Common human birth defects were outlined including definitions, epidemiology, terminology, and causes. Screening for birth defects through ultrasound examination is important, as approximately 3% of neonates have an obvious major defect. Ultrasound can detect abnormalities in various body systems including the central nervous system, heart, gastrointestinal tract, and musculoskeletal system. Genetic testing and invasive procedures can also be used for screening high-risk pregnancies.

1. Human Birth Defects
Common congenital anomalies
Dr Elhadi Miskeen, MBBS, MD, FAIMER. Suaad Elnour, MBBS, MD, MPHE, MSc
Department of Obstetrics and Gynaecology
College of medicine, University of Bisha, Saudi Arabia

2. SLOs
Outline congenital anomalies
q Describe fetal development in relation to measures used for determination of
fetal normal development and maturity
q Outline congenital anomalies
q Differentiate between growth and development
q Trace the development of a fetus from the end of the embryonic period to
birth
q Describe measures used to determine fetal maturity
q Define the age of viability and factors affecting it in fetal pre-maturity
q List causes of congenital anomalies
q Describe the major birth defects in different body systems

3. Intrduction
• Birth defects (anomalies) are developmental disorders present at birth.
• Defects are the leading cause of infant mortality.
• They may be structural, functional, metabolic, behavioral, or hereditary.
• Birth defects are a global problem; close to 8 million children worldwide
have a serious birth defect.

4. Definition and epedemiology
• Birth defects are defined as abnormalities of structure, function, or body
metabolism that are present at birth.
• There are more than 4,000 different known birth defects ranging from
minor to serious, and although many of them can be treated or cured, they
are the leading cause of death in the first year of life.
• The American College of Obstetricians and Gynecologists (ACOG) says
that out of every 100 babies born in the USA, three have some kind of
major birth defect.

5. 90% of infants with three or more minor defects also have one or more major
defects.
Of the 3% born with clinically significant defects, multiple major defects are
found in 0.7%, and most of these infants die.
Major developmental defects are much more common in young embryos
(10%–15%), but most of them abort spontaneously during the first 6 weeks.
Chromosomal abnormalities are detected in 50% to 60% of spontaneously
aborted embryos.

6. Terminology
There are 4 clinically significant types of birth defects:
1.Malformation:
Is a morphologic defect of an organ, part of an organ, or larger region of the body that results from an
intrinsically abnormal developmental process.
2.Disruption:
Results from the extrinsic breakdown of or an interference with an originally normal developmental
process.
3.Deformation:
Is an abnormal form, shape, or position of a part of the body that results from mechanical forces.
4.Dysplasia:
Is an abnormal organization of cells in tissues and its morphologic results.

7. TERATOLOGY
• Study of abnormal development
• Teratology is the branch of embryology and pathology concerned with the
production, developmental anatomy, and the classification of malformed
embryos and fetuses.
• A fundamental concept in teratology is that certain stages of embryonic
development are more vulnerable to disruption than others

8. FETAL MATURITY
• Definition:
• Maturation is the process of achieving full development or growth.
• Growth is the process of increasing in size
• The embryo and fetus mature in utero until organ system are capable of
supporting extrauterine life
• Gestational maturity was assessed by ultrasonic measurement of fetal
biparietal diameter, and analysis constituent of amniotic fluid(creatinine,
bilirubin, and fat cells).
• Pulmonary maturation was assessed by measuring Lecithen/sphingomylin
ratio (L/S)in the amniotic fluid

9. Viability:
Viability means ability to survive or live successfully.
Fetal viability is the ability of a fetus to survive outside the uterus.
Fetal viability is generally considered to begin at 24 weeks gestational age.
There are several factors that affect the chance of survival of the baby
Gestational age (number of completed weeks of pregnancy) at the time of birth
The baby's weight
Male infants have a slightly higher risk of dying than female infants.
Health problems such as breathing problems, congenital abnormalities or malformations, and presence of
severe diseases like infection.
The mother's health (Diabetic mother)

