Module 3, 1
Lecture 1
NURS 5432 Module 3 , Lecture 1 : Medications and Immunizations in Pregnancy.
Medications in Pregnancy
Good afternoon students. This module, we'll be discussing pregnancy and lactation, and we're going to
start with pregnancy. So, first off, there was a shortage of reliable data regarding toxicity from drug use
during pregnancy and breastfeeding. And this is simply because third-phase clinical trials will not be
done on patients that are pregnant or breastfeeding. But in 2009, the U.S. Food and Drug
Administration launched the medication exposure in pregnancy risk evaluation program. Why is drug
therapy during pregnancy an issue? Well, two-thirds of pregnant patients take at least one medication,
or most pregnant females type more. And these medications can be taken for lots of reasons. First
being pregnancy-related problems such as nausea, constipation, and preeclampsia. But these patients
can also have chronic disorders such as hypertension, diabetes, and epilepsy. They can also have
infectious diseases or cancer, and then some moms abuse alcohol and drugs such as cocaine and
heroin.
Physiologic changes during pregnancy and their impact on drug disposition and dosing is that, during
the third trimester, renal flow is doubled and renal excretion is accelerated, also, tone and mobility of
the bowel decreases prolonging the drug effects. When a patient's taking medication during pregnancy,
they have to understand that all drugs can cross the placenta. Some cross more readily than others, but
they all cross. Adverse reactions that can occur during pregnancy are going to affect both the pregnant
patient and the fetus. Some unique effects are that heparin can cause osteoporosis, prostaglandins
stimulate uterine contractions, and then certain pain relievers used during pregnancy can depress the
respirations of the neonate.
Birth defects: Birth defects can occur from teratogenic medications, and these can cause gross
malformation, such as cleft palate, clubfoot, and hydrocephalus. Some drugs can also cause
neurobehavioral and metabolic anomalies in the fetus. Incidence and causes of congenital anomalies,
less than 1% of all birth defects are caused by drugs. And again, identification of teratogens is very
difficult. Birth defects are rare, and animal tests may not apply to humans. And again, we don't do these
clinical trials on pregnant females. As a result, only a few drugs are considered proven teratogens.
So, first off, you want to minimize the risks for teratogenesis, and that's avoiding any unnecessary drug
use, including recreational drugs, such as alcohol and cocaine. But if a pregnant female is exposed to a
teratogen, then you've got to identify the details of the exposure, what's the medication, how long have
they been taking the medication? What time during the pregnancy did this occur? And you also want to
monitor the fetus with ultrasound scans.
So, how does teratogenesis relate to the stage of development? Development occurs in three stages.
And the first is conception through week two, and then the embryonic period, which is week three
through eight. And this is the most critical period because this is when gross malformations produced
by teratogens can occur. This is when the organogenesis is taking place. And then you have fetal period,
week nine through delivery. And this is where functions are disrupted with teratogen exposure.
And this slide just shows the phases, and you can see during the embryonic phase, all the organs that are
developing and why teratogenic drugs are so dangerous during this time. In 2015, the FDA got together
and they did away with all the lettering of medications for pregnancy, and they initiated the pregnancy
lactation labeling rule. And we're going to go through this. By 2020, all prescriptions have to remove the
lettering labels.
The intent Of the PLLR is to provide the prescriber with relevant information for critical decision making
when treating pregnant and lactating women. It also should provide a more complete statement of the
known risks based on the available data. It should take into consideration the medical and disease
factors, animal data put in context of human exposure, human data added when available, and it should
explicitly state when no data are available. And this is relevant because with the old lettering categories,
the A, B, C, D, and X, might not have anything to do with how dangerous the particular medication was
, Module 3, 2
Lecture 1
for the fetus. And an example of this is birth control pills. They were category X, but they don't cause
any teratogenic effects or birth defects, really no problem in the infant, but they were category X simply
because birth control pills have no use during pregnancy. There's no indication for them during
pregnancy. And then another example is ACE inhibitors such as lisinopril. These medications can cause
fetal death, but in the old lettering category, lisinopril and ACE inhibitors were category C. So, there's no
relevancy with the lettering categories as to how dangerous the medication was. So, the PLLR is
supposed to make all of this information clearer and allow the provider to give risk and benefits and to
have a pretty decent discussion with the patient about the risks and benefits, and let them make an
informed decision as to whether or not to take a medication.
