Multiple pregnancyMultiple pregnancy

• -The term -The term ‘‘multiple pregnancymultiple pregnancy’’ is is used to describe the development of used to describe the development of more than one fetus more than one fetus in uteroin utero at the at the same time.same time.

• - The rise in treatments for infertility - The rise in treatments for infertility such as IVF and ovulation-stimulating such as IVF and ovulation-stimulating drugs, like clomifene citrate and drugs, like clomifene citrate and gonadotrophins.gonadotrophins.

• Twin pregnancyTwin pregnancy• --Types of twin pregnancyTypes of twin pregnancy• 1-monozygotic1-monozygotic (MZ) (MZ)• 2-dizygotic2-dizygotic (DZ). (DZ).• 1- Monozygotic or uniovular twins are also referred to as 1- Monozygotic or uniovular twins are also referred to as ‘‘identical twinsidentical twins’’. .

• -They develop from the fusion of one oocyte and one -They develop from the fusion of one oocyte and one spermatozoon, spermatozoon,

• - after fertilization splits into two.- after fertilization splits into two.• - These twins will be of the same sex and have the same - These twins will be of the same sex and have the same

genes, blood groups and physical features, such as eye and genes, blood groups and physical features, such as eye and hair colour, ear shapes and palm creases. hair colour, ear shapes and palm creases.

• -However, they may be of different sizes and often have -However, they may be of different sizes and often have very different personalities and characters.very different personalities and characters.

Dizygotic or binovular Dizygotic or binovular twinstwins::

• develop from two separate oocytes develop from two separate oocytes that are fertilized by two different that are fertilized by two different spermatozoa,spermatozoa,

• - often referred to as - often referred to as ‘‘non-identical non-identical twinstwins’’. .

• -They are no more alike than any -They are no more alike than any brother or sister and can be of the brother or sister and can be of the same or different sex. same or different sex.

• --

• Because in any pregnancy there is a 50:50 Because in any pregnancy there is a 50:50 chance of a girl or boy, half of dizygotic chance of a girl or boy, half of dizygotic twins will be boy-girl pairs.twins will be boy-girl pairs.

• - A quarter of dizygotic twins will be both - A quarter of dizygotic twins will be both boysboys

• - a quarter both girls. - a quarter both girls. • - two-thirds will be dizygotic and one-third - two-thirds will be dizygotic and one-third

monozygotic.monozygotic.• - one-third of twins are girls, one-third - one-third of twins are girls, one-third

boys and one-third girl-boy pairs.boys and one-third girl-boy pairs.

Determination of zygosity and Determination of zygosity and chorionicitychorionicity• Midwives must understand the differences between the two Midwives must understand the differences between the two

terms and why it is important.terms and why it is important.• Dichorionic :Two placenta, Two chorionsDichorionic :Two placenta, Two chorions• Monochorionic: One placenta, One chorionMonochorionic: One placenta, One chorion• -Determination of zygosity means determining whether or -Determination of zygosity means determining whether or

not the twins are monozygotic (identical) or dizygotic (non-not the twins are monozygotic (identical) or dizygotic (non-identical). identical).

• - By the age of two, parents will know their children so well - By the age of two, parents will know their children so well and see the differences in character and personalities that and see the differences in character and personalities that they find it difficult to believe they can be identical.they find it difficult to believe they can be identical.

• - At birth, monochorionic twins tend to have a greater - At birth, monochorionic twins tend to have a greater weight variation than dichorionic ones.weight variation than dichorionic ones.

- - monozygotic twinsmonozygotic twins::

• - a monochorionic diamniotic - a monochorionic diamniotic placenta (MCDA) placenta (MCDA)

• - the placenta will have two - the placenta will have two chorions and two amnions chorions and two amnions (DCDA),(DCDA),

••

MCMA conjoined twins can develop MCMA conjoined twins can develop

Chorionicity: why is it Chorionicity: why is it important to knowimportant to know??