10. Causes of birth
defects
The causes of birth defects are divided
into three broad categories:
• Genetic factors such as chromosomal
abnormalities
• Environmental factors such as drugs and
viruses
• Multifactorial inheritance (genetic and
environmental factors acting together)

11. Nondisjunction of chromosomes during the
first meiotic division of a primary oocyte
results in an abnormal oocyte with 24
chromosomes.
Subsequent fertilization by a normal sperm
produces a zygote with 47 chromosomes
(aneuploidy), which is a deviation from the
human diploid number of 46.

12. https://www.youtube.com/watch?v=dgPCDXmcQjM&t=16s

13. Common congenital
anomalies
This Photo by Unknown author is licensed under CC BY-SA-NC.

14. Turner syndrome
Female infant with
Turner syndrome (45,X).
A.. Face of the infant
with Turner.
B.. Lateral view of the
infant’s head and neck
shows a short, webbed
neck and prominent
ears.
C.. The infant’s feet
show the characteristic
lymphedema
D… Lymphedema of the
toes is a condition that
usually leads to nail
underdevelopment
(hypoplasia).

15. Turner syndrome (45,X) in a 14-year-old girl.
Features of the syndrome include short stature; a webbed neck;
absence of secondary sexual maturation; a broad chest with widely
spaced nipples; and lymphedema swelling of the hands and feet
Infants with this syndrome have defective gonadal development
(gonadal dysgenesis).
Present with primary amenorrhea

16. Turner syndrome
• Female fetus with Turner syndrome (45,X) at 16 weeks.
• Notice the excessive accumulation of watery fluid
(hydrops) and the large cystic hygroma (lymphangioma) in
the posterior head and cervical region.
• The hygroma causes the loose neck skin and webbing
seen postnatally

17. A.. Down syndrome (trisomy 21) at 16.5 weeks.
B.. single, transverse palmar flexion crease (simian crease,
arrow)
C.. faces of dizygotic male twins that are discordant for Down
syndrome (trisomy 21).
The smaller twin has Down syndrome and developed from a
zygote that contained an extra chromosome 21.
The characteristic facial features of the syndrome in this infant (
flat nasal bridge).
D.. A girl aged 2 years 6 months has Down syndrome.
Down syndrome

18. trisomy 18 syndrome
A female neonate with the trisomy 18
syndrome has growth retardation,
clenched fists with characteristic
positioning of the fingers
(second and fifth ones overlapping
the third and fourth ones), short
sternum, and narrow pelvis.

19. A female neonate with trisomy 13 syndrome
has a bilateral cleft lip, low-set and
malformed left ear, and polydactyly (extra
digits).
A small omphalocele (herniation of viscera
into umbilical cord) can be seen.
trisomy 13 syndrome

20. Klinefelter
syndrome
• A male adolescent with Klinefelter
syndrome (XXY trisomy) has breasts.
• Approximately 40% of males with
this syndrome have gynecomastia
(development of breasts) and small
testes.

21. Triploid fetus
• Triploid fetus (69 chromosomes)
• severe head-to-body disproportion.
• Triploid fetuses account for almost 20% of
chromosomally abnormal miscarriages.

22. achondroplasia
young boy with achondroplasia has:
1. short stature,
2. short limbs and fingers,
3. normal length of trunk,
4. bowed legs,
5. a relatively large head,
6. a prominent forehead,
7. and a depressed nasal bridge

24. fetal alcohol syndrome
• An infant with fetal alcohol
syndrome has
• thin upper lip,
• elongated flat nasal bridge,
• and short nose.

