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Multiple Pregnancy Definition: The development of more than one fetus in utero at the same time. Two fetus: Twins three fetus: Triplets Four fetus: Quadruplets Five fetus: Quintuplets Six Fetus: Sextuplets etc. 1

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Multiple Pregnancy

Definition: The development of more than one fetus in utero at the same time.

• Two fetus: Twins

• three fetus: Triplets

• Four fetus: Quadruplets

• Five fetus: Quintuplets

• Six Fetus: Sextuplets etc.

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Multiple Pregnancy Cont...

Twin pregnancy: Development of two fetus in utero at the same time.

Types of Twin Pregnancy:

1. Monozygotic/Uniovular/Monovular/ Identical/

2. Dizygotic/Binovular/Fraternal/

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Multiple Pregnancy Cont...

A. Monozygotic Twins:

• Develop from one ovum and one spermatozoon which after fertilization split in to two.

• Are always of the same sex

• Have the same gene, blood group, and physical features eye and hair color, ear shapes and ear creases)

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Multiple Pregnancy Cont...

• Most of the time are of d/t size

• Placenta: one or two

• Chorion: one or two

• Amnion: one or two

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Multiple Pregnancy Cont...

B. Dizaygotic Twins:

• Develop from two separate ova that fertilizes by different spermatozoa.

• May be of the same sex or not

• Placenta two but may be fused

• Two chorions

• Two amnions

• Tend to run in families

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Multiple Pregnancy Cont...

Diagnosis: Multiple gestations should be suspected whenever 1. the uterus seems to be larger than dates,2. auscultation of more than one fetal heart is suspected, 3. the pregnancy has occurred following assisted

conception, or 4. family history. 5. Multiple gestations may also be diagnosed

serendipitously at the time of ultrasound scanning, such as before a genetic amniocentesis or as a result of an elevated serum alpha-fetoprotein (AFP) level in mass-screening programs.

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Multiple Pregnancy Cont...

Super fecundation: is the term used when twins are conceived from sperm from d/t men if a woman has had more than one partner during a menstrual cycle.

Super fetation: is the term used when twins conceived as a result of two coital acts in d/t menstrual cycle.

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Multiple Pregnancy Cont...

Determination of Zygosity and Chorionicity

• Determination of zygotsity means deterring whether or not twins are monozygotic or dizygotic

• At birth monochorinic twins tend to have great Wt variation than dichorionic ones.

• In approximately 2/3rds of monozygotic twins, a monochorionic diamintioc placenta (MCDA) will confirm monozygosity.

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Multiple Pregnancy Cont...

• If the babies have single outer membranes, the chorion, they must be monochorionic so monozygotic.

• In one third of monozygotic twins, the placenta will have two chorions and two amnions (DCDA) and either fused placenta or separate placenta (Dichorionic), which in indistinguishable from situation in dizygotic twins.

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Multiple Pregnancy Cont...

• With monozygotic twins the type of placenta produced is determined by the time at which the fertilized oocyte splits;

– 0-4 days –DCDA(1/3rd )

– 4-8days –MCMA(2/3rd )

– 8-12days –MCMA (1%)

– 12-13days –(very rare) conjoined twins when the division is incomplete.

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Multiple Pregnancy Cont...

Chorionicity: why is it important to know?

Because: Monochorionic twins pregnancies have 3-5 time high-risk of perinatal mortality and morbidity than Dichorionic ones.

• Determined by U/S preferable during 1st

TMS(difference more pronounced during this stage)

• The chorion forms a septum b/n the amniotic sac.

• If the septum has a mean thickness of 2-3mm or more Dichorionic

• If <1.4mm monochorionic.

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Multiple Pregnancy Cont...

• By studying the septum at its base adjust to the placenta

• Twin peak

• Lambda sing Dichorionic Tongue of placenta tissue b/n the two chorion by u/s

Zygosity Determination after Birth

• DNA- the most accurate (cells taken for cheek swab inside the mouth)

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Multiple Pregnancy Cont...

Diagnosis of twin pregnancy • History: Family history of twin pregnancy• Abdominal examination: Inspection: • Size of the uterus is larger than expected• The uterus looks like broad or round• Fetal movement may be seen over wide area • Fresh straigravidarm • Up to 2x normal amniotic fluid volume is normal.

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Multiple Pregnancy Cont...

Palpation: • FH is greater than expected • Presence of two fetal poles (head or breach) in

the fundus may be revealed • Multiple fetal limbs may also be palpable• The head may be small in relation to the size of

uterus• Two fetal backs on lateral palpation• Location of three poles in total is diagnostic of at

least two fetuses

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Multiple Pregnancy Cont...