• - monochorionic twin pregnancies have a 3- monochorionic twin pregnancies have a 3––5 times higher risk of perinatal mortality and 5 times higher risk of perinatal mortality and morbidity than dichorionic twin pregnancies morbidity than dichorionic twin pregnancies

• 1-the chorionicity is determined by 1-the chorionicity is determined by ultrasound examination. ultrasound examination.

• -- The chorions forming the septum between The chorions forming the septum between the amniotic sacs can be seen more clearly the amniotic sacs can be seen more clearly in the first trimester of pregnancy in the first trimester of pregnancy

• If the septum has thickness of 2.4mm or If the septum has thickness of 2.4mm or more, a dichorionic twin pregnancy;more, a dichorionic twin pregnancy;

• - if it is a thin septum thickness of 1.4mm, - if it is a thin septum thickness of 1.4mm, a monochorionic pregnancy a monochorionic pregnancy

• -2- studying the septum at its base. -2- studying the septum at its base.

• -A tongue of placental tissue is seen -A tongue of placental tissue is seen ultrasonically between the two chorions ultrasonically between the two chorions and this is termed the and this is termed the ‘‘twin peaktwin peak’’ or or ‘‘lambda signlambda sign’’

Zygosity determination Zygosity determination after birthafter birth• @-DNA accurate method. @-DNA accurate method. • -The DNA can be extracted from cells taken from a -The DNA can be extracted from cells taken from a

cheek swab from inside the mouth (buccal cavity ). cheek swab from inside the mouth (buccal cavity ). • -@genetic markers 99.99% accurate.-@genetic markers 99.99% accurate.• - Zygosity determination should be routinely offered - Zygosity determination should be routinely offered

to all same-sex twins for the following reasons:to all same-sex twins for the following reasons:• ••1-1- Most parents will want to know whether or not Most parents will want to know whether or not

their twins are identical,: their twins are identical,: ‘‘Are they identical?Are they identical?’’; also as ; also as the twins get older they usually want to know.the twins get older they usually want to know.

• •• 2- considering further pregnancies, they will 2- considering further pregnancies, they will want to know the risk of having twins again.want to know the risk of having twins again.

• --

• DZ twins tend to run in families DZ twins tend to run in families • -usually on the female side ,though not in all cases. -usually on the female side ,though not in all cases. • -MZ twins do not run in families -MZ twins do not run in families • ••3-3- It will help the twins in establishing their sense It will help the twins in establishing their sense

of identity; of identity; • -4-it will influence their life and family relationships.-4-it will influence their life and family relationships.• ••5-5- The information is important for genetic The information is important for genetic

reasons, not just with monogenic disorders but with reasons, not just with monogenic disorders but with any serious illness later in life.any serious illness later in life.

• •• 6-Twins are frequently asked to be involved in 6-Twins are frequently asked to be involved in research where knowledge of zygosity is essential research where knowledge of zygosity is essential

Diagnosis of twin Diagnosis of twin pregnancypregnancy• -ultrasound examination.-ultrasound examination.• - 6 weeks - 6 weeks • -20th and 22nd weeks. -20th and 22nd weeks. • -When booking a woman in the antenatal clinic a family -When booking a woman in the antenatal clinic a family

history of twins should alert the midwife to the possibility of history of twins should alert the midwife to the possibility of a multiple pregnancy.a multiple pregnancy.

• - If the pregnancy is diagnosed at 6 weeks, the woman - If the pregnancy is diagnosed at 6 weeks, the woman should be told about should be told about ‘‘vanishing twin syndromevanishing twin syndrome

• -Occasionally one fetus may die in the second trimester and -Occasionally one fetus may die in the second trimester and become a fetus papyraceous,which then becomes become a fetus papyraceous,which then becomes embedded in the placenta and expelled with the placenta embedded in the placenta and expelled with the placenta at delivery. at delivery.

• -This is very rare -This is very rare

Abdominal examinationAbdominal examinationInspectionInspection

• -On inspection, the size of the uterus may -On inspection, the size of the uterus may be larger than expected for the period of be larger than expected for the period of gestation, particularly after the 20th week. gestation, particularly after the 20th week.

