Download Abnormalities of conceptus` development. Multifetal pregnancy

BUKOVINIAN STATE MEDICAL UNIVERSITY
“Approved”
on methodological meeting
of Department of Obstetrics and Gynecology
with course of Infant and Adolescent Gynecology
“___”______________________ 200_ year
protocol #
T.a. The Head of the department
Professor
________________ O. Andriyets
METHODOLOGICAL INSTRUCTION
for practical lesson
“Abnormalities of conceptus’ development. Multifetal pregnancy. Malpresentations of
fetus.”
MODULE 2: Pathological flow of pregnancy, labor and puerperium
CONTEXT MODULE 3: Pathological flow of pregnancy, labor and puerperium
Subject: Obstetrics and Gynecology
4th year of studying
2nd medical faculty
Number of academic hours – 4
Methodological instruction developed by:
assistant Andriy Berbets
Chernivtsi – 2008
Aim: be able to diagnose of conceptus' abnormalities. To learn the peculiarities of pregnancy
duration in polyhydramnios, multifetal pregnancy, to diagnose the main complications in labor in
DOlyhydramnios, multifetal gestation.
Professional Motivation: forecasting the probability of an inherited disorders an important step.
But it requires a precise medical history and administration of appropriate genetic tests. In fact,
pregnancies with multiple fetuses pose significant medical risks for both the mother and her
offspring. Special care is necessary to achieve an optimal outcome. In general, all potential
complications with twin pregnancies are somewhat more frequent and more serious as the
number of fetuses increases.
Basic Level:
1. Chromosome's and gene's structure, their changes.
2. The main immunogenetical and immunodeficient syndromes.
3. Stages of ovum's development, sperm's structure and function.
4. Stages of trophoblast's and embryo' development.
5. Critical periods of intrauterine birth development.
6. Conceptus' structure.
7. Methods of examination in Obstetrics.
8. Uterine sizes in different terms of pregnancy.
9. Sizes of conceptus at the end of pregnancy.
10. Biophysical sizes of the fetus at the end of pregnancy.
11. Clinical duration of normal labor.
STUDENTS' INDEPENDENT STUDY PROGRAM
I. Objectives for Students, Independent Studies
You should prepare for the practical class using the existing textbooks and lectures. Special
attention should be paid to the following:
1. Principles of medical-genetic counseling organization.
2. Tasks of medical-genetic counseling.
3. Structure of the medical-genetic counseling.
4. The causes of the conceptus abnormalities occurring.
5. Patients which should be examinate in medical-genetic counseling,
6. Methods of medical-genetic counseling.
7. The essence of genetic method.
8. Determination of sex-chromatin.
9. Ultrasonography importance in prenatal diagnostics of fetal abnormalities.
10. Immunogenetical method of investigation.
11. Biochemical methods of investigation.
12. Clinical and laboratory characteristics of the diseases which have been occurred as a result
of chromosomal rearrangements and point mutations. .
13.The volume of the amnionic fluid at the end of pregnancy, fetal weight and height at interm
pregnancy.
14. Signs of multifetal pregnancy.
15. Peculiarities of pregnancy duration in multiple gestation.
16. Peculiarities of labor duration in multiple gestation.
17. Management of labor in multiple gestation.
18. Differential diagnosis of monochorionic and dichorionic twins.
19. Etiology of polyhydramnios.
20. Diagnosis of polyhydramnios.
21. Peculiarities of pregnancy duration polyhydramnios.
22. Peculiarities of labor duration and its management in polyhydramnios.
23. Which fetuses are called as "large" and "giant"?
24. Diagnosis of pregnancy in macrosomic fetus.
25. Etiology of fetal macrosomia.
26. Complications in labor with macrosomic fetus.
27. Peculiarities of labor management in macrosomic fetus.
Key words and phrases: medical-genetic counseling, fetal anomalies, pregnancy.
Polyhydramnios, multifetal pregnancy and macrosomic fetus.
