Obstetrics & Gynecology

Multiple Multiple pregnancypregnancy

Prepared by :Prepared by :Murali Krishnan BalakrishnanMurali Krishnan Balakrishnan

Group 607Group 607

Definition: It is the presence of more than one fetus in the

abdomen of a pregnant women.

According to their number, they could be categorized into:

twins (most common), triplet, quadriplet, …etc.

Incidence: ◦According to Hellin's law [1:80 (n-1)]

the incidence of twins is 1:80, for tripalet 1:(80)2, for quadriplet 1:(80)3, and so on. This rule applies for spontaneously occuring multiple

pregnancies and not for those induced by ovulatory stimulating drugs.

Factors that increases incidence of twins:Factors that increases incidence of twins:

-Maternal Parity: Increased fertility of the mother (high parity) g release more than one ovum.

Family history (genetic).Race (blacks> whites >> Asian).Maternal Age > 35 years old.Assisted Reproductive Technology:

◦Ovulation induction agents.◦In vitro fertilization

? maternal body habitus ? h endogenous GnRH levels

TypesTypes

Monozygotic◦ Fertilization of a single ovum,

◦ Similar sex.

◦ Identical in every way including the HLA genes

◦ Not genetically determined

◦ Constant in all races; its prevalence: 1/250.

Dizygotic◦ Fertilization of 2 seperate

ova◦ Its etiology and

prevalence varies, with racial / hereditary difference,

◦ Its actual prevalence is increasing due to: Early diagnosis by U/S. Induction of ovulation Change of the ages of

women experiencing their first pregnancy and delivery ( > 35 years age).

What is meant by Superfetation & superfecundation?

DizygoticMonozygotic= same sex

NB: (chronicity is important in obs.)

monochorionic monoamniotic monochorionic monoamniotic (MCMA)(MCMA)

much less commonhave AA anastomoses,may still occur --will lack the classic sign

of discordant sac size. -The combination of polyhydramnios in

the single amniotic cavity with discordant bladder size is usually sufficient to make the diagnosis

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◦dichorionic/diamniotic (30%)◦Monochorionic/diamniotic (70%)

◦Monochorionic/monoamniotic (1%)

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monoch diaminioticmonoch diaminiotic

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Fundal h. more than dateFundal h. more than date

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Yolk Yolk sacsac

NNutrition & bone marrowutrition & bone marrow

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Appear Appear

1- yolk sac (dignostic)2- embryo disc3- amniotic sac (membrane: u can’t see in

U/S--- see cavity)

NB: chronic sac= gestational sac.

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monochorionic/diamnioticmonochorionic/diamniotic9w9w

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monochorionic/diamaniotic twins monochorionic/diamaniotic twins

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11-14 weeks11-14 weeks

10 weeks10 weeks

History…History…

Patient profile:◦ Etiological factors; with positive past history and

family history specially maternal.Early pregnancy: Hyperemesis, bleeding.Mid-pregnancy:

◦ Greater weight gain than expected, ◦abdominal size > period of amenorrhea, ◦early PIH symptoms, persistent fetal activity.

Late pregnancy: ◦Pressure symptoms (dyspnea, dyspepsia, UTI,

piles, edema and varicose veins in LL).

ExaminationExaminationGeneral:

◦ An early increase weight gain, ◦ Pallor◦ Less mid-trimisteric fall blood pressure◦ Early PIH ◦ Eary edema, and varicose veins in LL.

Abdominal:◦ Fundal level > amenorrhea especially in mid-pregnancy

exclude other causes.◦ Palpation: Multiple fetal parts – 3 poles, 2 heads, small head in

relation to uterine size, fetal movement all over abdomen. identify presentations.

◦ Auscultation of FHS: 2 different recordings by 2 observers and a difference > 10 bpm a

Gallop between 2 points[ Arnoux sign] ECG.

Pelvic: Specially during the course of labor ◦ small presenting part compared to abdominal size

DDDD-T-shape sign: in monochroinic-T-shape sign: in monochroinic

- lambda sign : bulk tissue at junction

Twin peakTwin peakwww.smso.net

Differential diagnosis:Differential diagnosis:

Mistaken date.Polyhydromnios.Fibroid.Hydatidiform mole.Cysts.Retention of urine During

pregnancy it will push the uterus upwards.

