Drugs taken during pregnancy can affect the fetus in several ways. They may act directly on the fetus, altering the placenta's function, or causing uterine contractions. Factors like dose, timing and pharmacokinetics influence fetal effects, which range from no impact to death. While many drugs are relatively safe, careful risk-benefit assessment is needed due to variable and sometimes unknown risks. Precautions like using the lowest effective dose can help minimize harm to the developing fetus or newborn.

1. DRUG THERAPYDRUG THERAPY
DURING PREGNANCYDURING PREGNANCY

2. Drugs that a pregnant woman takes canDrugs that a pregnant woman takes can
affect theaffect the fetus in several ways:fetus in several ways:
 1- They can act directly on the fetus causing damage1- They can act directly on the fetus causing damage
or abnormal development leading to birth defects oror abnormal development leading to birth defects or
death.death.
 Drugs can also alter the function of the placentaDrugs can also alter the function of the placenta
usually by constricting blood vessels and reducing theusually by constricting blood vessels and reducing the
blood supply of oxygen and nutrients to the fetus fromblood supply of oxygen and nutrients to the fetus from
mother and thus resulting in a baby that is underweightmother and thus resulting in a baby that is underweight
and underdevelopedand underdeveloped..
 Moreover they can cause the muscles of the uterus toMoreover they can cause the muscles of the uterus to
contract forcefully; indirectly injuring the fetus bycontract forcefully; indirectly injuring the fetus by
reducing the blood supply or triggering pre-term laborreducing the blood supply or triggering pre-term labor
and delivery.and delivery.

3. PHARMACOKENETICS OFPHARMACOKENETICS OF
DRUGS DURINGDRUGS DURING
PREGNANCYPREGNANCY
 ABSORPTION- DECREASED GIABSORPTION- DECREASED GI
MOTILITY CAUSES INCREASED DRUGMOTILITY CAUSES INCREASED DRUG
ABSORPTION.ABSORPTION.
 DISTURBUTION- PROTIEN BINDING ISDISTURBUTION- PROTIEN BINDING IS
DECREASED CAUSES INCREASEDDECREASED CAUSES INCREASED
FREE DRUG TO BE AVAILABLE.FREE DRUG TO BE AVAILABLE.
 METABOLISM-INCREASED HEPATICMETABOLISM-INCREASED HEPATIC
METABOLISM OCCURS FOR SOMEMETABOLISM OCCURS FOR SOME
DRUGSDRUGS

4. PHARMACOKENETICSPHARMACOKENETICS
 EXCRETION- IN THE 3RD TRIMESTEREXCRETION- IN THE 3RD TRIMESTER
INCREASED RENAL BLOOD FLOW &INCREASED RENAL BLOOD FLOW &
GFR CAUSES SOME DRUGS TOGFR CAUSES SOME DRUGS TO
CLEAR THE BODY FASTER.CLEAR THE BODY FASTER.

5. DRUG THERAPY IN THEDRUG THERAPY IN THE
CHILDBEARING CLIENTCHILDBEARING CLIENT
 REQUIRES SPECIALREQUIRES SPECIAL
CONSIDERATIONSCONSIDERATIONS
 IS CHALLENGING TOIS CHALLENGING TO
PROVIDEPROVIDE
EFFECTIVEEFFECTIVE
Treatment WHILETreatment WHILE
AVOIDING HARM TOAVOIDING HARM TO
EMBRYO, FETUS OREMBRYO, FETUS OR
NEONATENEONATE
 CENTERED ONCENTERED ON
RISK/BENEFITRISK/BENEFIT
RATIORATIO
 EFFECTS OFEFFECTS OF
DRUGS NOTDRUGS NOT
ALWAYS KNOWNALWAYS KNOWN

6. ANY DRUG TAKEN BY
THE PREGNANT ORTHE PREGNANT OR
BREAST FEEDINGBREAST FEEDING
CLIENT HAS THECLIENT HAS THE
POTENTIAL TOPOTENTIAL TO
REACH THE FETUSREACH THE FETUS
BY WAY OFBY WAY OF
MATERNALMATERNAL
CIRCULATION ORCIRCULATION OR
NEONATE BY WAY OFNEONATE BY WAY OF
BREASTMILKBREASTMILK

