MULTIPLE PREGNANCY

Twin pregnancy represents 2 to 3% of all pregnancies.

The PNMR is 5 times that of singleton

DIZYGOTIC TWINS

• Most common represents 2/3 of cases.• Fertilization of more than one egg by more

than one sperm.• Non identical ,may be of different sex.• Two chorion and two amnion.• Placenta may be separate or fused.

Factors affecting it’s incidence

• Induction of ovulation, 10% with clomide and 30% with gonadotrophins.

• Increase maternal age ? Due to increase gonadotrophins production.

• Increases with parity.• Heredity usually on maternal side.• Race; Nigeria 1:22 North America 1:90.

MONOZYGOTIC TWINS

• Constant incidence of 1:250 births.• Not affected by heredity.• Not related to induction of ovulation.• Constitutes 1/3 of twins.

Results from division of fertilized egg:0-72 H. Diamniotic dichorionic.

4-8 days Diamniotic monochor.

9-12 days Monoamnio.monochor.

>12 days Conjoined twins.

MONOZYGOTIC TWINS

• 70% are diamniotic monochorionic.

• 30% are diamniotic dichorionic.

Determination of zygosity

• Very important as most of the complications occur in monochorionic monozygotic twins.

During pregnancy by USS

• Very accurate in the first trimester, two sacs, presence of thick chorion between amniotic memb.

• Less accurate in the second trimester the chorion become thin and fuse with the amniotic memb.

• Different sex indicates dizygotic twins.

• Separate placentas indicates dizygotic twins

Determination of zygozity After Birth

• By examination of the MEMBRANE, PLACENTA,SEX , BLOOD group .

• Examination of the newborn DNA and HLA may be needed in few cases.

COMPLICATIONS OF MULTIPLE PREGNANCY

A] MATERNAL:

1. Anemia due to increase demand.

2. Increase incidence of PET(5 times).

3. Polyhydramniose in monochorionic monozygotic twins.

4. Increase incidence of premature labour.

5. Increase incidence of CS. And operative delivary.

6. Increase incidence of placenta previa and abruptio placenta.

7. Increase incidence of atonic postpartum hemorrhage.

B] FETAL :

1. Increase perinatal morbidity and mortality.

2. Prematurity with or without rupture of membrane.

3. Increase incidence of malpresentation.

4. Increase incidence of cord prolapse.

5. Higher incidence of IUGR.

6. Increase incidence of congenital anomalies.

Specific Complications in Monochorionic Twins

A] TWIN-TWIN transfusion.• Results from vascular anastemosis

between twins vessels at the placenta.• Usually arterio (donor) venous (recipient).• Occurs in 10% of monochorionic twins.

• Chronic shunt occurs ,the donor bleeds into the recipient so one is pale with oligohydraminose while the other is polycythemic with hydraminose.

• If not treated death occurs in 80-100% of cases.

Possible methods of treatment:

• Repeated amniocentesis from recipient.• Indomethacin.• Fetoscopy and laser ablation of

communicating vessels.

• B] Congenital malformation. Twice that of singleton.

• C] Umbilical cord anomalies. In 3 – 4 %.

• D] Conjoined twins. Rare 1:70000 deli varies. The majority are thoracopagus.

• PNMR of monochorionic is 5 times that of dichorionic twins(120 VS 24/ 1000 births)

Maternal Physiological Adaptation

Increase blood volume and cardiac output.Increase demand for iron and folic acid.Maternal respiratory difficulty.Excess fluid retention and edema.Increase attacks of supine hypotension.

DIAGNOSIS OF MULTIPLE PREGNANCY

+ve family history mainly on maternal side.+ve history of ovulation induction.Exaggerated symptoms of pregnancy.Marked edema of lower limb.Discrepancy between date and uterine

size.Palpation of many fetal parts.

Auscultation of two fetal heart beats at two different sites with a difference of 10 beats

USS

Two sacs by 5 weeks by TV USS.Two embryos by 7 weeks by TV USS.

Antenatal Care

AIM

• Prolongation of gestation age, increase fetal weight.

• Improve PNM and morbidity.• Decrease incidence of maternal

complications.

Antenatal Care

Follow Up

• Every two weeks.• Iron and folic acid to avoid anemia.• Assess cervical length and competency.

Antenatal Care

Fetal Surveillance

• Monthly USS.from 24 weeks to assess fetal growth and weight.

• A discordinate weight difference of >25% is abnormal (IUGR).

• Weekly CTG from 36 weeks.

Method Of Delivary

Vertex- Vertex (50%) • Vaginal delivary, interval between twins

not to exceed 20 minutes.

Vertex- Breech (20%)

Vaginal delivary by senior obstetrician

Method Of Delivary

Breech- Vertex( 20%)• Safer to deliver by CS to avoid the rare

interlocking twins( 1:1000 twins ).

Breech-Breech( 10%)• Usually by CS.

Perinatal Outcome

• PNMR is 5 times that of singleton (30-50/1000 births).

• RDS accounts for 50% 0f PNMR.2nd twin is more affected.

• Birth truma . 2ND twin is 4 times affected than 1st .

• Incidence of SB is twice that of singleton.

Perinatal Outcome

• Congenital anomalies is responsible for 15% of PNMR.

• Cerebral hemorrage and birth asphyxia are responsible for 10% of PNMR.

• Cerebral palsy is 4 times that of singleton .• 50% of twins babies are borne with low

birth(<2500 gms.) from prematurity & IUGR.

INTRAUTERINE DFATH OF ONE TWIN

Early in pregnancy usually no risk.

In 2nd or 3rd trimester:• Increase risk of DIC .• Increase risk of thrombosis in the a live

one• The risk is much higher in

monochorionic than in dichorionic twins

• The a life baby should be delivered by 32-34 weeks in monochorionic twins.

HIGH RANK MULTIPLE GESTATION

• Spontaneous triplets 1:8000 births.• Spontaneous quadruplets 1:700,000

births.• The main risk is sever prematurity .• CS is the usual and safe mode of delivary.• High PNMR of 50-100 / 1000 births