# Presentation: 125087

## Better Safe Than Sorry:The Biological Basis of Fetal Alcohol Syndrome and otherAlcohol-Related Birth Defects

## When a mother drinks, her unborn child is exposed to alcohol.

**When a mother drinks, her unborn child is exposed to alcohol.**

## Alcohol-Related Birth Defects Include:

**Fetal Alcohol Syndrome** **(FAS)**
- 	which is characterized by						1.  central nervous system problems 			2.  low birth weight and height
- 			3.  typical facial features
**Fetal Alcohol Effects** **(FAE)****	****	****	**which result from maternal alcohol abuse but are found in the absence of the full-blown syndrome

## The facial features ofFetal Alcohol Syndrome are:

**Small eyelid openings (palpebral fissures)**
**Short, upturned nose**
**Long upper lip (from nose to mouth) with a thin red border and a deficient central groove (philtrum) **
**Reduced size of the head (microcephaly)**

## FAS

**NORMAL**

## FAS

**     ****Full-blown fetal alcohol syndrome (FAS) ****   represents only the ****   “tip of the iceberg”         ****       relative to all****alcohol-related birth****        defects (ARBDs).**

- ARBDs

## MATERNAL ALCOHOL ABUSE IS THE LEADING KNOWN CAUSE OF MENTAL RETARDATION IN THE WESTERN WORLD

## Children with alcohol-related birth defects typically have:

**attention deficits**
**language difficulties**
**learning disabilities**
**impulsive behavior**
**poor judgment**

## Cross-section

- Whole brain

- cerebral hemispheres

- cerebellum

- corpuscallosum

-     **PRENATAL ALCOHOL EXPOSURE CAN PERMANENTLY **
**DAMAGE THE BRAIN, AFFECTING IMPORTANT STRUCTURES **
**SUCH AS THE CEREBELLUM AND CORPUS CALLOSUM,**
**AS WELL AS SPECIFIC CELL POPULATIONS IN MANY OTHER **
**REGIONS OF THE BRAIN**

## Visualization of the brain of a normal individual (A) and two with FAS (B,C) shows permanent loss of the tissue indicated by the arrows (portions of the corpus callosum).

- Images courtesy of Dr. S. Mattson

**Similarities in mouse and human embryogenesis provide opportunities  to study the effects **
**of alcohol on development.**

- 5 mm.

##  The facial features of Fetal Alcohol Syndrome 

- Narrow forehead

- Short palpebral fissures

- Small nose

- Small midface
- Long upper lip with
- deficient philtrum

- child with FAS

- normal

- alcohol-exposed

- mouse fetuses

** ****The facial features of Fetal Alcohol Syndrome **
**  ****can be seen in both a child and a mouse fetus **
**that were exposed to alcohol during development.**

## The amount and timingof maternal alcohol use determine the type and extent of resulting birth defects.

**The amount and timing****of maternal alcohol use determine the type and extent of resulting birth defects.**

## Slide 14

## ALCOHOL KILLS SPECIFIC CELLS 

**ALCOHOL KILLS SPECIFIC CELLS **
**     ****IN THE DEVELOPING BRAIN**

**Arrows surround a portion of the brain of a mouse **
**embryo (viewed from the back) that is at a develop-**
**mental stage corresponding to a 22-23 day human.**

**     ****Cells killed by alcohol in the brain of a mouse **
** ****embryo (at a comparable stage of development **
**to that on the left) have taken up a dark blue stain.**

## that have taken up a dark blue stain. 

**Developing**
**brain and**
**face **

**Heart**

**Mouse embryo (viewed from**
** ****the front) at a stage corresponding **
**to a 22-23 day old human.**

**A close-up view of an alcohol-exposed **
**mouse embryo shows cells killed by alcohol**
**that have taken up a dark blue stain.**** **

**EYE**

**EYE**

- A

- C

- B

- D

**MOUTH**

**MOUTH**

**NOSTRILS**

**NOSTRILS**

** ****MIDLINE STRUCTURES OF THE FACE AND BRAIN ARE  DEFICIENT  IN**
**ALCOHOL-EXPOSED MOUSE EMBRYOS AND IN  INDIVIDUALS WITH FAS**

**THE FACE OF A CHILD**
**WITH FULL-BLOWN FAS**
**HAS FEATURES THAT**
**CAN BE CAUSED BY **
**DAMAGE TO MIDLINE**
**STUCTURES.**

**COMPARISON OF THE FACE (A) AND INTERIOR OF THE BRAIN (B) OF A NORMAL **
**MOUSE EMBRYO AND ONE DAMAGED BY ALCOHOL (C&D) SHOWS THAT THE NOSTRILS **
**ARE ABNORMALY POSITIONED (C) AND THE BRAIN IS MISSING MIDLINE STRUCTURES (D).**

## ALCOHOL KILLS SPECIFIC CELLS      IN THE DEVELOPING BRAIN

**A cut made through the**
** ****area outlined by arrows**
**provides a view of the inside of the brain of a **
**                                    ****10 day mouse embryo **
**                                   ****(corresponding to a 28 day human)**

**    ****Cells killed by **
**alcohol** **have taken up **
**    ****dark blue stain**** **

**The pattern of cell death varies **
**with the stage of development.**

## EXPOSURE TO ALCOHOL 

**EXPOSURE TO ALCOHOL **
**DURING DEVELOPMENT**
**CAN CAUSE DAMAGE **
**TO ORGANS AND REGIONS **
**OTHER THAN THE BRAIN**

## By the ninth week of development the human fetus is about 24mm. long. Damage caused by alcohol to the brain at this time and until birth can result in abnormal brain function. 

## Excessive alcohol exposure can causedamage during all stages ofprenatal development.

**Pre-implantation:**** ****first 2 weeks**
**Embryonic****:**** ****3-8 weeks after conception**
**Fetal****: from week 9 until birth**

##  Alcohol can cause permanent damage to a baby before most women realize they are pregnant. 

## Alcohol-related	birth defects		last a lifetime.

**Alcohol-related****	****birth defects****	****	****last a lifetime.**

## Alcohol-related birth defects are expensive:

**Alcohol-related birth defects are expensive:**

**Monetarily — for treatment, ****care****, and lost productivity. Costs are between $800,000 - $2 million over a lifetime for each individual with FAS.**
**Socially — relative to delinquency and to emotional drains on involved families.**

## ???How much is too much???

**???****How much is too much****???**

## How much alcohol is in a drink?

**12 oz beer   =    5 oz wine   =   shot of liquor**
**Each contains the same amount of alcohol**

-  in a mixed drink

## Some drinks contain more than a “serving” of alcohol

**Some drinks contain more than a “serving” of alcohol**

## NO ONE KNOWS WHAT A 

**“****SAFE” AMOUNT OF**
**ALCOHOL CONSUMPTION **
**DURING PREGNANCY**
** ****MAY BE.**
** **

## Health advisories urge women who     are planning             pregnancy    or are pregnant not to drink alcohol.

##      Despite warnings, frequent drinking among pregnant women               appears to be increasing.

-       Frequent drinking is defined as 7
- or more drinks per week or 5 or more
-        drinks on at least one occasion.

##     ALCOHOL-RELATED 

**    ****ALCOHOL-RELATED **
**        ****BIRTH DEFECTS **
**    ****ARE PREVENTABLE**