UWORLD Chapter 48: Drug Use in Pregnancy & Lactation

What lab value confirms a pregnancy?

high human chorionic gonadotropin (hCG)

When are fetuses most susceptible to birth defects caused by teratogenic drugs?

first trimester (0-12 weeks)

What organization publishes guidelines for safe and effective drug use in pregnancy?

American College of Obstetricians and Gynecologists

What can folate deficiency during pregnancy lead to?

neural tube defects

How much folate should nonpregnant adults consume per day?

400 mcg

How much folate should pregnant women consume per day?

600 mcg DFE/day

How much calcium and vitamin D do pregnant women need to consume?

Calcium: 1000 mg/day

Vitamin D: 600 IU/day

Why were old pregnancy categories changed?

They were confusing and overly simplistic

What did the category A mean in previous pregnancy categories?

No risk of harm to fetus in the first trimester in animal and female studies

What did the category B mean in previous pregnancy categories?

Animal studies have not demonstrated a fetal risk, lack of data in humans though

What did the category C mean in previous pregnancy categories?

Animal studies have shown harm to fetus, but no well controlled studies in pregnant women. Only use if benefit outweighs risk

What did the category D mean in previous pregnancy categories?

Positive evidence of risk to human fetus, but benefits may outweigh risk in life threatening or serious diseases

What did the category X mean in previous pregnancy categories?

use in pregnancy is contraindicated

What does the 8.1 Pregnancy section of the package insert say?

• Summary of pregnancy risk that includes risk of adverse developmental outcomes.

• Includes pregnancy exposure registry information.

• Pregnant women should be encouraged to participate in these registries

What does the 8.2 Lactation section of the package insert say?

includes whether the drug/metabolites are present in human milk

What does the 8.3 Females & Males of Reproductive Potential section of the package insert say?

Includes any effects on fertility and requirements for pregnancy testing and contraception

Name a source to check if drugs are safe in pregnancy?

Briggs Drugs in pregnancy and lactation

What are key drugs & their disease states that are teratogenic in pregnancy with rarely any benefit that outweighs the risk to the baby?

- Acne: isotretinoin, topical retinoids

- Antibiotics: quinolones, tetracyclines

- Anticoagulants: Warfarin

- DLD, HF, and HTN: RAAS inhibitors, statins

- Hormones: estradiol, progesterone, raloxifene, testosterone, contraceptives

- Migraine: Dihydroergotamine, ergotamine

- Other important teratogens: Hydroxyurea, Lithium, Methotrexate, Misoprostol, NSAIDS, Paroxetine, Ribavirin, Thalidomide, Topiramate, weight loss drugs, Valproate

Other important key teratogens are...

• Hydroxyurea, Lithium, Methotrexate, Misoprostol,

• NSAIDS, Paroxetine, Ribavirin, Thalidomide, Topiramate,

• weight loss drugs, Valproate, Amiodarone, dronedarone,

• aminoglycosides, atenolol, BZDs, Dutasteride,

• Finasteride, Fluconazole, Voriconazole, Griseofulvin,

• ERAs (bosentan), leflunomide, lenalidomide, lomitapide,

• methimazole, PTU, mycophenolate, radioactive iodine,

• carbamazepine, phenobarbital, phenytoin

What 3 vaccines are recommended during pregnancy and at what weeks of gestation/conditions?

1. Tdap: weeks 27-36

2. RSV: if patient is at 32-36 weeks gestation from september-january

3. Flu: Non live, recommended during any trimester during the beginning of flu season.

What types of vaccines are contraindicated in pregnancy?

live attenuated

What is preeclampsia?

new onset of hypertension PLUS proteinuria after 20 weeks gestation

What disease states make a pregnant woman at risk for preeclampsia?

diabetes (type 1 and 2), renal disease, chronic HTN

How is preeclampsia prevented?

Low-dose (81mg) daily aspirin beginning 12-18 weeks' gestation

What is the preferred management for motion sickness, nausea, and vomiting during pregnancy?

- Lifestyle first: avoid an empty stomach, eat small frequent meals, drink plenty of water, avoid odorous foods and environmental triggers

- pyridoxine (vitamin B6) +/- doxylamine

What natural product is possible effective for motion sickness in pregnant women?

Ginger

What is the preferred management for GERD during pregnancy?

- Lifestyle first: eat smaller, more frequent meals, avoid foods that worsen GERD, elevating the head of the bed and not eating 3 hours prior to sleep

- Calcium carbonate (Tums) is the drug of choice for pregnant women

What is the preferred management for flatulence during pregnancy?

Simethicone

What is the preferred management for constipation during pregnancy?

- Lifestyle first: increase fluid intake, daily fiber, and physical activity

- fiber (psyllium, calcium polycarbophil

What is first line for cough/cold/allergy treatment in pregnant women?

cromolyn

What is second line for cough/cold/allergy treatment in pregnant women?

first generation antihistamines (chlorpheniramine is the drug of choice)

What should be avoided for cough/cold/allergy treatment in pregnant women?

liquid formulations that contain alcohol

What is first line for pain treatment in pregnant women?

acetaminophen (avoid NSAIDS including aspirin except for preeclampsia prevention

What is recommended for asthma maintenance therapy in pregnant women?

budesonide is preferred

What is recommended for asthma rescue therapy in pregnant women?

ICS-formoterol or albuterol

What dosage form is budesonide respules?

nebulizer solution

What drugs are safe to give pregnant women experiencing HTN?

Labetalol, nifedipine ER, methyldopa

What drug is preferred in pregnant women with diabetes?

insulin

What antibiotics are generally safe to use in pregnancy?

penicillins (including amoxicillin & ampicillin), cephalosporins, azithromycin, and erythromycin

What is recommended in pregnant women to treat vaginal fungal infections?

topical antifungals

What drugs are preferred for UTIs in pregnant women?

cephalexin and amoxicillin, must treat bacteria, even if asymptomatic

What drugs are alternative for UTIs in pregnant women?

Nitrofurantoin, bactrim: both considered last line in the first trimester and should not be used in the last 2 weeks of pregnancy

What can be used to diagnose toxoplasmosis?

IgG test

How is toxoplasmosis transmitted?

unpasteurized dairy products and cat feces

What is recommended in pregnant women experiencing a VTE?

LMWH preferred over UFH

What is recommended in pregnant women for VTE prophylaxis?

pneumatic compression devices +/- LMWH

What should be used for hypothyroidism in pregnant women?

levothyroxine with a 30-50% increase on normal dose

When should methimazole be used for hyperthyroidism in pregnancy?

2nd and 3rd trimester

When should PTU be used for hyperthyroidism in pregnancy?

1st trimester

What do hyperthyroidism drugs have a risk of?

liver damage

How much vitamin D is needed for partially or fully breastfed infants?

400 IU

How much iron supplementation is needed in breastfed infants after 4 months of age?

1 mg/kg daily until able to eat iron rich solid foods

What is a resource to figure out what gets passed from mother to infant in breast milk?

LactMed

What pain medications should not be used in postpartum mothers while breastfeeding? Why?

Codeine and tramadol, risk of excessive sleepiness, breathing difficulty or death in the infant

Can postpartum mothers with HIV breastfeed?

Generally not recommended for those who aren't on ART

What drugs would require a mother to pump and dump when concentrations of the drugs are highest?

amiodarone, amphetamines, ergotamines, lithium, metronidazole, phenobarbital, and statins