7. EFFECTS OF DRUGSEFFECTS OF DRUGS
ON THE EMBRYO,ON THE EMBRYO,
FETUS, OR NEONATEFETUS, OR NEONATE
 MAY VARY---MAY VARY---
 NO EFFECT.NO EFFECT.
 LITTLELITTLE
 SERIOUS- FETAL TOXICITYSERIOUS- FETAL TOXICITY
 SPONTANEOUS ABORTIONSPONTANEOUS ABORTION
 DEATHDEATH
 FETAL MALFUNCTIONFETAL MALFUNCTION
 FETAL MALFORMATIONS.FETAL MALFORMATIONS.

8. RECENT STUDIESRECENT STUDIES
 75% OF PREGNANT CLIENTS USE75% OF PREGNANT CLIENTS USE
3-10 DIFFERENT DRUGS3-10 DIFFERENT DRUGS
(PRESCRIPTION OR OTC’S) OTHER(PRESCRIPTION OR OTC’S) OTHER
THAN VITAMINS/MINERALTHAN VITAMINS/MINERAL
SUPPLEMENTS DURING THEIRSUPPLEMENTS DURING THEIR
PREGNANCY.PREGNANCY.
 OTC’S WERE USED 4 TIMES THATOTC’S WERE USED 4 TIMES THAT
OF PRESCRIPTION DRUGS.OF PRESCRIPTION DRUGS.

9. DRUG LEVELS IN THEDRUG LEVELS IN THE
FETUS REACHED 50-FETUS REACHED 50-
100% OF THE100% OF THE
MATERNAL BLOODMATERNAL BLOOD
LEVELSLEVELS

10. Inadvertent ExposureInadvertent Exposure
 1/2 of pregnancies unplanned1/2 of pregnancies unplanned
 Teratogenic potential should beTeratogenic potential should be
considered and explained to women ofconsidered and explained to women of
childbearing age at time drug ischildbearing age at time drug is
prescribedprescribed
– <50% of women know they are pregnant by<50% of women know they are pregnant by
44thth
week and ~20% still don’t know by 8week and ~20% still don’t know by 8thth
weekweek

11. ComplianceCompliance
 Pregnant women tend to complyPregnant women tend to comply
less than optimally with drugless than optimally with drug
therapytherapy
 39% of women reported39% of women reported
noncompliance predominantlynoncompliance predominantly
due to hesitation to use drugsdue to hesitation to use drugs
during pregnancyduring pregnancy

12. BIRTH DEFECTSBIRTH DEFECTS
 INCIDENCE OF MAJOR STRUCTURALINCIDENCE OF MAJOR STRUCTURAL
DEFECTS (ABNORMALITIES) ISDEFECTS (ABNORMALITIES) IS
ABOUT 6% OF ALL PREGNANCIES.ABOUT 6% OF ALL PREGNANCIES.
 3% ARE CAUSED BY DRUGS OR3% ARE CAUSED BY DRUGS OR
ENVIRONMENTALENVIRONMENTAL
fACTORS/EXPOSUREfACTORS/EXPOSURE
 3% HAVE UNKNOWN CAUSES3% HAVE UNKNOWN CAUSES

13. BIRTH DEFECTSBIRTH DEFECTS
 1/2 OF THE BIRTH DEFECTS ARE1/2 OF THE BIRTH DEFECTS ARE
OBVIOUS AT BIRTH.OBVIOUS AT BIRTH.
 1/2 OF THE BIRTH DEFECTS1/2 OF THE BIRTH DEFECTS
AREN’T DISCOVERED UNTIL LATERAREN’T DISCOVERED UNTIL LATER
IN LIFE OR DISCOVERED DURINGIN LIFE OR DISCOVERED DURING
AN AUTOPSYAN AUTOPSY
 INCIDENCE OF MINORINCIDENCE OF MINOR
STRUCTURAL ABNORMALIES ISSTRUCTURAL ABNORMALIES IS
NOT KNOWN.NOT KNOWN.

