ASSOCIATE PROFESSORBlidaru Iolanda-Elena, MD, PhD.

♣ a high-risk pregnancy early and excessive distension of the uterus inappropriate uterine contractility

sharing the intracavitary space and placental nutrition IUGR

abnormal fetal presentation placenta praevia velamentous insertion of the cord

prematurity, HTA, caesarian section

IncidenceIncidence multiple gestations → 12% of total multiple gestations → 12% of total

conceptionsconceptions

14% of these survive to term14% of these survive to term

THE “VANISHING TWIN” THE “VANISHING TWIN”

- before the 2-nd trimester (20-60%)- before the 2-nd trimester (20-60%)

no evidenceno evidence

no riskno risk

Clasification

Monozygotic = identical twinsMonozygotic = identical twins

- a single fertilized ovuma single fertilized ovum

Dizygotic = fraternal twinsDizygotic = fraternal twins - two separate ovatwo separate ova

- variable rate - variable rate -- 1.3 (Japan) - 49.0 1.3 (Japan) - 49.0 (Nigeria)(Nigeria)// 1000 1000 birthsbirths

- Recessive autosomal trait (female line)- Recessive autosomal trait (female line)

Frequency of twinsFrequency of twins

a-a- Monozygotic Monozygotic: 1:250 (independent) : 1:250 (independent)

b-b- Dizyg Dizygootictic: 1:90 : 1:90 caucasianscaucasians USA USA

1:20 Africans1:20 Africans

Depend on race, heredity, age of mother, Depend on race, heredity, age of mother, parityparity,, fertility drugs, post-OC use moment. fertility drugs, post-OC use moment.

Etiology – FSH LEVELS1.1. Race - high in blacksRace - high in blacks,, less in Asians less in Asians

2.2. Heredity - mother Heredity - mother more more important important than fatherthan father

3.3. Age - peak incidence Age - peak incidence →→ 30-40 y30-40 yearsears

4.4. ParityParity

5.5. Drugs -Drugs - inductinductorsors of ovulation of ovulation

6.6. Assisted Reproductive Techniques Assisted Reproductive Techniques (ART)(ART)

7.7. Season - frequent in summerSeason - frequent in summer

DIVISION First 72 First 72 hourshours two embryos, two embryos, diamniotic, diamniotic,

dichorionic. dichorionic.

4-8 days 4-8 days two embryos, two embryos, diamniotic, diamniotic,

monochorionicmonochorionic. .

About 8 - 14 days About 8 - 14 days two embryos two embryos, ,

monoamniotic, monochorionic.monoamniotic, monochorionic.

After 14 days After 14 days cleavage is incomplete, cleavage is incomplete,

conjoined twinsconjoined twins..

Determination of ZYGOSITY and CHORIONICITY

US evaluation of chorionicity “twin peak” sign, ”T” sign fetal gender placental examination

Dichorionic diamnioticDichorionic diamniotic

dizygotic or monozygoticdizygotic or monozygotic

Monochorionic diamnioticMonochorionic diamniotic

monozygoticmonozygotic

Monochorionic monoamnioticMonochorionic monoamniotic

monozygoticmonozygotic

Monozygotic 30% single egg; an unique placenta,

with vascular anastomoses;

unique or double amniotic sacs;

phenotypic and genotypic identity;

twin-twin transfusion syndrome (TTTS);

hydramnios;

malformations.

Dizygotic 70% eggs distinctly

separated (dichorionic-diamniotic);

absence of vascular anastomoses;

normal volume of amniotic fluid;

fetuses without phenotypic or genotypic identity;

same or different sex.

Conjoined twins or Siamese twins

Vascular anastomoses between fetuses♣♣ only in only in monochorionicmonochorionic twins ( twins (≈≈100%).100%).