Summary
Abnormalities of conceptus’ development
Impact on Obstetric Care. 1, More awareness of fetal structural or certain genetic conditions
either in gestation or before birth: a) options - abortion (if early in gestation) or continue
pregnancy and delivery at hospital capable of helping newborn; b) reassurance if normal
findings; c) overall risk of major anomalies at birth - 2-4 %. 2. Difficult or impossible to predict
behavior and cognitive development in infancy and childhood.
Counseling indications:
1. Environmental hazards: radiation - diagnostic, therapeutic; 2) drugs, chemicals - very few
associated with specific anomalies; need to know name of medication, dose, duration, gestational
age, accompanying medications and illness; less know in humans about pesticide and workplace
chemicals. Should avoid or at least allow minimal exposure in well-ventilated area; 3) infections
- viruses: cytomegaloviruses, rubella, parvovirus, hepatitis; mother is often asymptotic; fetal
risks - grow delay, anemia, stillbirth, intracranial calcifications, blindness, impaired hearing; may
linger or remain dormant; unable to eradicate; bacterial — gonorrhea, streptococcal, Klebssieila,
E;Coli; direct risk less than virus; less subtle since mother usually symptomatic; antibiotics may
eradicate before or after delivery; more of acute, nonlingering problem than viral infection.
2. Prior anomalous infant — cause is usually multifactorial, polygenic etiology; recurrence risk
of defect - midline facial cleft (2-4 %), cardiac (2-5 %), open neural tube(2-4 %), hydrocephaly
(1 %), pyloristenosis (3 %), renal agenesis (1-3 %); assess any underlying medical disorder
(diabetes, seizures) and medication.
3. Family history of mental retardation - common to find indirect family members; usually to
added risk; inquire about any chromosomal testing, inborn errors of metabolism, or
abnormalities during pregnancy in question
4. Advanced maternal age - routine for 35 and older at the time of delivery.
5. Abnormal serum alphafetoprotein (MSAFP). Prenatal Diagnostic tests:
1. Alpha fetoprotein (AFP) - a fetal-specific glycoprotein manufactured in yolk sac; highest
concentration in fetal serum but measurable in smaller amounts in maternal serum
(transplacental passage) and amniotic fluid (fetal urine); best measured in maternal serum
(MSAFP) between 15-20 weeks.
Indication - routinely offered, prior child with open neural tube defect, maternal diabetes, prior
or current pregnancy complications. Interpretation - elevated: open neural tube defect,
abdominal wail defect, erroneous dates, stillbirth, twins, abnormal placenta, nephrosis; low chromosomal (especially trisomy 21), erroneous dates.
2. Amniocentesis (14-18 weeks' gestation).
Test
Indication
Alpha fetoprotein
Elevated MSAFP; prior child with open
neural tube defect.
Chromosomes
Maternal a^e more than 35 years old;
Low MSAFH; Prior child with X-linked
disease; Prior child with chromosomal
disorder.
Inborn error of
Prior child with inborn error
metabolism
metabolism
3. Ultrasonography (twice during pregnancy - 16-18 and 25-26 weeks' gestation).
4. Chorionic villus sampling (8-12 weeks' gestation).Aspiration of placental tissue
transcervicall^/ or transabdorninally, increased risk of spontaneous abortion and contaminated
cells may lead to mosaicism.
5. Cordocentesis / percutaneous umbilical Hood sampling -transabdominal sampling of fetal
blood through umbilical cord vein.
6. Fetal skin sampling, fetal tissue biopsy, fetoscopy are used only fot the diagnosis of rare
disorders not amenable to diagnosis by less invasive methods.
Polyhydramnios and Multifetal pregnancy.
Polyhydramnios is excessive amnionic fluid. Normally, the volume of amntonic fluid increases
to about 1L -1,5 L more by 36 weeks but decreases thereafter. Somewhat, more than 2000 mL of
amniotic fluid is considered excessive, or hydramnios. In acute hydramnios, the volume
increases very suddenly and the uterus may become markedly distended within a few days. In
chronic hydramnios, the increase of amniotic fluid is gradual.