15. TERATOGENICTERATOGENIC
TERATOGENESISTERATOGENESIS
 TERAS-”MONSTER”TERAS-”MONSTER”
 GENSIS-”PRODUCING”GENSIS-”PRODUCING”
 BIRTH DEFECTS/DISTORTION OFBIRTH DEFECTS/DISTORTION OF
GROSS ANATOMY.GROSS ANATOMY.
 EXAMPLES- CLEFT LIP/PALATE,EXAMPLES- CLEFT LIP/PALATE,
CLUBFOOT, NEURAL TUBALCLUBFOOT, NEURAL TUBAL
DEFECTS, MISSING ORDEFECTS, MISSING OR
MALFORMED LIMBS/FINGERS.MALFORMED LIMBS/FINGERS.

16. TERATOGENICTERATOGENIC
 ALSO-BEHAVORIAL AND/ ORALSO-BEHAVORIAL AND/ OR
BIOCHEMICAL ABNORMALITIES.BIOCHEMICAL ABNORMALITIES.
 TERATOGENESIS MAYBE DIRECTTERATOGENESIS MAYBE DIRECT
MALFORMATIONS OFMALFORMATIONS OF
STRUCTURESSTRUCTURES
 OR INDIRECT-SUCH ASOR INDIRECT-SUCH AS
INTERFERING WITH OINTERFERING WITH O22 OROR
NUTRIENTS.NUTRIENTS.

17. FETAL EFFECTS FROMFETAL EFFECTS FROM
DRUGS DEPEND ONDRUGS DEPEND ON
SEVERAL FACTORSSEVERAL FACTORS
 TIME- WHEN DRUG IS TAKEN INTIME- WHEN DRUG IS TAKEN IN
PREGNANCY.PREGNANCY.
1.1. PREIMPLANTATIONPREIMPLANTATION PERIOD; fromPERIOD; from
CONCEPTION TO 2 WEEKCONCEPTION TO 2 WEEK
 HIGH DOSE- MAYBEHIGH DOSE- MAYBE
LETHAL/DEATH/ABORTIONS.LETHAL/DEATH/ABORTIONS.
 LOW DOSE-MAYBE NOTHING.LOW DOSE-MAYBE NOTHING.

18. 2.2. EMBRYONIC PERIOD-3-8EMBRYONIC PERIOD-3-8 WEEKSWEEKS
*FIRST TRIMESTER* 2-9 weeks*FIRST TRIMESTER* 2-9 weeks
GROSS MALFORMATIONSGROSS MALFORMATIONS
3.3. FETAL PERIODFETAL PERIOD 9-40 WEEKS (TERM)9-40 WEEKS (TERM)
FUNCTION PROBLEMS RATHERFUNCTION PROBLEMS RATHER
THAN GROSS ANATOMYTHAN GROSS ANATOMY
 LEARNING DEFICITS and ORLEARNING DEFICITS and OR
BEHAVORIAL ABNORMALIESBEHAVORIAL ABNORMALIES

20. Known TeratogensKnown Teratogens
 Alcohol (Ethanol)Alcohol (Ethanol)
 CarbamazepineCarbamazepine
 CytotoxicCytotoxic
chemotherapychemotherapy
 DESDES
 Isotretinoin andIsotretinoin and
EtretinateEtretinate
 LithiumLithium
 MethimazoleMethimazole
 MisoprostolMisoprostol
 PhenytoinPhenytoin
 ThalidomideThalidomide
 TrimethoprimTrimethoprim
 Valproic AcidValproic Acid
 WarfarinWarfarin

21. Drug pregnancyDrug pregnancy
categoriescategories
 Category ACategory A: Adequate and well-controlled: Adequate and well-controlled
studies have failed to demonstrate a riskstudies have failed to demonstrate a risk
to the fetus in the first trimester ofto the fetus in the first trimester of
pregnancy (and there is no evidence ofpregnancy (and there is no evidence of
risk in later trimesters).risk in later trimesters).
 Category BCategory B: Animal reproduction studies: Animal reproduction studies
have failed to demonstrate a risk to thehave failed to demonstrate a risk to the
fetus and there are no adequate and well-fetus and there are no adequate and well-
controlled studies in pregnant women.controlled studies in pregnant women.

