pills
can take vaginal ovules, ointment
Methyldopa Antihypertensive Yes None recorded Safe
Methotrexate Antihypertensive Yes neonatal death
Severe fetal anomalies
Nitrofurantoin Antibiotic Yes No fetal effects recorded Safe
Penicillin Antibiotic Yes No fetal effects recorded Safe
Prednisolone Steroid Yes Cleft lip is used in early pregnancy
Used with care
Phenobarbitone Sedative Yes Foetal bleeding (rarely) Avoided
Phenytoin Yes Multiple Fetal Anomalies Avoided
Progestogens Female Hormone Yes Masculinisation of female foetus Avoided
Promethazine (phenargan)
Reserpine Foetal nasal congestion Avoided at term
Streptomycin Fetal deafness (rarely) Used with care
Smoking (Nicotine,
other teratogens)
Yes Multiple fetal anomaies Avoided
Sulphonamides Antibiotic Yes Neonatal jaundice Avoided in the 3rd trimester
Tetracyclines Antibiotic Yes Affects bone and teeth
Thalidomides Sedative Yes Limb Deformities Avoided
Tolbutamide Multiple deformities Avoided
Triflupromazine Safe?
Trimethoprim Antibiotic Yes Avoided
Valproic Acid Yes Neural tube defects Avoided
Warfarin Yes Skeletal and limb defects,
low birth weight

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