Etiology. Hydramnios is frequently associated with fetal malformations especially of the central
nervous system and gastrointestinal tract, its’ incidence is increased in pregnancies complicated
by diabetes and immune and nonimmune hydrops. Infective disorders can provoke hydramnios
aiso.
Diagnosis. Uterine enlargement in association with dufficulty in palpating fetal small parts and
in hearing heart tones. In severe cases, the uterine waif may be so tense that it is impossible to
palpate any part of the fetus. Sum findings call for prompt ultrasonic examination to better
quantify amnionic' fluid and to identify multiple fetuses or fetal abnormalities.
Treatment. Minor degree of hydramnios rarely require treatment. Iai| the case of infective
etiology of polyhydramnios - antibacterial treatment is recommended.
Management of labor. Early amniotomy is recommended to prevent uterine contractions
abnormalities. In the third stage of labor contractile drugs for prevention of early postpartum
hemorrhage are used.
Multiple pregnancy. Dizygotic twins occur when two separate ova are fertilized by two separate
sperms, and , in fact, represent two siblings who happen to be born at approximately the same
time. Monozygotic twins represent division of the fertilized ovum at various time after
conception.
Diagnosis. Twin pregnancy usually suspected when the uterine size is excessively large for the
calculated gestational age. The diagnosis is made by obstetric ultrasonography.
Pregnancy complications associated with multiple fetuses: abortion, perinatal death, low birth
weight, fetal malformations, pregnancy induced hypertension, maternal anemia, placental
accidence, uterine atony, cord accidents, uterine atony, hydramnios, abnormal fetal
presentations, complicated labor.
Fetal macrosomia. The definition of fetal macrosomia in the literature but the most commonly
cited definition is birth weight greater than 4000 g. Infants with weight more than 5000 g called
as "giant".
Macrosomic infants have a mortality rate two to five times greater controls. These infants have
an increased risk for shoulder dystocia, meconium aspiration, asphyxia, brachial plexus injury,
placenta previa, and fetopelvic disproportion. The macrosomic fetal head is larger than average,
and it is harder, with less potential for molding. Size of fetal trunk may also contribute to
dystocia and mechanical problems at delivery, labor abnormalities include a protractile phase
with a prolonged deceleration phase and protracted descent.
Risk factors for fetal macrosomia include multi parity, maternal obesity, heavy birth weight in
the mother or father, advanced maternal age, excessive weight gain during pregnancy, a previous
macrosomic infant, and prolonged gestation.
Prognosis. Since macrosomic infants are more common often born to multi parous mothers and
to women with diabetes, both the maternal and fetal risks are increased.
Malpresentations. Obstetric versions.
The transverse lie is the condition when the long axis of the fetus is approximately perpendicular
to that of the uterus. When it forms an acute angle, an oblique lie results. An oblique lie is
usually only transitory, however, for either a longitudinal or transverse lie commonly results
when labor supervenes. For this reason, the oblique lie is termed unstable lie.
An unstable lie is one in which the presenting part alters from week to week. It may be either a
transverse or oblique lie or possibly a breech presentation. These are relatively uncommon
events but are found in association with the following conditions:
1. Grand muitipara. This is by far the commonest factor, due to the lax uterine and abdominal
walls, which prevent the splinting effect found in women with lesser parity.
2. Poiyhydramnios. The volume of fluid distends the uterus and allows the fetus to swim like a
goldfish in a bowi — often taking up an oblique or transverse lie.
3. Prematurity. Here there is a relative excess of fluid to the fetus. If preterm labour occurs, the
fetus may be found to have a transverse lie.
4. Subseptate uterus. The septum prevents the fetus from turning in utero.
5. Pelvic tumors such as fibroids and ovarian cysts may not only prevent the lower pole from
engaging, but cause it to take up a transverse lie.
6. Placenta praevia. This usually prevents engagement of the presenting part. Because of this it
may present with the fetus in an oblique or transverse lie.
7. Multiple pregnancies may present with a transverse lie. If this occur, it is more common in the
second twin.