And the categories are pregnancy, lactation. And in the new category is males and females of
reproductive potential. With the pregnancy categories, the new labeling requires pregnancy exposure,
risk summary, clinical considerations, and data. And the FDA has a website with pregnancy exposure
registries on the website, that you can go to and look up, and you can enroll pregnant females in this
registry. And all providers should enroll their pregnant patients in these registries if they are taking any
medication. What these are is, they're studies that are collecting health information from women who
take prescription medications or vaccines when they are pregnant. And the information is also collected
on the newborn baby. And then it's compared to those that have not taken any medication during
pregnancy. And enrolling these patients in an exposure registry can help improve the safety information
for medicines used during pregnancy, and can be used to update the drug labeling. So again, as
providers, it's our obligation to do this. This is not mandated by the FDA, but it is available on the FDA
website.
Lactation should contain information regarding risk summary, clinical considerations, and data.
And then the category males and females of reproductive potential, this is for medications for which
pregnancy testing is indicated prior to prescribing, medications that should not be taken unless the
patient is on contraception, medications that can interfere with contraception, which we already know
many of these, such as the seizure medications, and then also any medications that can interfere with
fertility as well.
And as far as drug therapy during breastfeeding, all drugs can be excreted in the breast milk, and effects
can occur in the infant. So, here are just some helpful tips on how to decrease the risk to the infant. The
drugs need to be taken immediately after breastfeeding, avoid any drugs that have long half-lives,
choose drugs that tend to be excluded from milk and that are least likely to affect the infant, and avoid
drugs that are known to be hazardous. And this includes smoking nicotine.
Now, we'll talk about immunizations during pregnancy.
Immunizations During Pregnancy
Immunizations against preventable diseases should be administered to all women of childbearing age
prior to pregnancy, whenever possible. But immunizations administered during pregnancy are also
instrumental in protecting both the mother and the fetus from morbidity of certain infections.
And these immunizations provide passive protection to the newborn. They have good safety profile and
have not been associated with miscarriage. Viruses that are killed or inactivated can be given in
pregnancy. Live attenuated vaccines cannot be given during pregnancy. And if someone is attempting to
become pregnant and they receive a vaccine with a lot of virus in it, they should not even attempt
pregnancy for at least 28 days. And I have given the CDC website here, where you can go and look at all
the vaccines and which ones are okay to give during pregnancy.
The influenza vaccine is recommended with each pregnancy. The nasal spray should not be given
because it is a live attenuated vaccine. This is given in a single dose and it should be administered
between October and March. And it protects the mom and infant from influenza-related complications.
Lecture 1
NURS 5432 Module 3 , Lecture 1 : Medications and Immunizations in Pregnancy.
Medications in Pregnancy
Good afternoon students. This module, we'll be discussing pregnancy and lactation, and we're going to
start with pregnancy. So, first off, there was a shortage of reliable data regarding toxicity from drug use
during pregnancy and breastfeeding. And this is simply because third-phase clinical trials will not be
done on patients that are pregnant or breastfeeding. But in 2009, the U.S. Food and Drug
Administration launched the medication exposure in pregnancy risk evaluation program. Why is drug
therapy during pregnancy an issue? Well, two-thirds of pregnant patients take at least one medication,
or most pregnant females type more. And these medications can be taken for lots of reasons. First
being pregnancy-related problems such as nausea, constipation, and preeclampsia. But these patients
can also have chronic disorders such as hypertension, diabetes, and epilepsy. They can also have
infectious diseases or cancer, and then some moms abuse alcohol and drugs such as cocaine and
heroin.
Physiologic changes during pregnancy and their impact on drug disposition and dosing is that, during
the third trimester, renal flow is doubled and renal excretion is accelerated, also, tone and mobility of
the bowel decreases prolonging the drug effects. When a patient's taking medication during pregnancy,
they have to understand that all drugs can cross the placenta. Some cross more readily than others, but
they all cross. Adverse reactions that can occur during pregnancy are going to affect both the pregnant
patient and the fetus. Some unique effects are that heparin can cause osteoporosis, prostaglandins
stimulate uterine contractions, and then certain pain relievers used during pregnancy can depress the
respirations of the neonate.
Birth defects: Birth defects can occur from teratogenic medications, and these can cause gross
malformation, such as cleft palate, clubfoot, and hydrocephalus. Some drugs can also cause
neurobehavioral and metabolic anomalies in the fetus. Incidence and causes of congenital anomalies,
less than 1% of all birth defects are caused by drugs. And again, identification of teratogens is very
difficult. Birth defects are rare, and animal tests may not apply to humans. And again, we don't do these
clinical trials on pregnant females. As a result, only a few drugs are considered proven teratogens.
