Pregnancy Module

1
Pregnancy Module

• Objectives
• To understand the effects of radiation on the
  fetus in doses greater than 10 Rem.
• To understand the reason for Declaring your
  pregnancy.
• To understand that low doses (lt500 mrem) do not
  cause measurable harm to the fetus.

2
Our Bodies Are Resilient

• DNA damage is most important and can lead to cell
  malfunction or death.
• Our body has 60 trillion cells
• Each cell takes a hit about every 10 seconds,
  resulting in tens of millions of DNA breaks per
  cell each year.
• BACKGROUND RADIATION causes only a very small
  fraction of these breaks ( 5 DNA breaks per cell
  each year).
• Our bodies have a highly efficient DNA repair
  mechanisms

3
Dividing Cells are the Most Radiosensitive

• Rapidly dividing cells are more susceptible to
  radiation damage.
• Examples of radiosensitive cells are
• Blood forming cells
• The intestinal lining
• Hair follicles
• A fetus

This is why the fetus has a exposure limit (over
gestation period) of 500 mrem (or 1/10th of the
annual adult limit)
4
Types of Exposure Health Effects

• Acute Dose
• Large radiation dose in a short period of time
• Large doses may result in observable health
  effects
• Early Nausea vomiting
• Hair loss, fatigue, medical complications
• Burns and wounds heal slowly
• Examples medical exposures andaccidental
  exposure to sealed sources
• Chronic Dose
• Radiation dose received over a long period of
  time
• Body more easily repairs damage from chronic
  doses
• Does not usually result in observable effects
• Examples Background Radiation andInternal
  Deposition

Inhalation
5
Pre-conception irradiation

• Pre-conception irradiation of either parents
  gonads has not been shown to result in increased
  risk of cancer or malformations in children (This
  statement is from comprehensive studies of atomic
  bomb survivors as well as studies of patients who
  had been treated with radiotherapy when they were
  children)
• Permanent Sterility
• Female gt250 rem
• Male gt350 rem

6
Fetal radiation risk

• There are radiation-related risks throughout
  pregnancy that are related to the stage of
  pregnancy and absorbed dose
• Radiation risks are most significant during
  organogenesis and in the early fetal period,
  somewhat less in the 2nd trimester, and least in
  the 3rd trimester

Most risk
Less
Least
7
Fetal radiation risk

• 0 2 Weeks The embryo is very resistant to the
  malforming effects of x rays. The embryo is,
  however, sensitive to the lethal effects of x
  rays although doses much higher than 5 rad or 50
  mSv is necessary to cause a miscarriage. 
• 3 8 Weeks The embryo is in the period of
  early embryonic development but is not affected
  with either birth defects, pregnancy loss, or
  growth retardation unless the exposure is
  substantially above the 20 rad (200 mSv)
  exposure.  

8
Fetal radiation risk

• 8 15 weeks The embryo or fetus is sensitive
  to the effects of radiation on the central
  nervous system. But here again, the exposure has
  to be very high.  Fetal doses in excess of 10 Rem
  can potentially result in some reduction of IQ
  (intelligence quotient) while fetal doses in the
  range of 100 Rem can result in severe mental
  retardation and microcephaly, (and to a lesser
  extent at 16-25 weeks). Malformations have a
  threshold of about 20 Rem or higher and are
  typically associated with central nervous system
  problems
• 16 weeks on The fetus is completely developed,
  it has become more resistant to the developmental
  effects of radiation. In fact, the fetus is
  probably no more vulnerable to many of the
  effects of radiation than the mother in the
  latter part of pregnancy.  

9
Leukaemia and cancer

• Radiation has been shown to increase the risk for
  leukaemia and many types of cancer in adults and
  children
• Throughout most of pregnancy, the embryo/fetus is
  assumed to be at about the same risk for
  carcinogenic effects as children

10
Leukaemia and cancer (contd)

• The relative risk may be as high as 1.4 (40
  increase over normal incidence) due to a fetal
  dose of 1 Rem
• For an individual exposed in utero to 1 Rem, the
  absolute risk of cancer at ages 0-15 is about 1
  excess cancer death per 1,700

11
Protecting the Embryo/Fetus

• The only way to protect the embryo/fetus from
  excess radiation is to protect the mother. When a
  mother DECLARES her pregnancy
• aBelly badge for the baby is issued
• Bioassay for radioactive material intake may be
  initiated and repeated monthly
• Pregnant woman will be administratively limited
  to work with less than 10 of the ALI activity
  (can be obtained by the RSO) to ensure an intake
  dose of less than 500 mrem.

12
Protecting the Embryo/Fetus

• Additional information is available through the
  Radiation Control Office
• You have the right to have confidential
  discussions with RSO about radiation risks to
  embryo/fetus (Even if just planning to get
  pregnant)
• If you are uncomfortable discussing this with the
  Radiation Safety Officer, arrangements may be
  made to discuss your concerns with female
  radiation health professional.

13
QUESTIONS(Select the best answer below using the
mouse)

• At what fetal radiation dose do we start to
  see physical maladies?
• A. 500 mRem
• B. 5 Rem
• C. 10 Rem
• D. 50 Rem

14

• CORRECT
• A dose of 10 Rem to the fetus is the lower
  threshold dose for malformations and learning
  disabilities

15
QUESTIONS(Select the best answer below using the
mouse)

• When is the fetus most susceptible to the
  effects of ionizing radiations?
• A 1st trimester
• B 2nd trimester
• C 3rd Trimester
• D Immediately after birth

16

• CORRECT
• Radiation risks are most significant during
  organogenesis and in the early fetal period

17
QUESTIONS(Select the best answer below using the
mouse)

• What is the maximum allowed whole body dose
  to an undeclared pregnant woman?
• A. 100 mRem
• B. 500 mRem
• C. 5 Rem
• D. 50 Rem

18

• CORRECT
• Cells are more susceptible to damage from
  ionizing radiation while undergoing mitosis.
  Most mitosis of stem cells takes place in the 1st
  trimester.

19
QUESTIONS(Select the best answer below using the
mouse)

• The annual limit of intake (ALI) for
  inhalation of 35S is 2 mCi (this is the activity
  that, if inhaled, will result in a total whole
  body dose of 5 Rem).
• What is the maximum amount of 35S that a
  declared pregnant woman can inhale and still be
  below the regulatory limit?
• A. 2 mCi
• B. 20 mCi
• C. 2 uCi
• D. 200 uCi

20

• CORRECT
• Inhalation of 200 uCi (1/10 of the ALI) will
  give a total effective whole body dose of 500
  mRem.

21
DOCUMENTING TRAINING

• Please sign and date the training form and
  click on the letter that indicates the first
  letter of your last name (ie. Farina is A)
• A. A - F
• B. G - L
• C. M - R
• D. S - Z

22
Questions ???
If you have any questions while reading the
Radiation Safety Procedures
Please Feel Free to Contact The Radiation
Safety Office
Department of Safety Risk Management Georgia
State University 11th Floor 34 Broad
Street Atlanta, Georgia 30303
413-3540
23

• INCORRECT
• PLEASE TRY AGAIN
• Return to question

24

• INCORRECT
• PLEASE TRY AGAIN
• Return to question

25

• INCORRECT
• PLEASE TRY AGAIN
• Return to question

26

• INCORRECT
• PLEASE TRY AGAIN
• Return to question

27

• Place the letter W in the last column after your
  signature Date
• Finish Training

28

• Place the letter X in the last column after your
  signature Date
• Finish Training

29

• Place the letter Y in the last column after your
  signature Date
• Finish Training

30

• Place the letter Z in the last column after your
  signature Date
• Finish Training