Download Abnormalities of conceptus` development. Multifetal pregnancy

MINISTRY OF PUBLIC HEALTH OF UKRAINE
NATIONAL PIROGOV MEMORIAL MEDICAL UNIVERSITY, VINNYTSYA
CHAIR OF OBSTETRICS AND GYNECOLOGY №1
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
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. 406-412.
3. Obstetrics and gynecology. - Pamela S.Miles, William F.Rayburn, J.Christopher
Carey. - Springer-Verlag New York, 1994. - P. 62-64.