Auscultation:

• Hearing two FHB is not a diagnostic

• Simultaneous comparison of FHB reveals a d/t of at least 10BPM may be assumed that two hearts are being heard.

Ultrasound:

• As early as 6 weeks of pregnancy

• Vanishing fetus syndrome( fetus papyraceons) may happen.

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Multiple Pregnancy Cont...

The pregnancy

• A multiple pregnancy tends to be shorter then singleton pregnancy

• Average gestation for twins

– 37wk-twins

– 34wk-triple

– 33wk-quaderplet

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Multiple Pregnancy Cont...

Management of Twin Pregnancy

Ante partum:

• Nutrition:

• Consumption of energy sources should be increased by 300kcal/day above that of singleton pregnancy

• Supplementation of iron and folic acid– Iron 60 to 100mg/d

– Folic acid 1mg/d

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Multiple Pregnancy Cont...

Frequent prenatal visit

Rest

• Limited physical activities

• Early work leave

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Multiple Pregnancy Cont...

Ultrasound evaluation of:

• Placentation (aminonicity and Chorionicity)

• Number of fetus

• Fetal amniotic fluid

• Placental abnormality

• The growth of each fetus

• The presentation of congenital anomaly (ies)

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Multiple Pregnancy Cont...

Ante partum surveillance• Indicated in complicated multifetal gestation Technique:• Modified biophysical profile• Fetal movement counting ( count to ten chart)Preterm labour • Tocolytic gents; for short term prolongation of

pregnancy • Corticosteroid administration: before 34 wk of

gestation

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Multiple Pregnancy Cont...

PROM • Manage like singleton pregnanciesCorticosteroids: • For women having impending delivery and GA

less than 34 wk Betamethasone. 12mg doses 24 hrs apart.

VBAC :Contraindicated Timing of delivery: • All should undergo delivery by 40 wks of

gestation

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Multiple Pregnancy Cont...

Intra partum:

• All preparations should have been made for resuscitation and special care of babies of LBW

• Labour and delivery

• Ascertain fetal number , presentation, EFW and placental location

• Blood transfusion products should be readily available

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Multiple Pregnancy Cont...

• Close monitoring of FHB in both twin

• Analgesia /anesthesia

– Use minimal analgesia for labour

• Epidural

• Pudendal block

• General anesthesia for C/S

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Cont…

• Following the delivery of 1st twin:

– Cut the cord as far outside the vagina as possible clamped

– Perform Leopold’s maneuver for the lie and virginal examination to note:

– Presentation of the 2nd twin

– The presence of a second sac an occult cord prolapse or cord entanglement

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Multiple Pregnancy Cont...

If the vertex/ breech is in or over the inlet and the uterus is contracting –ARM should be done on the second sac.

If uterine inertia has set in – start on oxytocin drip with anatomy

When either twin shows signs of persistent compromise proceed promptly to c/s delivery.

interval b/n deliveries 15-30minutes

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Rout of delivery:• Twin A-vertex/twin B vertex delivery vaginal. c/s

should only be performed for the same indications applied to sningltoun gestation

• Twin A-vertex /Twin B Non vertex Twin A-vaginal Twin B; vaginal for neonate with an EFW greater than

1500gms option:• ECV• Total breech extraction • Assisted breech delivery • Internal podalic version • c/s for twin B whose birth weight is less than 1500gms

Twin A- non vertex – C/S

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Multiple Pregnancy Cont...

Routine cesarean delivery:

• Conjoined twin

• Placenta previa

• Mono amniotic twin

• Possible inter locking twin

Placentas:

• Delivery after both twins have been born

• Check for Chorionicity, amnionicity, number of placenta and vascular communication

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Multiple Pregnancy Cont...

Zygosity:

• Examine the dividing membrane

Monozygotic: commonly have an opaque (thin) septum made up of 2 amniotic membranes only (no chorion and no decidua)

Dizygotic: always have an opaque (thick) septum made up of 2 chorions 2 amnions, and intervening decidua

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Multiple Pregnancy Cont...

Third stage of labour:

• Active management

Induction and augmentation

• Not recommended

Delayed (deferred) delivery of the second twin

• Candidates: patients at more than 28 wks of gestation

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Multiple Pregnancy Cont...

Management:

• umbilical cord of the 1st twin legated high at the cervix

• Prophylactic antibiotics

• Bed rest

Contraindications to Deferred delivery of the 2nd twin

• Aminionitis

• Evidence of fetal compromise

• Heavy vaginal bleeding

• Monochoricity

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Multiple Pregnancy Cont...