Diagnosis of the transverse and oblique lies: 1- The external inspection shows than the
abdomen is unusually wide from side to side, whereas the fundus of the uterus extends scarcely
above the umbilicus. On palpation, with the first maneuver no fetal pole is detected. On the
second maneuver, a ballottable head is found in one side and the breech in other. The third and
fourth maneuvers are negative unless labor is vvoii advanced and the shoulder has become
impacted in the pelvis. When the fetal head is situated in the left side of the uterus th first
position of the fetus is identified. When the fetal head is situated h the right side of the uterus the
second position is recognized. On vaginal examination, in the early stages of labor, the side of
the thorax, if it can be reached, may be recognized above the pelvic inlet. When the dilatation is
further advanced, the scapula and the clavicle are distinguished on opposite sides of the thorax.
Later in the labor, the shoulder becomes tightly wedged in the pelvic canal, and a hand and arm
frequently prolapse into the vagina and through the vulva.
Management of transverse and oblique lie. It is not uncommon for the fetus to have a
transverse lie until about the 32nd week of pregnancy If the transverse lie persists after this time
a cause should be determined. An ultrasound examination should be done to exclude placenta
praevia, ovarian tumor or fibroid and if either of these conditions are present an elective cesarean
section should be performed at 38-39 weeks of gestation. The ultrasound is also used for
identifying twins and a subseptate uterus, whilst a vaginal examination will confirm a pelvic
tumor.
The main risk of a transverse or oblique lie is in association with preterrn rupture of the
membranes and cord prolapse. When diagnosed the state of the cervix should be checked. If the
cervix is dilated, the patient should be admitted to hospital. If, however, the cervix is closed and
the membranes are intact the patient may be reviewed on a regular basis. If no easily identifiable
cause is found, attempted external cephalic version can be made after 34 weeks. In grand
multipara patients,the fetus will usually turn easily but will often swing back to an abnormal lie.
If the abnormal lie persists or constantly reoccurs, the woman should be admitted to hospital by
the 38th week. If external version is successful at this stage and the patient's cervix is favorable
then artificial rupture of the membrane can be performed with the head held over the pelvic brim
and an oxytocin drip commenced to augment uterine activity. If the cephalic presentation is
maintained, labor may be allowed to continue. If the transverse or oblique lie reoccurs in labor
then a cesarean section must be performed.
Complications of a transverse lie. If a mother goes into labor with a transverse or oblique
lie,several catastrophes may occur. Because this occurs more commonly in multiparous women
and their uterine activity is often much stronger, rupture of the uterus is more likely. When the
membranes rupture there is a greatly increased danger of cord prolapseObstetrics versions
Operations for correction of abnormal lie or presentation of fetus as obstetrics versions. There
are two types of obstetrics versions: external and internal podalic version. Indications for
obstetrics versions: fetal malpresentations (breech, transverse and oblique lie).
Contraindications. Complicated pregnancy, multifetal pregnancy, ngenital uterine anomalies,
placenta previa, feto-pelvic disproportion.
Conditions: for the external version - 32-36 weeks, intact membranes, normal movement of the
fetus in the uterus, satisfactory fetal and mother condition; for the internal podalic version cervix must be fully dilated, intact or just rupture membranes, normal movement of the fetus in
the uterus, satisfactory mother condition, absence of fetopelvic disproportion.
The internal podalic version consists of such moments:
1. Inserting a hand into uterine cavity.
2. Finding a foot.
3. Grasping one foot.
4. Drawing foot through the cervix while exerting pressure transabdominally in the opposite
direction on the upper portion of the body.
The version is finished when fossa poplitea of the grasping foot in presented in the pudendal
cleft.
II. Tests and Assignments for Self-assessment.
Abnormalities of conceptus’ development
Multiple Choice.
Choose the correct answer / statement:
1. An abnormally low serum alphafetoprotein (MSAFP) result is associated with:
A - Twins; B - Stillbirth; C — Trisomy 21; D - Abdominal wall defect; E - Open neural tube
defect.
2. Which statement is true about drug effects on the fetus?
A - Facial clefts should be excluded;
B - Many are associated with special anomalies;
C - The risk of major anomalies is 2-4 %, regardless of any drugs;
D - An amniocentesis for karyotyping is helpful;
E - Teratogenic risk is synonymous with minor and major birth defects.