♣ ♣ 3 variants of vascular relationships: 3 variants of vascular relationships: hemodynamic balancehemodynamic balance;; marked asymmetrymarked asymmetry (15 to 30%); the perfused fetus (15 to 30%); the perfused fetus

presents hypervolemia, heart failure, acute presents hypervolemia, heart failure, acute

polyhydramnios, hyperbilirubinemia, polyhydramnios, hyperbilirubinemia,

hepatosplenomegaly; the hypo-perfused fetus has hepatosplenomegaly; the hypo-perfused fetus has

hypoxemia and oligohydramnios hypoxemia and oligohydramnios (twin-twin transfusion (twin-twin transfusion

syndrome);syndrome); slight asymmetryslight asymmetry - slow transfusion (the tranfused - slow transfusion (the tranfused

fetus has higher weight and mild polycytemia. fetus has higher weight and mild polycytemia.

TWIN TO TWIN TRANSFUSION SYNDROME (TTTS)Due to the common placental circulation and the anastomosis of the 2 fetal circulations

FETUS PAPYRACEOUSOne will regress in size, with oligohydramnios in its sac (if 2 sacs), may perish; then becomes dehydrated and mummified.

PLACENTAL ANASTOMOSES

FETUS PAPYRACEOUS IN TRANSFUSION SYNDROME

TWIN TO TWIN TRANSFUSION SYNDROME

CLINICAL DIAGNOSIS

1. History.

2. Clinical Examination.

3. Investigations.

HISTORY Family history (maternal side)Family history (maternal side) History of ovulation inductionHistory of ovulation induction High parityHigh parity Advanced maternal ageAdvanced maternal age Greater weight gain than expectedGreater weight gain than expected Abdominal size >duration of amenorrheaAbdominal size >duration of amenorrhea Pressure symptoms (dyspnea, dyspepsia)Pressure symptoms (dyspnea, dyspepsia) Marked edema of lower limb.Marked edema of lower limb.

CLINICAL EXAMINATION●●Uterine size - larger than expected for Uterine size - larger than expected for GAGA

++55cm (II trim.)cm (II trim.)

●●Palor, early edema, varicose veinsPalor, early edema, varicose veins●●Glossy skin, striae, evident colateral Glossy skin, striae, evident colateral

circulation.circulation. ●●Uterine palpation → two fetal heads or Uterine palpation → two fetal heads or

multiple multiple similar similar fetal parts.fetal parts.

●●Auscultation of FHS: Auscultation of FHS: 22 different sites and different sites and different frequencydifferent frequency

CLINICAL EXAMINATIONBimanual examination a fetal pole, smaller than

expected (related to uterine size)

sometimes, in hypogastrum the fetal poles can't be detected

uterine cervix may be effaced the membranes are under

tension.

Ultrasound examination → the number of fetuses → type of placentation → fetal size and possible anomalies → presentation, position and relation to each

other → fetal well-being and growth pattern for each → guidance to perform some maneuvers:

amniocentesis, villous sampling

INVESTIGATIONS

Biochemical testsBiochemical tests1.1. hCG in plasma and in urinehCG in plasma and in urine2.2. AFP level (alone is not diagnostic)AFP level (alone is not diagnostic)3.3. estriol estriol 4.4. HPLHPL

Differential diagnosis1. Hydramnios.2. Hydatidiform mole.3. Uterine myomas / ovarian cyst.4. Fetal macrosomia (single pregnancy)5. Elevation of the uterus by distended

bladder.