Complications

1. Discordant twins:

• Definition: A difference in EFW of greater than 20% b/n twin A and twin B expressed as percentage of the larger twins weight.

• Antepartum Evaluation:– Serial ultrasound every 4 wks

– Biophysical profile starting from 28wks

– Termination of pregnancy when the BPS is poor

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Multiple Pregnancy Cont...

2. Twin to twin transfusion syndrome (TTTS)

Diagnosis one or more of the following:

• Placenta vascular connection

• Hgb differences greater than 5g/dl

• Inter twin birth weight d/t greater than 20%

• Hydramnoius in the large twin Oligohydramnious in growth restricted fetus

• Monochorionicity and same sex.

Therapy: serial aminocentesis for hydraminus

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Multiple Pregnancy Cont...

3. Death of one fetus:

• Management – expectant

– Clotting profile every week

– Fetal surveillance

• No intervention aimed at arresting the labour when the diagnosis is made during active labour

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Multiple Pregnancy Cont...

4. Conjoined twin:

Suspicion provoking factor

• Finding of single fetal heart in multiple pregnancy

• Lack of engagement when the lie is longitudinal

• A similar parallel lie (vertex-vertex, breech-breech)

• An abnormal fetal attitude

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Multiple Pregnancy Cont...

Method of diagnosis • Ultrasound • Plan film of the abdomen • AmniographyMode of delivery: 1. C/S (lower segment vertical incision)2. vaginal

– Babies are small– Point and type of union permit mobility– Infant dead

3. Destructive operation: – When infant dead and part of the fetus has been born

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Multiple Pregnancy Cont...

5. Locking of twins:• One may impede the descent of the other Management: a. Collision, impaction, compaction:• Avoid strong traction and fundal pressure• Push the second twin out of the pelvis under

deep anesthesia• Then delivery the first and second twin in the

usual way • If the method fails and babies are alive do C/S

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Multiple Pregnancy Cont...

b. Chin to chin interlocking:

• Avoid traction of the first twin

• Unlock the chin under anesthesia and the second win is pushed out of the way

• If the first baby dies break the locking by decapitating the first twin delivery of the second baby and delivery of the head of the first baby by traction

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Multiple Pregnancy Cont...

6. Triplets or other higher order pregnanciesMust be considered:• Whenever multi-fetal gestation is suspected• In all pregnancies resulting from ovulations

induced by gonadotropins or clomipheneDiagnosis:• Ultrasonography• X-ray during the late 2nd and 3rd trimester Management: • Similar to twins

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Multiple Pregnancy Cont...

Mode of delivery:

• Cesarean section; virtually for all high ordered multiple gestation

• Vaginal delivery: for those fetuses who are markedly immature or complications that make cesarean delivery hazardous to the mother.

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Multiple Pregnancy Cont...

Complications cont…

• Malpresentaion

• Cord prolapse

• Prolonged and obstructed labour

• Undiagnosed twins

• Fetus in fetu(part of a fetus may be locked within another fetus)

• PPH

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Problems associated with pregnancy following assisted

conception

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• Couples who achieve pregnancy following assisted conception may be at greater risk of complication during pregnancy than those who conceive naturally b/s:

• The cause of the infertility may be medical problem

• There is an increased risk of multiple pregnancy which in form increase the risks pre term labour, pre eclampsia and so on

• Usually in older age group increased age is associated with pre eclampsia, multiple pregnancy, medical problem like DM, uterine fibroids etc.

• Therefore they need special attention 42

Quiz

1) What is zygosity? How can it determined in intrauterine life?

2) What is the difference between acute and chronic polyhydramious?

3) Write the physical appearance of post term baby

FOR YOUR PATIENCY

RH ISOIMMUNIZATION

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Introduction

The D antigen, also called the Rh factor is the most powerful and important of the Rh antigens. An individual who possess it is labeled as Rh positiveand who lack it as Rh negative.

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• Exposure of these Rh-negative people to even small amounts of Rh-positive cells, by either transfusion or pregnancy, can result in the production of anti-D antibody, a condition called Rh sensitization or isoimmunization.

Definitions

Rh incompatibility is the presence of different Rh types in a woman and her partner. In obstetrics, the significant incompatibility is when the woman is Rh negative and the partner is Rh positive

Rh isoimmunization (Rh sensitization) is production of antibody against the Rh factor by an Rh negative woman following exposure to Rh-positive cells

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• The first encounter may not result in actual antibody formation

• but the woman will be sensetised; on asecondencounter, antibodies are produced in abundance. Once formed, these antibodies are permanent.