3. An indication for an advanced or targeted ultrasound scan would be:
A - Rule out the twins;
B - Localize the placenta;
C - Confirm a breech presentation;
D - Evaluate polyhydramnios;
E - Guide the needle during amniocentesis.
Real -life situations to be solved:
4. A 24-year-old woman presents with a history of 10 weeks amenorrhea, Clinical examination
reveals signs of pregnancy. During ultrasonography fetal anomaly was marked - absence of the
fetal head. What would be the most probable diagnosis? What should be administrated?
5. A 24-year-old, accompanied by her 27-year-old husband, presents with a history of 8 weeks of
amenorrhea and the onset, earlier in the day, f cramping and bleeding. Clinical examination
reveals an incomplete abortion and a suction and curettage is performed without incident. At the
parents' request,the tissue is sent for genetic evaluation. She is Rh+ and in good health. Each has
a negative family history of congenital anomalies and inherited disease and negative personal
medical histories. Her physical examination is normal. On her first office visit one week after the
miscarriage, her physical examination is normal, and she feels well, although depressed. The
couple questions what the significance of the miscarriage will be for future pregnancies. Your
answer will include which of the following?
A - The likelihood of the next or subsequent pregnancies carrying to term is less than 35 %;
B - The likelihood of this pregnancy demonstrating a genetic disorder is less than 5 %;
C - The likelihood of their being able to conceive is reduced by 67 % compared with couples
who have had no miscarriage;
D - All of the above;
E - None of the above.
6. Three weeks later a genetic report is received indicating trisomy 16. You inform the patient
and her husband of this information and suggest:
A - They consider adoption;
B - They consider sterilization of one or both partners and adoption;
C - They continue with their plans to have another pregnancy in approximately 6 moth;
D - All of the above;
E - None of the above.
Answers to the Self- Assessment
1.C. 2.C, 3. D. 4, Ten weeks of the first pregnancy. Fetal anomaly -anencephaly. Interruption of
the pregnancy on medical indications should be administrated. 5. E. Absent identified risk
factors, the chances of conceiving and carrying the next pregnancy to term are not reduced.
Provided the tissue obtained at suction and curettage is viable enough to permit culturing, the
chances of a genetic anomaly are approximately 50 %. 6. C. Trisomy 16 is associated with lethal
outcomes in the first trimester. Your previous advice about future pregnancy remains valid.
Polyhydroamnios. Multifetal pregnancy.
Multiple Choice.
Choose the correct answer / statement:
1. Which infant is called to be giant?
A - Birth weight greater than 4000 g;
B - Birth weight greater than 3500 g;
C - Birth weight greater than 5000 g;
D - Birth weight greater than 3600 g;
E - Birth weight greater than 3900 g.
2. Which of the following should be included in the differential diagnosis when uterine size is
excessively large compared with the calculated gestational age?
A - Twins; B - Polyhydramnios; C - Uterine fibroids; D - Hydatidiform mole; E - All of the
above.
3- All of the following are more commonly associated with multiple pregnancy EXCEPT:
A - Megaloblastic anemia; B - Fetal macrosomia; C - Vasa previa;
D - Congenital anomaly; E - Polyhydramnios.
4. A twin pregnancy in which one twin is characterized by impaired growth, anemia, and
hypovolemia and the other twin by hypervolemia hypertension, poiycythemia, and congestive
heart failure is suffering form:
A - Conjoined twin syndrome;
B - Twin- twin syndrome;
C - Single umbilical artery syndrome;
D - Congenital rubella syndrome;
E - Isoimminization.
Real - life situations to be solved:
5. At 32 weeks of pregnancy, a 35-year-old woman with known twins is noted to have a fundai
height not commensurate with gestational age. Her weight gain and blood pressure are normal as
are her antenatal? laboratory studies. She says the babies are moving normally and that she feels
well, although "rather large". Which of the following interventions, if any, are indicated?