 

U/SU/S Gestational sacGestational sac yolk sacyolk sacFH sound- fetal part& headFH sound- fetal part& head--- confirm:--- confirm:1-Twin1-Twin2-Dating2-Dating3- chronicity3- chronicity

At 8w :Fetal heart – 6 w ‘pulsation’

Later:Echo& crown-rumb length13w:Biparital diameterFemur length

4- placental localization5- congenital malformation18w-> CVS anamoly-neural tube- anance.6-presentation7- sex : differ--- dizygotic8-polyhydrominous9- size of baby---- IUGR especialy MCMA10- fetal death ( vanish twin)--- abortion11- complication of twin gestation

complicationcomplication

- during pregnancy

- during labour

- after labour

maternalmaternal

1- Anemia2- hyperemesis gravidarum3- presure symptome4- PIH5- placenta previa6- abruptio7-DM8- Polyhydramnios acutemore in monozygotic9- Psychological:caring, rest&hospitalization

Fetal complicationFetal complication

1- Abortion2- preterm labour3- PROM4- congenital anomalis5- complication of monochroinic twins:A- IUFD b-IUGR C- TTTSD- TRAPS- twin Verse Arterial perfusion

sequence

6- conjoint twin

◦-Death during delivery: first fetus: [prolapsed cord], second fetus: [ due to excess sedation, premature

seperation of placenta, constriction ring ,dystocia, operative manipulation, hypoxia].

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TRAP..??TRAP..??

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Labour riskLabour risk

-PPH- cord prolapse- locked twin- Abnormal fetal presentation -Vasa Praevia (due to vilamentous insertion of

the cord).- Two Vessel cord -Puerperal Sepsis

NORMALRETARD IUGR --- Donor

PolyhydraminousPolscythameiaHypervolumeiaCHFhypertensive,

kernicterus

OligAnemiaHypovolemiaH.FHydrops fetalis

managmentmanagment

-regular ANC visit-iron+ folic + vit. -rest- freq. U/S- try to control problems: PIH, p. loc. , lie

-assistance:(look to 1st twin) =1-presentation 2- accompany complication

1st stage2nd stage: cephalic normal V. D if Breech or Transverse C/S

C.S. for Multiple Pregnancy:C.S. for Multiple Pregnancy:

Indications of C.S. :◦ More than 2 viable fetuses, if:

weight < 2 kg, discordant growth ( i.e.; IUGR or twin-twin transfusion, or

disproportionate twins, twin B larger than A (BPD > 2 mm), twin A: is non-vertex. Conjoined Twins

◦ Single amniotic cavity (as diagnosed by U/S or amniogram).

◦ Previous Uterine scar.◦ During Labor: if delayed progress, fetal distress, or if

twin B transverse and cervix is thickened (retained second twin).

◦ Associated pregnancy complication i.e.; severe PIH, placenta previa.

◦ Contracted Pelvis◦ Lack of expertise

Vaginal Delivery for Multiple PregnancyVaginal Delivery for Multiple Pregnancy

◦ Always perform an episiotomy.

◦ Delivery of twin A (Vertex): with minimal

interference (no artificial rupture of membranes,

no augmentation, avoid difficult forceps or

ventouse), no breech extraction if breech.

◦ On delivery of twin A: Clamp and cut cord of twin A immediately, away from

vulva and mark it.

No ergometrine is given.

Assess twin B (abdominally/vaginally) i.e ; presentation,

position, exclude mono-amniotic pregnancy or cord

prolapse.

◦Delivery of twin B: assess second sac:

◦ if no sac, immediate delivery. ◦ If there is a sac, examine for lie:

If longitudinal, wait 10 min (hasten if fetal distress or bleeding). If inertia, give oxytocin. If the presenting part is high, moderate fundal pressure and artificial rupture of membranes, then ventouse or breech extraction.

If transverse, bring a leg by abdominovaginal manipulation i.e.; external cephalic version (ECV) or internal podalic version (IPV), then breech extraction.

◦Placental delivery and examination for zygosity: If delayed, then do manual removal. Examine placenta for zygosity. Exploration of genital tract for retained products and lacerations.