Erythroblastosis fetalis is the condition in which large numbers of nucleated red cells are seen in the fetal circulation, occurring in response to excessive destruction of fetal red blood cells

Hydrops fetalis is generalized edema in the fetus and collection of serous fluid in body cavities of the fetus resulting from a variety of pathologic conditions (immune hydrops and non immune hydrops).

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Hemolytic disease of the newborn is occurrence of progressive anemia and hyperbilirubinemia in a newborn caused by haemolysis of red blood cells, in most cases antibody mediated

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Pathogenesis

For Rh isoimmunization to occur, the following prerequisites must be fulfilled:

I. Rh negative mother carrying Rh positive fetus

The chance of having Rh positive fetus from Rh positive father ranges from 50% (if the father is heterozygous) to 100% (if the father is homozygous).

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II. Entry of the fetal Rh positive red blood cells into maternal circulation

This occurs following transfusion of incompatible blood (rare now a days because of screening before transfusion) or more commonly following fetomaternal hemorrhage (through leaks in the placenta)

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• Conditions that aggravate fetomaternal hemorrhage are

spontaneous or induced abortion,

ectopic gestation,

antepartum hemorrhage especially abruptio placenta,

amniocentesis, abdominal trauma, and external cephalic version

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III. Development of Rh antibodies by the mother

• The maternal immune system responds by producing antibodies which are initially of IgMtype (big immunoglobulin that can not pass the placental barrier). Fetomaternal bleeding in the subsequent pregnancies results in the an amenstic reaction producing an IgG type of antibody (small antibody that can pass the placental barrier)

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Cont…

Effects on the fetus and the newborn

Hemolytic anemia develops, the extent of which depends on the amount of antibody. To compensate for the ensuing anemia the fetal bone marrow and later the extramedullary sites that produce RBC (liver, spleen and placenta) are called to produce red blood cells at fast rate. This results in the appearance of young nucleated cells in the blood stream.

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Cont…

• In severe cases even extramedullary hematopoiesis can not cope with the degree of destruction.

• This results in progressive anemia which eventually leads to congestive heart failure and tissue hypoxia.

• This condition is one of congestive heart failure due to gross haemolytic anaemia.

• At birth the baby is extremely pale, has sever edema and ascites and may be stillborn.

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• The liver parenchyma is replaced by hematopoietic tissue. Serum albumin falls as the result. The combination of these causes generalized edema of the fetus called hydrops fetalis. Eventually fetal death occurs.

Cont…

• Before delivery the bilirubin, mainly of unconjugated type is cleared by the placenta. Following the delivery of the fetus, increasing amounts of unconjugated bilirubin accumulate in the neonatal circulation (because the limited capacity of the liver to clear).

• The unconjugated bilirubin crosses the blood brain barrier and damages the basal ganglia to cause kernicterus.

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Prevention of maternal iso-immunisation

There are three ways of preventing a woman from producing Rhesus antibodies:

1) - avoiding transfusion of Rh positive blood

2)- prevention of avoidable fetomaternaltransfusion

3)- administration of anti- D immunoglobulin

Cont…Management of Rh negative un sensitized

pregnancy

I. Identification of pregnancies at risk at the initial ANC visit

Determine blood group & Rh factor and indirect coombs test for antibody screening for all pregnant mothers.

II. Management of unsensitized pregnancy

Determine the blood group and Rh factor of the partner

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Assignment

• What is coomb’s test

– Direct

– Indirect

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Cont…

Repeat indirect coombs test at 28 weeks and at 36 weeks. If negative consider antepartum prophylaxis with 300 micrograms of anti D gamma globulin at 28 weeks. If positive manage as sensitized pregnancy.

Provide anti D prophylaxis in cases with amniocentesis, APH, external cephalic version.

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Cont…Management of sensitized mother

These women need specialized care with measurement of antibody levels in titers at regular intervals, amniocentesis for bilirubin levels, serial ultrasound for detection of hydrops and management of neonatal anemia and hyperbilirubinemia.

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Cont…

Important points about ABO hemolytic disease

It occurs when the mother has group O blood (with anti-A and anti-B antibodies in her serum) and fetus is group A, B or AB.

Unlike Rh isoimmunization, 40-50% of ABO incompatibilities occur in the first-born infant.

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Cont…

ABO hemolytic disease is primarily manifest following birth, when the infant becomes jaundiced within the first 24 hours with a variable amount of anemia and hyperbilirubinemia which is usually mild. Serious complications almost never occur.

The management consists of measurement of bilirubin serially and provision of phototherapy to the newborn.