25. Thalidomide ingestion
• Male neonate has typically malformed limbs resulting from
thalidomide ingestion by his mother during the critical
period of limb development

26. Chorioretinitis of
congenital ocular
toxoplasmosis
Necrotizing lesion of the macula

27. Common anomalies of the
male genitalia
• Hypospadias : is an abnormality of anterior
urethral and penile development (opening of
the urethra)
• It’s the second most common urogenital birth
defect and most common anomaly of the
penis.
• Dorsal opening of the urethra called
Epispadias

28. Cont.
• Hydrocele : Occasionally the abdominal end of the processus
vaginalis remains open.
• Due to this the peritoneal fluid passes into the patent processus
vaginalis and forms accumulation called the hydrocele.

29. Hydrocele

30. Common anomalies of the female genitalia
• Didelphys (double uterus) : It is arises when
midline fusion of the müllerian ducts is
arrested, either completely or incompletely.
• The complete form is characterized by 2
hemiuteri, 2 endocervical canals with cervices
fused at the lower uterine segment

31. Cont.
• Bicornus (bicornuate)
• It is formed when the
müllerian ducts
incompletely fuse at
the level of the
uterine fundus.

32. Cont.
• Vaginal atresia : It occurs when the caudal portion of the
vagina, contributed by the urogenital sinus, fails to form.
• This caudal portion of the vagina is replaced with fibrous
tissue.
• resulting in uterovaginal outflow tract obstruction.
Normal vagina
Vaginal atresia

33. Exercise
A pregnant woman asked her physician
whether any drugs are considered safe
during early pregnancy.
Name some commonly prescribed drugs
that are considered safe to use?
What are the common drugs should be
avoided during pregnancy?

34. Drugs in pregnancy
1. Safe drugs (can be used):
In pregnancy, no medication is 100 percent safe, and even
medication that's safe for someone else to take during pregnancy
might not be safe for you.
1. Aspirin
2. Folic acid
2. Teratogenic drugs (not to use):
1. Tetracycline
2. Warfarin
3. Vitamin A

35. Screening for congenital malformation.
Identification of high-risk patients
• mother with age more than 35years
• Patient who exposed to teratogens( teratogenic drugs, radiotherapy and cytotoxic
drugs) during pregnancy
• TORCH
• Poorly controlled diabetes in early pregnancy
• Mother with previous congenitally malformed baby
• Family history of congenital malformation

36. U/S Examination
First trimester scan:-
• Measurement of nuchal
translucency.
• Identification of
anencephaly

37. Second trimester scan(
Anomaly scan)
• CNS Anomaly..eg
Ø hydrocephalus
Ø anencephaly
Ø Straberry shape skull

38. Cardiac anomaly
• most of congenital heart diseases can be diagnosed now by
u/s
ØVSD
ØFallot tetralogy.
This Photo by Unknown author is licensed under CC BY.
This Photo by Unknown author is licensed under CC BY.

39. Gastrointestinal Tract
ØEsophageal atresia
ØDuodenal atresia
ØCongenital diaphragmatic
hernia
ØGastrocasis
ØOmphalocele

40. Omphalocele

41. Polycystic kidney
disease
Posterior valve
obstruction.

42. Musculoskeletal
A chondroplasia

43. Others methods
Invasive procedures.
• Chorionic villous sampling: in the first trimester
• Amniocentesis: after the first trimester.
Laboratory test
• Measurement of alpha fetoprotein in maternal blood.
• Genetic and chromosomal analysis.

44. Summary
• Birth defects are any type of structural abnormalities that are present at birth.
• The four clinically significant types of birth defect are malformation, disruption, deformation, and
dysplasia.
• Approximately 3% of neonates have an obvious major defect.
• Birth defects may be single or multiple and have minor or major clinical significance.
• Ninety percent of infants with multiple minor defects have one or more associated major defects.
• The most common cause of congenital malformation is a Multifactorial inheritance
• The mainstay of surveillance for congenital abnormalities is the Ultrasonography
• The common risk factors for genetic disorders are: maternal or paternal age , exposure to certain
drugs, ethnicity and family history.

45. QUESTIONS

46. THANKS
This Photo by Unknown author is licensed under CC BY-NC.