Pregnancy Flashcards
What stage in the pregnancy is the organogenesis stage (in days)?
17-60 days
The transfer of drugs from the mother doesn’t really occur until what stage of the pregnancy?
The organogenesis stage, which is when the placenta is formed. The placenta is the main way drugs are transferred between mother and fetus.
What size drugs (in daltons) diffuse quickly into the placenta?
< 500 daltons
Drugs can have a prolonged exposure to fetuses due to what two reasons?
- drugs are weak bases (ionised)
drugs attach to embryonic proteins
What size drugs (in daltons) diffuse slowly?
500-1000 daltons
What are the only two things that can cause teratogenicity in the blastocyst stage of pregnancy?
Cytotoxic drugs and ethanol.
Category B is considered to be more safe than category C, true or false?
False.
C indicates a drug that is yet to be fully researched in humans. B indicates a drug taken by a small number of women in a study, with varying subcategories (B1, B2, B3). But because category B is about small studies, it does not hold much evidential weight. Because of this, it is more accurate to assume the B and C are inconclusively better than one another.
What size drugs (in daltons) don’t diffuse into the placenta?
> 1000 daltons
True or false, category A pregnancy scheduling is better than category C.
True.
Category A indicates a drug tested in a large number of women with no effects found on the fetus.
An altered gastric pH for pregnant women means what for drug administration?
It may alter the oral bioavailability of drugs.
Distinguish between the pregnancy subcategories B1 and B3.
B1: Study on small amount of women, no effect on fetus + no effect on pregnant animals.
B3: Study on small amount of women, no effect on fetus + some results of teratogenicity in animals.
What time frame in the pregnancy is the blastocyst stage?
0 to 16 days
Distinguish between category D and category X pregnancy scheduling.
D: The drug causes or is suspected to cause increased malformations in fetus, but may be acceptable to use despite the risk (i.e. to Rx chronic diseases in the mother).
X: Contrainidicated in those who are pregnant and those who intend to become pregnant.
The most potent teratogens are the ones that do or do not cause symptoms in the mother?
The teratogens that do not cause symptoms are the worst, because its effects will then go undetected until it has caused a significant amount of harm to the fetus.
66% of drugs are found in which pregnancy category?
<1% of drugs are found in which pregnancy category?
66% = C: Unresearched in humans. <1% = A: Researched on large cohort of pregnant women and found to be safe.
Pregnant women experience an increase or decrease in albumin concentration during pregnancy?
Decrease.
It tends to go down to about 70-80%
- Thalidomide was considered safe originally because __________
- Thalidomide has negative effects on which stage of pregnancy?
- Thalidomide has a major effect on which developmental process?
- It was tested on animals with no harmful results shown. After this, however, it became necessary to test on pregnant animals.
- Organogenesis, particularly the neural tube development.
- Angiogenesis, the formation of new blood vessels. This leads to the shortening or absence of limbs (phecomelia and amelia, respectively).
Teratogens occurring during the 17-60 day window will affect what period of the pregnancy and will produce what types of abnormalities?
Gross malformations,
Organ effects, and
Structural effects.
Smoking is considered a major teratogen, true or false?
False. Though there is uncertainty about this.
A decrease in the fetal environment pH means that what type of drugs are going to accumulate?
Weak bases.
The acidic environment will donate protons to the weak bases, making the more ionised, meaning that they then cannot easily diffuse through lipid membranes – i.e. they become trapped.
Smoking during pregnancy has three major effects, name them.
- Decreased birth weight.
- Increased chance of SIDS (x3)
- Increased chance of obstetric and perinatal complications.
True or false, the same teratogen always causes the same malformations on a fetus.
False. The same teratogen can cause different malformations if adminsitered at different times in the pregnancy.
In Australia, is drinking during pregnancy common?
Yes, 80% of mothers drink alcohol during their pregnancy.
Majority of birth defects do or do not have a causative, identifiable factor?
Majority of birth defect do not have an identifiable causative factor, approximately 70%