22.  Category CCategory C: Animal reproduction studies have: Animal reproduction studies have
shown an adverse effect on the fetus and thereshown an adverse effect on the fetus and there
are no adequate and well-controlled studies inare no adequate and well-controlled studies in
humans, but potential benefits may warrant usehumans, but potential benefits may warrant use
of the drug in pregnant women despite potentialof the drug in pregnant women despite potential
risks.risks.
 Category DCategory D: There is positive evidence of: There is positive evidence of
human fetal risk based on adverse reaction datahuman fetal risk based on adverse reaction data
from investigational or marketing experience orfrom investigational or marketing experience or
studies in humans, but potential benefits maystudies in humans, but potential benefits may
warrant use of the drug in pregnant womenwarrant use of the drug in pregnant women
despite potential risks.despite potential risks.

23.  Category X:Category X: Studies in animals orStudies in animals or
humans have demonstrated fetalhumans have demonstrated fetal
abnormalities and/or there is positiveabnormalities and/or there is positive
evidence of human fetal risk based onevidence of human fetal risk based on
adverse reaction data fromadverse reaction data from
investigational or marketing experience,investigational or marketing experience,
and the risks involved in use of the drugand the risks involved in use of the drug
in pregnant women clearly outweighin pregnant women clearly outweigh
potential benefits.potential benefits.
 Category N:Category N: FDA has not classified theFDA has not classified the
drug.drug.

24. Penicillins andPenicillins and
CephalosporinsCephalosporins
 Amoxicillin and cephalosporinsAmoxicillin and cephalosporins
(category B) are considered safe to use(category B) are considered safe to use
during pregnancyduring pregnancy
 No increased risk of malformations withNo increased risk of malformations with
amoxicillin/clavulanic acid (Augmentin)amoxicillin/clavulanic acid (Augmentin)
in 2 studies. (category B)in 2 studies. (category B)

25.  Erythromycin and azithromycin: CategoryErythromycin and azithromycin: Category
BB
 Clarithromycin: Category CClarithromycin: Category C
 Clindamycin: category BClindamycin: category B
 Ciprofloxacin: category C: possibility ofCiprofloxacin: category C: possibility of
joint malformation (seen only in children)joint malformation (seen only in children)
 Tetracyclines: category DTetracyclines: category D

26. MetronidazoleMetronidazole
 Mutagenic in bacteria andMutagenic in bacteria and
carcinogenic in animalscarcinogenic in animals
 Small number of reports raisedSmall number of reports raised
suspicion of teratogenic effectsuspicion of teratogenic effect
 Category BCategory B

27.  Aminoglycosides: ototoxicity: can causeAminoglycosides: ototoxicity: can cause
deafnessdeafness
 Sulfonamides: jaundice when given late inSulfonamides: jaundice when given late in
pregnancy and possible brain damagepregnancy and possible brain damage
(kernictrus).(kernictrus).

28. Local Anesthetics -Local Anesthetics -
LidocaineLidocaine
 Considered relatively safe for useConsidered relatively safe for use
during pregnancy (category B)during pregnancy (category B)
 Mepivacane (category C)Mepivacane (category C)

29. EpinephrineEpinephrine
 Potential to compromisePotential to compromise
uterine blood flowuterine blood flow
 Studies have failed toStudies have failed to
demonstrate adverse fetaldemonstrate adverse fetal
effectseffects
 Low doses used in dentistryLow doses used in dentistry
 Avoid inadvertentAvoid inadvertent
intravascular injectionintravascular injection
 Category CCategory C

30. AcetaminophenAcetaminophen
 ““Analgesic of choice” category B.Analgesic of choice” category B.

31. NSAIDSNSAIDS (including Aspirin and(including Aspirin and
cox II-inhibitors)cox II-inhibitors)
 Increased risk of miscarriage?Increased risk of miscarriage?
 Avoid use during late pregnancy (3Avoid use during late pregnancy (3rdrd
trimester)trimester)
↑↑ BleedingBleeding
– Inhibition of prostaglandin synthesisInhibition of prostaglandin synthesis
 Prolonged labourProlonged labour
 Constriction of ductus arteriosusConstriction of ductus arteriosus
 Category C but in last trimester category DCategory C but in last trimester category D