• -The uterus may look broad or round and -The uterus may look broad or round and fetal movements may be seen over a wide fetal movements may be seen over a wide area, area,

• -although the findings are not diagnostic of -although the findings are not diagnostic of twins.twins.

• - Fresh striae gravidarum may be apparent. - Fresh striae gravidarum may be apparent.

• - the amount of amniotic fluid is normal in a twin - the amount of amniotic fluid is normal in a twin pregnancy but polyhydramnios is common pregnancy but polyhydramnios is common

• complication of a twin pregnancy, particularly complication of a twin pregnancy, particularly with monochorionic twins.with monochorionic twins.

• PalpationPalpation• - the fundal height may be greater than expected - the fundal height may be greater than expected

for the period of gestation.for the period of gestation.• - The presence of two fetal poles (head or breech) - The presence of two fetal poles (head or breech)

in the fundus of the uterus may be revealed on in the fundus of the uterus may be revealed on palpation and multiple fetal limbs may also be palpation and multiple fetal limbs may also be palpable.palpable.

• - The head may be small in relation - The head may be small in relation to the size of the uterus and may to the size of the uterus and may suggest that the fetus is also small suggest that the fetus is also small and that there may therefore be and that there may therefore be more than one present. more than one present.

• -Lateral palpation may reveal two -Lateral palpation may reveal two fetal backs or limbs on both sides.fetal backs or limbs on both sides.

AuscultationAuscultation

• -Hearing two fetal hearts is not -Hearing two fetal hearts is not diagnostic as one can often be heard diagnostic as one can often be heard over a wide area in a singleton over a wide area in a singleton pregnancy. pregnancy.

• -If simultaneous comparison of the -If simultaneous comparison of the heart rates reveals a difference of at heart rates reveals a difference of at least 10 b.p.m., it may be assumed least 10 b.p.m., it may be assumed that two hearts are being heard.that two hearts are being heard.

The pregnancyThe pregnancy

• A multiple pregnancy tends to be A multiple pregnancy tends to be shorter than a single pregnancy. shorter than a single pregnancy.

• The average gestation for twins is 37 The average gestation for twins is 37 weeks, for triplets 34 weeks and for weeks, for triplets 34 weeks and for quadruplets, 33 weeksquadruplets, 33 weeks

• ..

Effects of pregnancyEffects of pregnancy

• Exacerbation of common disordersExacerbation of common disorders• - Sickness, nausea and heartburn may be more persistent - Sickness, nausea and heartburn may be more persistent

and more trouble.and more trouble.• AnaemiaAnaemia• -Iron deficiency-Iron deficiency• - folic acid deficiency anemia are common in twin - folic acid deficiency anemia are common in twin

pregnancies. pregnancies. • -Routine oral iron supplementation remains a controversial -Routine oral iron supplementation remains a controversial

issueissue• PolyhydramniosPolyhydramnios• -common with monochorionic twins and with fetal -common with monochorionic twins and with fetal

abnormalities. abnormalities. • -add discoamfort to woman -add discoamfort to woman • -If acute polyhydramnios occurs, it can lead to miscarriage or -If acute polyhydramnios occurs, it can lead to miscarriage or

premature labor.premature labor.

Pressure symptomsPressure symptoms

• -The increased weight and size of the -The increased weight and size of the uterus .uterus .

• -Impaired venous return from the -Impaired venous return from the lower limbs increases the tendency to lower limbs increases the tendency to varicose veins and edema of the legs.varicose veins and edema of the legs.

• - Backache is common- Backache is common• - increased uterine size may also lead - increased uterine size may also lead

to marked dyspnoea and indigestion.to marked dyspnoea and indigestion.

Antenatal screeningAntenatal screening

• The recommended method of screening is by The recommended method of screening is by measurement of the nuchal translucency,measurement of the nuchal translucency,

• - biochemistry - biochemistry • •• Nuchal translucency for Down Nuchal translucency for Down

syndrome is accurate between 11 and 13 syndrome is accurate between 11 and 13 weeks weeks

• •• Chorionic villi sampling (CVS) is not Chorionic villi sampling (CVS) is not usually recommended in multiple pregnancy usually recommended in multiple pregnancy as loss rates are high.as loss rates are high.