A - Oxytocin challenge test;
B - Ultrasound;
C - Induction of labor if cephalic/cephalic presentation;
D - Cesarean birth.
6. At ultrasound her twins are noted to be monochorionic/diamniotic, with both twins moving
actively in adequate amounts of amniotic fluid. Comparison of twin A to twin B shows 25 %
difference in weights, with twin B being the larger. An NST is reactive for both twins so that
their biophysical profile is 10/10 for each twin. What would be your bests recommendations?
Answers to the Self-Assessment.
1. C. 2. E. 3. B.4. B. 5. B. Intrauterine growth restriction and discordant growth are both
common in twin pregnancies. Measurement of each fetus’; for comparison may reveal abnormal
development. 6. Biweekly NSTs and' weekly biophysical profiles and evaluation for fetal
growth.
Students must know:
1. The main peculiarities and functions of genes.
2. Chromosome's structure, their changes.
3. The main immunogenetical and immunodeficient syndromes, birth defects and their prenatal
diagnostics.
4. Signs of multiple gestation.
5. Peculiarities of pregnancy duration in multiple gestation.
6. Management of labor in multiple gestation.
7. Differential diagnosis of monochorionic and dichorionic twins.
8 Diagnosis of polyhydramnios.
9. Peculiarities of pregnancy and labor duration in polyhydramnios.
10. Which fetuses are called as "large" and "giant"?
11. Diagnosis of pregnancy with rnacrosomic fetus.
12. Complications in labor with rnacrosomic fetus.
13. Management of labor with macrosomic fetus.
Students should be able:
1. Determine of the high risk pregnant in the development of inherited diseases of the infant and
birth defects, administrate of necessary investigations for them
2. Perform of ultrasonograpxhy of pregnant and to assess revealed dates.
3. To diagnose polyhydramnios, to prescribe treatment and to make a plan of labor in
polyhydraamnios.
4. To differentiate monochorionic and dichorionic twins.
5. To diagnose multifetal pregnancy, to make a plan of labor.
6. To determine the probable fetal weight and to diagnose "large" fetus.
7. To make a plan of labor in "large" fetus.
Malpresentations. Obstetric versions.
Multiple Choice.
Choose the correct answer / statement:
1. Which is the most appropriate treatment for the woman on 34 week of gestation having an
oblique lie of the fetus? A - The classic version of the fetus; B - To stimulate delivery: C —
Cesarean delivery; D - External version of the fetus.
2. A 17-year-old patient at 39 weeks gestation presents to the hospital with transverse lie of the
fetus. Which is the most appropriate treatment?
A - External version of the fetus;
B - Rupture of the fetal membranes to stimulate delivery;
C - Immediate cesarean delivery;
D - An immediate vaginal delivery.
3. What are the requirements for internal podalic version of the fetus?
A - Normal temperature of the body
B - Cervix must be fully dilated;
C - Membranes must be ruptured;
D - All of the above.
Real — life situations to be solved:
4. A multipara at 38 weeks of gestation entered the obstetrical department with normal labor
activity. Complaints of the cough, headache The temperature of the body is 38,7 °C. Pelvic sizes:
25-28-31-20. Expected weight of fetus is 3000 g. Fetal heart tones are normal. The presenting
part is not palpated upon the pelvic inlet. The head is situated in the left part of the uterus.
Vaginal examination shows: the cervix is completely dilated. The membranes are intact.
Shoulder of the fetus is palpated as a presenting part. Which is the most appropriate treatment?
III. Answers to the Self- Assessment.
1. D. 2. C. 3. D. 4. Labor, at term, second stage. Acute respiratory disease. Transverse fetal lie.
The most appropriate management is internal podalic version.
References:
1. Danforth's Obstetrics and gynaecology. - Seventh edition.- 1994. - P. 201-225.
2. Basic Gynecology and Obstetrics. - Norman F. Gant, F. Gary Cunningham. -1993. -- P. 406412.
3. Obstetrics and gynecology. - Pamela S.Miles, William F.Rayburn, J.Christopher Carey. Springer-Verlag New York, 1994. - P. 62-64.