32. NarcoticsNarcotics
(Codeine, Oxycodone, etc.)(Codeine, Oxycodone, etc.)
 Don’t appear toDon’t appear to ↑↑ risk of birthrisk of birth
defectsdefects
 Low dose short-term regimensLow dose short-term regimens
acceptable. Category Cacceptable. Category C
If used for long period: category DIf used for long period: category D
 Respiratory depressionRespiratory depression
 Neonatal withdrawalNeonatal withdrawal

33. Nitrous Oxide (NNitrous Oxide (N22 O) withO) with
OO22 Use during pregnancy somewhatUse during pregnancy somewhat
controversialcontroversial
 Inhibits methionine synthetase which canInhibits methionine synthetase which can
affect DNA synthesisaffect DNA synthesis
 Teratogenic in animalsTeratogenic in animals
 Single brief maternal exposure duringSingle brief maternal exposure during
pregnancy unlikely to pose a substantialpregnancy unlikely to pose a substantial
teratogenic riskteratogenic risk
 Minimize prolonged use (< 30 minutes, atMinimize prolonged use (< 30 minutes, at
least 50% Oleast 50% O22))

34. BenzodiazepinesBenzodiazepines
 Category DCategory D
 Cause cleft palatCause cleft palat

35. RadiationRadiation
 In most cases of diagnostic x-In most cases of diagnostic x-
rays the fetal radiation exposurerays the fetal radiation exposure
is much below the threshold doseis much below the threshold dose
of 5 to 10 radof 5 to 10 rad

36. Average Fetal Exposure DoseAverage Fetal Exposure Dose
(mrad)(mrad)
CXR <5
Abdomen 200-289
UGI 48-360
IVP 358-880
Dental 0.01
• Fetal exposure dose from a full mouth seriesFetal exposure dose from a full mouth series
(18 films) or panoramic radiograph is <1/1000(18 films) or panoramic radiograph is <1/1000
value of concernvalue of concern
• 40-fold < naturally occurring background40-fold < naturally occurring background
radiationradiation

37. American DentalAmerican Dental
AssociationAssociation
 Abdominal exposure during dentalAbdominal exposure during dental
radiography is negligibleradiography is negligible
 Recommend that pregnant womenRecommend that pregnant women
postpone elective dental x-rays untilpostpone elective dental x-rays until
after delivery; however, there are timesafter delivery; however, there are times
when an x-ray may be required duringwhen an x-ray may be required during
pregnancy to help diagnose and treatpregnancy to help diagnose and treat
oral disease (thyroid collar and apron)oral disease (thyroid collar and apron)

41. Breast feeding drugBreast feeding drug
administrationadministration
 Most drugs that go into the body will also go into theMost drugs that go into the body will also go into the
milk.milk.
 so before any medication is taken, consideration ofso before any medication is taken, consideration of
its effect on baby and whether or not it has anyits effect on baby and whether or not it has any
effects on lactation needs to be done.effects on lactation needs to be done.
 While most medications are safe to take whileWhile most medications are safe to take while
breastfeeding, it’s wise to talk to the doctor beforebreastfeeding, it’s wise to talk to the doctor before
taking.taking.
 Some drugs do not harm the baby, but may affectSome drugs do not harm the baby, but may affect
the milk volume by suppressing the milk-makingthe milk volume by suppressing the milk-making
hormones.hormones.

42. The effect of the drug willThe effect of the drug will
depend on:depend on:
••The route of administration:The route of administration:
Topical medications (skin creams) and medicationsTopical medications (skin creams) and medications
inhaled or applied to the eyes or nose reach the milkinhaled or applied to the eyes or nose reach the milk
in lesser amounts and more slowly than other routesin lesser amounts and more slowly than other routes
and are almost always safe for nursing mothers.and are almost always safe for nursing mothers.
oral medications take longer to get into the milk thanoral medications take longer to get into the milk than
IV and IM routesIV and IM routes

43. ••The amountThe amount taken: The higher the dosage, thetaken: The higher the dosage, the
more the drug transfers into milk.more the drug transfers into milk.
How often you take the drug:How often you take the drug: Medications taken 30Medications taken 30
to 60 minutes before you feed are likely to be ato 60 minutes before you feed are likely to be a
peak blood levels when your baby nurses.peak blood levels when your baby nurses.
Your baby’s age and health:Your baby’s age and health: Premature infantsPremature infants
have immature kidney and liver functions and mayhave immature kidney and liver functions and may
have trouble processing and eliminating even smallhave trouble processing and eliminating even small
quantities of drugs that might not cause problemsquantities of drugs that might not cause problems
for larger, full-term infantsfor larger, full-term infants
however, even full-term baby’s protective metabolichowever, even full-term baby’s protective metabolic
systems are not fully developed for the first week ofsystems are not fully developed for the first week of
life.life.

