Shagufta Naz08-176

Batch-KFinal Year MBBS

DefinitionThe period from conception to birth. After the egg is fertilized by a sperm and then implanted in the lining of the uterus, it develops into the placenta and embryo, and later into a fetus

Multiple pregnancy describes a pregnancy comprising of more than one fetus.

Classification:Classification of multiple pregnancy is

based on: Number of fetuses: twins, triplets Number of fertilized eggs: zygosity Number of placantae : chorionicity Number of amniotic cavities: amnionicity

Twin pregnancy

means that a woman

is carrying two fetuses

at a time.

Incidence: 2-3% of all

pregnancies.

Types:

Dizygotic twins

Monozygotic twins

Dizygotic twins also called bin ovular, fraternal or unlike twins.

Dizygotic twins results when two oocytes are simultaneously released from the same or both ovaries and fertilized by two separate spermatazoa derived at same coitus.

Incidence of dizygotic twin is 75% of all twin pregnancies.

Dizygotic twins have different genetic constitutions and have no special resemblance.

They may have same or different blood groups as well as the gender.

Within uterine cavity the two the two zygote implant separately each having its own set of placenta and membranes ( dichorionic and diamniotic )

Monozygotic twins also called uni ovular,

identical or like twins.

They originate from the fertilization of single

ovum by a single sperm which subsequently

divides into two.

Incidence of monozygotic twins is constant

worldwide and is said to be 3-4/1000 births.

Within the uterine cavity the arrangement of

placenta and membranes for the monozygotic

twins varies greatly and depends upon the time

interval between the fertilization and division of

zygote.

Sooner the division occurs more independent the

twins are, & the dependence over each other &

hence the complication rate increases with the

prolongation of interval between fertilization and

division.

Age: incidence increases with increasing

maternal age, with peak at 37-38years

Parity: multipara are more likely to have

twin pregnancy.

Race: incidence varies among different

races;

2/1000 births in Japan

3/1000 births in Asians

49/1000 births in Nigeria

Recurrence: The incidence of dizygotic twin pregnancy increases 10 fold after one dizygotic twin pregnancy.

Family History: Positive family history also cause high incidence.

Built: Tall and Fat women are more likely to have twins as they are generally better nourished, and twinning is less often in under nourished women.

Fertility Drugs: incidence is 8% in patients

receiving clomiphene and 20% with menopausal

gonadotroin .

Role of LH and FSH: High levels of LH and FSH

lead to multiple ovulation. High levels of

gonadotrophins are found in advance age,

obesity, and after treatment with fertility drugs.

Moreover low level of gonadotrophin in

Japanese and low incidence of twin pregnancy.

Maternal Complications:

Hyper emesis gravidarum

Anemia

Pregnancy induced hypertension

Urinary tract infections

Placental abruption

Operative delivery

Postpartum hemorrhage

Pressure symptoms:

Backache

Dyspnea and dyspepsia

Supine hypotension syndrome

Lower limb edema and varicosities

Other maternal complications:

Excessive weight gain, 16-20kg

Placenta previa

Diabetes mellitus

Congenital malformations:

Unique to multiple pregnancy are: conjoined

twins, fetal acardia, symmelia

More common in multiple pregnancy but not

unique to it include: neural tube defects, bowel

atresia, cardiac anomalies, congenital dislocation

of hip joint & certain chromosomal abnormalities.

Polyhydramnios

Twin-to-twin transfusion syndrome (TTTS, also known as Feto-Fetal Transfusion Syndrome (FFTS) and Twin Oligohydramnios-Polyhydramnios Sequence (TOPS)) .

It can affect monochorionic multiples, that is, multiple pregnancies where two or more fetuses share a chorion and hence a single placenta.

Severe TTTS has a 60–100% mortality rate

As a result of sharing placenta

blood supplies of

monochorionic twin fetuses can

become connected, so that

they share blood circulation:

,the connecting blood vessels

within the placenta allow blood

to pass from one twin to the

other.

Depending on the number, type

and direction of the

interconnecting blood vessels

(anastomoses ), blood can be

transferred disproportionately

from one twin (the "donor") to

the other (the "recipient").

Stuck twin phenomenon

Twin reverse arterial perfusion sequence (TRAP

sequence)

Inrauterine growth restriction ( IUGR)

Malpresentations

Preterm labor

Locked twins

Cord accidents & Rupture of membranes in case

of monoamniotic twins

Hydatidiform mole (0.01%)

Combined pregnancy

RH incompatibility: more severe due to

Excessive fetomaternal hemorrhage

Maternal sensitization

Prolonged pregnancy (beyond 39 weeks)

Perinatal mortality in twin gestation is 5 time

higher due to above mentioned risks

Ultrasound : Conclusive : can verify twin pregnancy at 12

weeks.