Guard against postpartum hemorrhage (massage and I.V ecbolics )

Retained Twin BRetained Twin B

The usual time interval between delivery of twin A and B is 15-20 minutes

If there are facilities for proper monitoring this interval may be increased

Indications of CS for Twin B◦Transverse lie◦Fetal Distress◦Contracted cervix◦Prolapsed cord◦Premature Breech◦Failed Extraction

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Hydrops fetalisHydrops fetalis

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Non-immune hydrops fetalisNon-immune hydrops fetalis1.Cardiac failure2.Anemia3.Arteriovenous shunts4.Mediastinal compression5.Metabolic disorder6.Fetal infection/tumor7.Congenital renal/pulmonary/GI/skeletal defect8.Chromosomal anomalies

Twin-to-twin Twin-to-twin transfusion transfusion syndrome (TTTS) syndrome (TTTS)

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PathophysiologyPathophysiology1. Placental architecture 1. Placental architecture

Almost all monochorionic twins have intertwin vascular anastomoses.Arterio-arterial (AA) anastomoses and veno-venous (VV) anastomoses are superficial anastomoses, travelling across the surface of the placenta without interruption between the two cord insertions.

Arterio-venous (AV) anastomoses are deep anastomoses, where an unpaired artery and vein pierce the chorionic plate in close adjacency to supply a shared placental cotyledon. --provide unidirectional flow of blood from the donor to the recipient.

TTTS results from intertwin transfusion across shared placental vascular anastomoses

TTTS occurred uncommonly (15%) despite the high frequency of occurrence of cross-placental vascular communication.

PathophysiologyPathophysiology2. The fetal response 2. The fetal response

Transfusion through the unidirectional AV anastomoses creates hydrostatic differences between the twins.

Atrial natriuretic peptide (ANP) and vasopressin levels in the twins diverge; the donor responds with oliguria, and the recipient with polyuria and polyhydramnios (Quintero stage 1).

The resultant haemoconcentration in the recipient creates an osmotic gradient from the maternal compartment, worsening the polyhydramnios

As donor perfusion pressure continues to fall urine production finally ceases (Quintero stage 2), resulting in a ‘stuck twin’. a

The resultant inability to swallow aggravates the donor twin's hypotension, and vasoconstrictor peptides, such as the renin-angiotensin system (RAS) mediators, increase dramatically increased arterial resistance in the donor's placental territory growth restriction.

Absent or reversed end-diastolic flow (A/REDF) in the donor umbilical artery (UA) may be seen (Quintero stage 3: donor).

These RAS mediators are also transfused to the recipient via placental anastomoses （ similar cord levels of renin and aldosterone despite discordant renal expression of renin between donors and recipients. ）

Systemic hypertension in the recipient fetus, initiated by the increase in cardiac output, now worsens.

[endothelin and fetal natriuretic peptides]: higher in recipient twins--these mediators likely work synergistically to induce pressure-overload cardiomyopathy.

Disease stagingDisease staging

Screening for TTTSScreening for TTTS

1. nuchal translucency2. First trimester ductus venosus (DV)3. Intertwin membrane folding at 15-17 w

Ultrasound picture of a 12-week Ultrasound picture of a 12-week fetus with trisomy 21, fetus with trisomy 21, demonstrating increased nuchal demonstrating increased nuchal translucency thicknesstranslucency thickness

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Diagnosis and assessment of TTTS Diagnosis and assessment of TTTS

Minimum sonographic criteria ：(i) monochorionic twins, that is, single placenta, same sex twins, and absence of intervening chorion (‘twin peak’ sign); (ii) oligohydramnios (maximal vertical pocket (MVP) ≤ 2 cm) in the donor sac; and (iii) polyhydramnios (MVP ≥ 8 cm) in the recipient sac.

Differential diagnoses Differential diagnoses

1. selective (IUGR) also affects 15% of monochorionic twins

2. monochorionic twins discordant for anomaly (particularly renal agenesis) may result in anhydramnios around one twin.

-- neither of these conditions is associated with polyhydramnios in the other twin

tttttt

untreated perinatal mortality for severe midtrimester TTTS is up to 90%.

1. Selective laser photocoagulation (SLPC) of intertwin vascular anastomoses

2. Amnioreduction and septostomy3. cord occlusion in TTTS

Selective cord coagulationSelective cord coagulation

SeptostomySeptostomywww.smso.net

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TTTSTTTS

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Reduction Reduction amniocentesisamniocentesis

Radiofrequency ablationRadiofrequency ablation

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Thank you….Thank you….