• •• Amniocentesis can be performed in Amniocentesis can be performed in twin pregnanciestwin pregnancies

• between 15 and 20 weeks.between 15 and 20 weeks.• It should be performed in a specialist It should be performed in a specialist

fetal medicine unit.fetal medicine unit.• Most obstetricians prefer to do a dual Most obstetricians prefer to do a dual

needle insertion so there is no chance needle insertion so there is no chance of contamination between the two of contamination between the two sacs.sacs.• •• Chorionicity should be Chorionicity should be

determined in the first trimester.determined in the first trimester.

• All monozygotic twins should have All monozygotic twins should have echocardiography performed at echocardiography performed at approximately 24 weeks' gestation,approximately 24 weeks' gestation,

• - higher risk of cardiac anomalies in - higher risk of cardiac anomalies in these babies. these babies.

Ultrasound examinationUltrasound examination

• Monochorionic twin pregnancies should be Monochorionic twin pregnancies should be scanned every 2 weeks from diagnosis to scanned every 2 weeks from diagnosis to check for discordant fetal growth and signs check for discordant fetal growth and signs of twin-to-twin transfusion syndrome (TTTS). of twin-to-twin transfusion syndrome (TTTS).

• -A cardiac anomaly scan should be -A cardiac anomaly scan should be performed at 24 weeks.performed at 24 weeks.

• •• Dichorionic twin pregnancies should be Dichorionic twin pregnancies should be scanned at 20 weeks for anomalies, , and scanned at 20 weeks for anomalies, , and then usually every 4 weeks.then usually every 4 weeks.

Antenatal preparationAntenatal preparation

• Early diagnosis of a twin pregnancy Early diagnosis of a twin pregnancy and of chorionicity is extremely and of chorionicity is extremely important.important.

• Parent educationParent education

• -When a multiple pregnancy is -When a multiple pregnancy is diagnosed, written information on diagnosed, written information on multiple pregnancy should be given multiple pregnancy should be given to the mother. to the mother.

• -This should include contact phone -This should include contact phone numbers of any local support numbers of any local support organizationsorganizations

• - the midwife should give them the - the midwife should give them the opportunity to discuss any worries or opportunity to discuss any worries or problems they may have, as two babies problems they may have, as two babies will add a considerable financial burden will add a considerable financial burden to any family's income to any family's income

Preparation for Preparation for breastfeedingbreastfeeding• -focus on nutritional need of the mother -focus on nutritional need of the mother

• - Mothers should be encouraged that it is - Mothers should be encouraged that it is possible to breastfeed two, and in some possible to breastfeed two, and in some cases three babies.cases three babies.

• -Early in the antenatal period the mother -Early in the antenatal period the mother should be given as much information and should be given as much information and advice as possible about both breast- and advice as possible about both breast- and bottle-feeding, so she can make an bottle-feeding, so she can make an informed choice on how to feed her babiesinformed choice on how to feed her babies

Topics for parent education Topics for parent education classesclasses

• Facts and figures on twins and twinningFacts and figures on twins and twinning• •• Diet and exerciseDiet and exercise• •• Parental anxieties about obstetric Parental anxieties about obstetric

complicationscomplications• •• Labour, pain relief and the birthLabour, pain relief and the birth• •• Possibilities of premature labour and Possibilities of premature labour and

birth and the outcomebirth and the outcome• •• Visit to the neonatal unitVisit to the neonatal unit• ••

• Breastfeeding and bottle-feedingBreastfeeding and bottle-feeding

• •• ZygosityZygosity

• •• Coping with newborn twins or Coping with newborn twins or moremore

• •• Development of twins including Development of twins including individuality and identityindividuality and identity

• •• Sources of help.Sources of help.

• . .

Thank youThank you