Drug Use During Pregnancy

Question 1

Drugs in Pregnancy

Answer 1

-2/3 of pregnant females take > 1 med
-Both pregnancy and non pregnancy related conditions
-Drugs of abuse (etoh, caffeine)
-Safety testing cannot be done in pregnant women - requires retrospective approach (registries)
-Adverse consequences may occur in just 1 dose
-Effects are relative to period of pregnancy
(very early: death; 3-8 weeks: major morphologic malformation; 9-term - physiologic defect/ minor morphologic)
-Risk vs benefit approach
-Consequences of leaving condition untreated may be more harmful to embryo/fetus

Question 2

Effects on GI tract

Answer 2

Delayed gastric emptying
Increased transit time
Decreased stomach acidity

Question 3

Effects blood flow

Answer 3

50% increase in plasma volume

Increase in cardiac output, blood flow to uteroplacental unit, increase hepatic blood flow

Question 4

Increased GFR

Answer 4

Leads to clearance changes

Question 5

Teratogenic Effects

Answer 5

1. Fetal structural malformation

2. Other - miscarriage, still birth

Question 6

Behavioral Effects

Answer 6

Neurocognitive

Question 7

Pharmacological or toxic effects in fetus

Answer 7

• respiratory depression w opioid
• Delayed toxicity (DES exposure in utero)
• Physiologic dependency - infant

Question 8

Thalomide

Answer 8

• Used in 1950-60s for morning sickness; sedative
• Caused Phocomelia: abnormally short or missing limbs; also deformed organs
• marketed 5 years
• 10,000 children (40% died by age 1)

Question 9

FDA pregnancy risk categories

Answer 9

A: controlled human studies fail to demonstrate risk in 1st trimester, no evidence of risk in later trimesters
B: animal - failure to demonstrate risk (or show but humans don’t) human - no controlled studies
C: Animal - adverse effects on fetus or no studies done. Human - no controlled studies
D: Human - proof of fetal damage (WARNING statement on labeled drug)
x: Human or animal studies demonstrate definite risk of fetal abnormality (CONTRAINDICATION statement on drug)

Question 10

Lack of teratogenic effect in animals…

Answer 10

Doesn’t mean safety in humans

Question 11

FDA drug approvals are based on…

Answer 11

animal testing

Question 12

Pregnancy Problematic agents

Answer 12

Drugs with hormonal effects; anti cancer; antiseizure; drugs that affect thyroid; ethanol; smoking; drugs of abuse; mercury; drugs that affect cell dev/differentiation (vit a derivatives); antimicrobial; drugs that affect RAAS; Warfarin; Analgesics

Question 13

Considerations to minimize risk…

Answer 13

Education women of child bearing age
Assume any drug will reach the embryo/fetus
Weigh risk vs benefit
Is a drug needed?
Avoid substances of abuse
For known teratogens…: written informed consent, multiple forms of contraception, pregnancy test just prior to initiation