Maternal responses Cardiac output Plasma volume by 1/3 > singletons Red cell mass 300 ml > singletons Pre-eclampsia 5-10 times more Postpartum depression

↓Hematocrit and hemoglobin↓Renal blood flow↓Iron stores

Fetal complicationsFetal complicationsSpontaneous early pregnancy loss rateSpontaneous early pregnancy loss rateDiscordant twinsDiscordant twinsTwin to twin transfusion syndrome (TTTS)Twin to twin transfusion syndrome (TTTS) Intertwining of umbilical cords (monoamniotic Intertwining of umbilical cords (monoamniotic

twins)twins)Conjoined twinsConjoined twinsTwin-reversed arterial perfusion sequence Twin-reversed arterial perfusion sequence

(TRAP) = acardiac twin(TRAP) = acardiac twin Intrauterine growth restriction (IUGR)Intrauterine growth restriction (IUGR) Preterm labourPreterm labour Cerebral palsy > 3 times > in twinsCerebral palsy > 3 times > in twins 10 times > in triplets10 times > in triplets

Acardiac twin weighing 475 grams. The underdeveloped head is indicated by the black arrow. Its viable donor co-twin was delivered vaginally at 36 weeks and weighed 2325 grams.

The perinatal mortalityThe principal causes of fetal death - prematurity, - IUGR - prolapsed cord, - infection, - hypoxia during delivery, - malformations, - transfusion syndrome.

Preterm birth:a- The most common complication of

multiple pregnancies affecting long term outcome.

b- prophylactic use Tocolytics

Bed rest

Cerclage

MANAGEMENT 1. ANTENATAL1. ANTENATAL

2. IN LABOR2. IN LABOR

Early diagnosis (US)(US)Adequate nutrition:

1-1- Caloric consumption increased by 300 Kcal per Caloric consumption increased by 300 Kcal per day.day.2- 2- Iron 60-100 mg per day.Iron 60-100 mg per day.3-3- Folic acid 1mg per day.Folic acid 1mg per day.

Frequent prenatal visits - observe maternal and - observe maternal and fetal complicationsfetal complications1- Frequent ultra sound 1- Frequent ultra sound fetal growth, congenital fetal growth, congenital anomalies, amniotic fluid. anomalies, amniotic fluid. 2- Doppler2- Doppler..

IN LABOR MANAGEMENT Trained obstetrical attendant.Trained obstetrical attendant.

Available blood.Available blood.

Good access I.V line.Good access I.V line.

Cardiotocography monitoring.Cardiotocography monitoring.

Anesthetist.Anesthetist.

Pediatrician for each fetus.Pediatrician for each fetus.

Mode of delivery - presentation of the first baby.Mode of delivery - presentation of the first baby.

IN LABOR MANAGEMENT 40% 40% of of 00P and P and 60% 60% of parous women of parous women

present in labor with a cervix dilated present in labor with a cervix dilated more thanmore than 3 3 cm.cm.

The latent phase is shorter.The latent phase is shorter. The active phase is longer.The active phase is longer. Uterine overdistension ▬ hypotonic Uterine overdistension ▬ hypotonic

uterine dysfunction.uterine dysfunction. Increased risk of postpartum Increased risk of postpartum

hemorrhage (uterine atony).hemorrhage (uterine atony).

Indications for cesarian sectionIndications for cesarian sectionfirst twin presentation other than vertex first twin presentation other than vertex hypotonic uterine dysfunctionhypotonic uterine dysfunction fetal distress fetal distress prolapprolapsedsed umbilical umbilical cord cord prematurity prematurity placenta praevia placenta praevia hypertension induced or aggravated by hypertension induced or aggravated by

pregnancy.pregnancy.

The interval The interval between delivery of the between delivery of the first and second twin is commonly cited first and second twin is commonly cited to be safest if less than to be safest if less than 3030 minutes.minutes.

Internal podalic version – for 2-nd twinInternal podalic version – for 2-nd twin If separation of the placenta is delayed If separation of the placenta is delayed

or bleeding is brisk, extract the placenta or bleeding is brisk, extract the placenta manually after the final delivery.manually after the final delivery.

Postpartum hemorrhage Postpartum hemorrhage is common.is common. Hypotony should be treated promptly Hypotony should be treated promptly

with oxytocin by rapid intravenous with oxytocin by rapid intravenous infusion and massage of the fundus. infusion and massage of the fundus.