EM OB 9: Comorbids in Pregnancy, part 4 (abuse, teratogens, radiation)

Question 1

remarks on opioids in pregnancy

Answer 1

although acute opioid withdrawal poses minimal maternal risk, there is significant risk to the fetus, including:
- meconium
- hypoxia
- preterm labor
- fetal demise

Illicit opioid use can cause intermittent fetal withdrawal when there’s maternal lack of access to the drug

Question 2

treatment of opioid-addicted pregnant patients

Answer 2

it is standard to refer opioid-addicted pregnant patients for supervised methadone or buprenorphine therapy for the duration of the pregnancy.

Even though methadone/buprenorphine will cause neonatal abstinence syndrome (opioid withdrawal) after birth, this is a treatable condition and carries less harm to the infant than acute opioid withdrawal in utero

Question 3

management of maternal opioid withdrawal

Answer 3

mild maternal opioid withdrawal:
clonidine 0.1 to 0.2 mg every 4 -6 hours, until signs of withdrawal resolve

severe:
may require administration of opioid agonist and admission for fetal monitoring and induction of methadone therapy

Question 4

disulfiram in pregnancy

Answer 4

Disulfiram is a potential teratogen.
There are no data on disulfiram, acamprosate, or naltrexone in pregnancy, and these agents are not recommended for alcohol abuse in pregnancy

Question 5

remarks on intimate parter violence in pregnancy

Answer 5

Institute fetal monitoring for direct or indirect blunt abdominal trauma and major multiple trauma.

Administer Rh Immunoglobulin to Rh-negative women with blunt abdominal trauma

Question 6

the classic teratogenic period is

Answer 6

2-15 weeks of gestation
teratogens early in that period affects heart or neural tube
teratogens late in that period affects the ear and palate

before week 2, exposure to a teratogen produces an all-or-non effect

Question 7

fetal A/E of fluoroquinolones

Answer 7

fetal cartilage abnormality

Question 8

fetal A/E of tetracyclines

Answer 8

fetal teeth and bone abnormalities

Question 9

fetal A/E of sulfonamides

Answer 9

fetal hemolysis
neonatal kernicterus (near term)

Question 10

fetal A/E of isotretinoin

Answer 10

hydrocephalus, deafness, anomalies

Question 11

fetal A/E of lithium

Answer 11

Ebstein’s anomaly
(malposition of two leaflets of tricuspid valve)

Question 12

fetal A/E of NSAIDs

Answer 12

prolonged use after 32 week:
oligohydramnios
constriction of fetal ductus arteriosus

Question 13

fetal A/E of thalidomide

Answer 13

phocomelia

Question 14

fetal A/E of warfarin

Answer 14

embyopathy:
nasal hypoplasia, optic atrophy

Question 15

contraindicated in breastfeeding

Answer 15

anticancer drugs
radioactive substances
amphetamines
ergotamines
statins
nitrofurantoin (for <1 month old and for those with G6PDD)

Question 16

avoid in breastfeeding unless absolutely necessary

Answer 16

chloramphenicol
tetracyclines
fluoroquinolones

Question 17

the major factor determining the degree of risk to fetus in radiologic imaging is

Answer 17

the quantity of ionizing radiation exposure during imaging

Question 18

remarks on fetal radiation effects

Answer 18

fetal exposure to low-dose radiation, defined as <5 rads (<50 mGy), does NOT increase the risk of fetal or infant death, mental defects, or growth retardation.

By using typical imaging parameters, it is unlikely that a single-phase CT scan would reach this dose level.

Question 19

considered the threshold for human teratogenesis

Answer 19

table 99-9:
100 mGy: threshold for human teratogenesis
(“more than 50 mGy”)

50 mGy: accepted as safe in pregnancy

Question 20

The fetus is most vulnerable to teratogenicity [from radiation effects] when?

Answer 20

between 3 and 15 weeks of gestation
at doses >10 rads (>100 mGy)

Question 21

effects of >10 rads (>100 mGy) in pregnancy

Answer 21

0-2 wk: possible spontaneous abortion
3-8 wk: possible malformation with increasing dose
9-15 wk: possible mental development defects with increasing dose
≥16 wk: none detectable or none

Question 22

radiation exposure to uterus/fetus in abdominal/pelvis CT

Answer 22

25-35 milligray (mGy)

Question 23

normal background radiation over 9 months

Answer 23

1 mGy

Question 24

radiation exposure to uterus/fetus in abdominal series

Answer 24

2 mGy
abdominal series = abdominal xray in 2 views

Question 25

radiation exposure to uterus/fetus in head CT

Answer 25

<0.5 mGy

Question 26

radiation exposure to uterus/fetus in chest radiography (two view, with shielding of the maternal abdomen)

Answer 26

<0.001 mGy

Question 27

lactation after imaging

Answer 27

it is advised that patients continue breastfeeding after administration of IV iodinated or gadolinum-based contrast agents.
both have low lipid solubility, and less than 1% of iodinated contrast agents and 0.04% of gadolinum-based contrast agents are excreted into breast milk

note:
Noncontrast MRI should be used unless contrast is deemed absolutely necessary given the recent concerns with gadolinum exposure to the fetus

Question 28

Condition/s most common in first trimester

Answer 28

Ovarian torsion