So, first off, you want to minimize the risks for teratogenesis, and that's avoiding any unnecessary drug
use, including recreational drugs, such as alcohol and cocaine. But if a pregnant female is exposed to a
teratogen, then you've got to identify the details of the exposure, what's the medication, how long have
they been taking the medication? What time during the pregnancy did this occur? And you also want to
monitor the fetus with ultrasound scans.
So, how does teratogenesis relate to the stage of development? Development occurs in three stages.
And the first is conception through week two, and then the embryonic period, which is week three
through eight. And this is the most critical period because this is when gross malformations produced
by teratogens can occur. This is when the organogenesis is taking place. And then you have fetal period,
week nine through delivery. And this is where functions are disrupted with teratogen exposure.
And this slide just shows the phases, and you can see during the embryonic phase, all the organs that are
developing and why teratogenic drugs are so dangerous during this time. In 2015, the FDA got together
and they did away with all the lettering of medications for pregnancy, and they initiated the pregnancy
lactation labeling rule. And we're going to go through this. By 2020, all prescriptions have to remove the
lettering labels.
The intent Of the PLLR is to provide the prescriber with relevant information for critical decision making
when treating pregnant and lactating women. It also should provide a more complete statement of the
known risks based on the available data. It should take into consideration the medical and disease
factors, animal data put in context of human exposure, human data added when available, and it should
explicitly state when no data are available. And this is relevant because with the old lettering categories,
the A, B, C, D, and X, might not have anything to do with how dangerous the particular medication was
, Module 3, 2
Lecture 1
for the fetus. And an example of this is birth control pills. They were category X, but they don't cause
any teratogenic effects or birth defects, really no problem in the infant, but they were category X simply
because birth control pills have no use during pregnancy. There's no indication for them during
pregnancy. And then another example is ACE inhibitors such as lisinopril. These medications can cause
fetal death, but in the old lettering category, lisinopril and ACE inhibitors were category C. So, there's no
relevancy with the lettering categories as to how dangerous the medication was. So, the PLLR is
supposed to make all of this information clearer and allow the provider to give risk and benefits and to
have a pretty decent discussion with the patient about the risks and benefits, and let them make an
informed decision as to whether or not to take a medication.
And the categories are pregnancy, lactation. And in the new category is males and females of
reproductive potential. With the pregnancy categories, the new labeling requires pregnancy exposure,
risk summary, clinical considerations, and data. And the FDA has a website with pregnancy exposure
registries on the website, that you can go to and look up, and you can enroll pregnant females in this
registry. And all providers should enroll their pregnant patients in these registries if they are taking any
medication. What these are is, they're studies that are collecting health information from women who
take prescription medications or vaccines when they are pregnant. And the information is also collected
on the newborn baby. And then it's compared to those that have not taken any medication during
pregnancy. And enrolling these patients in an exposure registry can help improve the safety information
for medicines used during pregnancy, and can be used to update the drug labeling. So again, as
providers, it's our obligation to do this. This is not mandated by the FDA, but it is available on the FDA
website.
Lactation should contain information regarding risk summary, clinical considerations, and data.
And then the category males and females of reproductive potential, this is for medications for which
pregnancy testing is indicated prior to prescribing, medications that should not be taken unless the
patient is on contraception, medications that can interfere with contraception, which we already know
many of these, such as the seizure medications, and then also any medications that can interfere with
fertility as well.
And as far as drug therapy during breastfeeding, all drugs can be excreted in the breast milk, and effects
can occur in the infant. So, here are just some helpful tips on how to decrease the risk to the infant. The
drugs need to be taken immediately after breastfeeding, avoid any drugs that have long half-lives,
choose drugs that tend to be excluded from milk and that are least likely to affect the infant, and avoid
drugs that are known to be hazardous. And this includes smoking nicotine.
Now, we'll talk about immunizations during pregnancy.
Immunizations During Pregnancy
Immunizations against preventable diseases should be administered to all women of childbearing age
prior to pregnancy, whenever possible. But immunizations administered during pregnancy are also
instrumental in protecting both the mother and the fetus from morbidity of certain infections.
And these immunizations provide passive protection to the newborn. They have good safety profile and
have not been associated with miscarriage. Viruses that are killed or inactivated can be given in
pregnancy. Live attenuated vaccines cannot be given during pregnancy. And if someone is attempting to
become pregnant and they receive a vaccine with a lot of virus in it, they should not even attempt
pregnancy for at least 28 days. And I have given the CDC website here, where you can go and look at all
the vaccines and which ones are okay to give during pregnancy.
The influenza vaccine is recommended with each pregnancy. The nasal spray should not be given
because it is a live attenuated vaccine. This is given in a single dose and it should be administered
between October and March. And it protects the mom and infant from influenza-related complications.