High HCG Level: Very high level can help in diagnosis but not

conclusive, as singleton pregnancy can also have high levels in some conditions.

Doppler : Baby Doppler detect heartbeat, two individuals

beats can be found.

Signs and symptoms of pregnancy:sign and symptoms of pregnancy are more pronounced, as:

Excessive morning sickness Extreme fatigue Fundal height: large for gestational age Fetal movements: can be felt as early 14 weeks

and excessive as well. Weight gain: average weight gain for twin

pregnancy is about 10 lb more than with a sigleton pregnancy.

Management of multiple pregnancy may include the following:increased nutritionMothers carrying two or more fetuses need more calories, protein, and other nutrients, including iron. Higher weight gain is also recommended for multiple pregnancy. The American College of Obstetricians and Gynecologists recommends women carrying twins gain at least 35 to 45 pounds.

more frequent prenatal visitsMultiple pregnancy increases the risk for complications. More frequent visits may help detect complications early enough for effective closely.

ReferralsReferral to a maternal-fetal medicine specialist, called a perinatologist , for special testing or ultrasound evaluations, and to coordinate care of complications, may be necessary.

Increased restSome women may also need bed rest - either at home or in the hospital depending on pregnancy complications or the number of fetuses

maternal and fetal testingTesting may be needed to monitor the health of the fetuses, especially if there are pregnancy complications.

tocolytic medicationsTocolytic medications may be given, if preterm labor occurs, to help slow or stop contractions. Tocolytic medications often used include terbutaline and magnesium sulfate.

corticosteroid medicationsCorticosteroid medications may be given to help mature the lungs of the fetus.

cervical cerclageCerclage (a procedure used to suture the cervical opening) is used for women with an incompetent cervix. This is a condition in which the cervix is physically weak and unable to stay closed during pregnancy. Some women with higher-order multiples may require cerclage in early pregnancy.

Time of delivery:

Duration of gestation in twin pregnancy is

biologically short, up to 50% of patient deliver

before 37 weeks and after 39 weeks twin

gestation is considered as prolonged, therefore

delivery b/w 37-39 weeks is recommended.

Mode of delivery: Elective caesarean section

Vaginal delivery

Twin pregnancy in the presence of any additional

risk factor should be better delivered by

caesarean section.

Indications: Pregnancy induced hypertension

Diabetes mellitus

Ante partum hemorrhage

Malpresentation of first twin

Conjoined twins

polyhydramnios

In an uncomplicated twin pregnancy with the

first twin in cephalic presentation, vaginal

delivery is the route of choice.

Induction in twins: Labor should not be induced in complicated twin

pregnancy.

Uncomplicated pregnancy with the first twin

presenting as vertex, induction of labor is safe

provided continuous fetal heart monitoring is

ensured.

Management of first stage: Continuous fetal heart rate monitoring

Artificial rupture of membrane

Use of oxytocin

Epidural analgesia

Management of second stage: Delivery of first twin:

if vertex presentation, same principles as for

singleton pregnancy.

After delivery placental side of umbilical cord must be secured properly to avoid hemorrhages in case f monoamniotic twins.

Delivery of second twin: Second twin should better be delivered within 15

minutes of delivery of first twin. If uterine contraction does not resume, ARM is

performed. If flexed or footling breech, feet can be grasped

and pulled down before rupture of membranes to stabilize he lie of baby.

Special circumstances for second twin: If the second twin in vertex presentation fails to

descend, vacuum extraction may be used.

If an abnormal lie is uncorrectable at external

version, internal podalic version may b used.

Caesarean section is indicated if:

Abnormal lie is not corrected at ECV, & IPV is

not feasible.

Membranes are ruptured and liquor drains with

or without cord prolapse .

Management of third stage: Active management with the administration of

oxytocin and even ergometrine if patient is

normotensive .

Patient should be kept under close observation

for any vaginal bleeding as these patients are

more likely to have postpartum hemorrhages.

It results when zygote is divided after 13 days from the time of fertilization.

Incidence: 1:200 monozygotic twins

Conjoined twins share he body parts and severity increase with the delay in division beyond 12 days.

Types: Equal conjoined twins Unequal conjoined twins

Equal conjoined twins: Two individuals of similar development.

Sharing vary from bridge of skin to most vital

parts like liver, heart or even trunk .

Depending upon site of sharing they may be:

Anterior ( thoracopagus )

Posterior ( pyopagus )

Cephalic (craniopagus )

Caudal ( ischiopagus )

Unequal conjoined

twins:

A normal fetus has

additional major parts

attached to it, such as

limbs or there is

development of partial

fetus in the

abdomen(fetus in fetu

)

Diagnosis: Ultrasound

If twins maintain similar relationship to each

other during the whole antenatal period

Delivery: Caesarean section

Treatment: Surgical separation: Depending upon the degree

to which they share their vital organs.