44. Babies who are seriously ill, especially those withBabies who are seriously ill, especially those with
immune system disorders, may have less ability toimmune system disorders, may have less ability to
metabolize the same amount of medication than ametabolize the same amount of medication than a
healthy baby.healthy baby.
••The frequency and volume of feedings:The frequency and volume of feedings: The baby whoThe baby who
is nursing once or twice a day, and is supplemented theis nursing once or twice a day, and is supplemented the
rest of the time, will receive less of a drug than the babyrest of the time, will receive less of a drug than the baby
who is exclusively breastfed and may nurse 11 times awho is exclusively breastfed and may nurse 11 times a
day.day.
••Duration of drug therapy:Duration of drug therapy: A medication taken for weeksA medication taken for weeks
or months may have a greater impact on nursing thanor months may have a greater impact on nursing than
one taken for just a few days.one taken for just a few days.

45. ••The type of medication:The type of medication: Characteristics such as theCharacteristics such as the
molecular weight, how fat soluble the drug is, andmolecular weight, how fat soluble the drug is, and
how long it takes for it to be eliminated from yourhow long it takes for it to be eliminated from your
system, or it’s half-life, all affect how much of thesystem, or it’s half-life, all affect how much of the
drug is transferred into your milk.drug is transferred into your milk.
Aspirin in large doses – May cause bleeding orAspirin in large doses – May cause bleeding or
Reye’s syndrome in theReye’s syndrome in the fetusfetus
 Chloramphenicol – Can cause diarrhea, boneChloramphenicol – Can cause diarrhea, bone
marrow suppression and gray baby syndromemarrow suppression and gray baby syndrome

46.  Tetracyclines - the transfer of tetracyclines
into breast milk is low but they are usually
avoided due to the possible risks of
inhibiting bone growth or causing dental
staining.
 Fluoroquinolones should also be avoided
in breastfeeding as they have been
reported to cause arthropathies in
immature animals.
 Sulphonamides such as
sulphamethoxazole are unlikely to be
problematical in high bilirubin and glucose

47. MetronidazoleMetronidazole
 Use during lactation controversialUse during lactation controversial
 Excreted into breast milk in relatively largeExcreted into breast milk in relatively large
amountsamounts
 Concern expressed with respect to possibleConcern expressed with respect to possible
mutagenic effectsmutagenic effects
 No reports of adverse effects in nursing infantsNo reports of adverse effects in nursing infants
 In conventional doses compatible withIn conventional doses compatible with
breastfeedingbreastfeeding
 If taken in single large dose breastfeeding mayIf taken in single large dose breastfeeding may
be temporarily withheld for 24 hoursbe temporarily withheld for 24 hours

48. CodeineCodeine
 Intermittent difficulty breastfeedingIntermittent difficulty breastfeeding
and lethargyand lethargy
 Blood morphine concentration veryBlood morphine concentration very
highhigh

49. BenzodiazepinesBenzodiazepines
 Milk levels of benzodiazepines notMilk levels of benzodiazepines not
excessive but rarely sedation has beenexcessive but rarely sedation has been
reported in breastfed infantsreported in breastfed infants
 If sedative required, shorter half-lifeIf sedative required, shorter half-life
drugs such as lorazepam anddrugs such as lorazepam and
midazolam preferredmidazolam preferred
 Long term exposure not recommendedLong term exposure not recommended

50. Drugs considered to be safeDrugs considered to be safe
 AcetaminophenAcetaminophen
 IbuprofenIbuprofen
 LidocaineLidocaine
 Penicillins and Cephalosporins, and macrolidesPenicillins and Cephalosporins, and macrolides