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Effects of pregnancy. Exacerbation of common disorders. The presence of more than one fetus in utero and the higher levels of circulating hormones ohen exacerbate the common disorders of pregnancy.
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Exacerbation of common disorders • The presence of more than one fetus in utero and the higher levels of circulating hormones ohen exacerbate the common disorders of pregnancy. • - Sickness, nausea and heartburn may be more persistent and more troublesome than in a singleton pregnancy.
Anaemia • -Iron and folic acid deficiency anaemias are common in twin pregnancies. • Early growth and development of the uterus and its contents make greater demands on the maternal iron stores; in later pregnancy (aher the 28th week), fetal demands may lead to anaemia. • Routine oral iron supplementation remains a controversial issue), but all pregnant women are advised to take folic acid daily
Polyhydramnios • This is also common and is particularly associated with monochorionic twins and with fetal abnormalities. • -Polyhydramnios will add to any discomfort that the woman is already experiencing. • - If acute polyhydramnios occurs, it can lead to miscarriage or preterm labour.
Pressure symptoms • -The increased weight and size of the uterus and its contents may be troublesome. • -Impaired venous return from the lower limbs increases the tendency to varicose veins and oedema of the legs. • -Backache is common and the increased uterine size may also lead to marked dyspnoea and indigestion.
Other • There can be an increase in complications of pregnancy such as obstetric cholestasis, and pelvic girdle pain (PGP)
Labour and the birth • Onset • -The more fetuses the woman is carrying, the earlier labour is likely to start. • - Twins are usually born around 37 weeks rather than 40 weeks, • -approximately 60% of twins are born spontaneously before 37 weeks' gestation. • -In addition to being preterm, the babies may be small for gestational age (SFGA) and therefore prone to the associated complications of both conditions. • - If spontaneous labour begins before 24 weeks, the chances of survival outside the uterus are very small, but it is possible the woman can be given drugs to inhibit uterine activity.
Causes of preterm labour must, if at all possible, be diagnosed and treated quickly; for example, urinary tract infection should be treated with antibiotics. • Antenatal corticosteroids are usually given to all women of multiple pregnancies before 36 weeks' gestation • Evidence shows that aher 38 weeks' gestation there is increased risk of higher mortality in babies • most obstetricians advise induction of labour by 38 weeks for dichorionic twins and between 36 and 37 weeks for monochorionic twins .
In dichorionic pregnancies, • if the first twin is a cephalic presentation, labour is usually allowed to continue to a vaginal birth, but if the first twin is presenting in any other way, an elective caesarean section (CS) is usually recommended
For uncomplicated monochorionic twin pregnancies women are generally offered a vaginal birth, • for complicated monochorionic pregnancies birth is by elective CS. • For triplets and above, the mode of birth is almost always by CS.
ca se hist o r y 1 • C A 34-year-old primigravida was diagnosed with DCDA twins, no family history, so it was a complete shock. At the ultrasound department, a leaflet with local twin organizations and contacts was given to the mother. Through the hospital specialist, multiple birth midwife and twins club the mother started to come to terms with the prospect of twins. • She knew she was expecting two boys and began to wonder if they were identical or not, but would have to wait until they were born and have DNA tests if they looked alike. • She had a straightforward birth with her first child, so she was keen to have a vaginal birth again, but felt there was pressure on her to have an elective caesarean section.
The pregnancy progressed normally and with support from the specialist midwife, she wrote her birth plan. The presenting baby was cephalic, and at 38 weeks labour was induced. • The woman had an epidural and progressed to birth both babies vaginally aher a short labour. • Both babies were put to her breast in the labour suite; twin one sucked well but twin two was not interested. • As establishing • feeding was more problematic than she expected and she felt she needed a lot of help from the midwives, the mother stayed in hospital until day 5. Both babies were sucking well on return home, although twin two did occasionally need a ‘top up’ from the bottle.
Management of labour • -During antenatal classes the couple must be warned that a multiple birth is less common and therefore, for educational purposes in the hospital setting, a number of professionals may ask to observe the birth. • If the woman has any objection to this, her wishes must be respected and a record made in her notes that she wants only those concerned with her care to be present. • Home births are not advisable with a multiple pregnancy, but some women may still request one, in which case every effort should be made to support her decision with an uncomplicated pregnancy.
This will require meticulous risk assessment and planning, including the involvement of midwifery supervision in order that a plan of care for labour is clearly articulated and documented in the woman's records. • A skilled team of midwives with confidence to deliver intrapartum care to women with twin • pregnancies at home will need to be identified to be on call.
The majority of women expecting twins will go into labour spontaneously. • Theoretically the duration of the first stage of labour should be no different from that of a single pregnancy. • However, there is an increased incidence of dysfunctional labour in twin pregnancies, possibly because of overdistension of the uterus.
reasons for earlier induction of labour • as pregnancy-induced hypertension • obstetric cholestasis • , intrauterine growth restriction (IUGR) • twin-to-twin transfusion syndrome • high risk and continuous electronic fetal heart monitoring (EFM) of both fetuses is advocated. • This can be achieved either with two external transducers or, once the membranes are ruptured, a scalp electrode on the presenting twin and an external transducer on the second.
If a ‘twin monitor’ is available, both heartbeats can be monitored simultaneously to give a more reliable reading. • Uterine activity will also need to be monitored. • If cardiotocography (CTG) is not available (e.g. a home birth), use of hand-held Dopplers may be more pragmatic for structured intermifent fetal heart rates (FHRs) auscultation than a Pinard's stethoscope.
-If the lafer has to be used, two people must auscultate simultaneously, so that the two distinct FHRs are counted over the same minute. • While in labour, the woman should be encouraged to adopt whichever position she finds most comfortable. • -A foam rubber wedge under the side of the mafress will help to prevent supine hypotensive syndrome by giving a lateral tilt.
- It may be preferable for her to adopt a leh lateral position, well supported by pillows or a beanbag. • -A birthing chair or a reclining chair, if available, may be more comfortable than a conventional labour suite birthing bed. • -Regional epidural block provides excellent analgesia, and if necessary, allows easier instrumental births and also manipulation of the second twin. • The use of Entonox analgesia may be helpful, either before the epidural is in situ or during the second stage, if the effect of the epidural is wearing off.
The woman should be encouraged to use whatever form of relaxation she finds helpful. • If she chooses to use pharmacological means of analgesia only aher non-pharmacological methods are no longer effective, her wishes should be respected. • The midwife should explain that, if complications arise, intervention and the use of pharmacological analgesia might be necessary. • Ideally this should be discussed with the woman antenatally so that the physiology of labour is not disturbed with new information
If fetal compromise occurs during labour, the birth will need to be expedited, usually by CS. Action may also need to be taken if the woman's condition gives cause for concern. • -If uterine activity is poor, the use of intravenous oxytocin may be required once the membranes have been ruptured. • -Artificial rupture of the membranes (ARM) may be • sufficient to stimulate good uterine activity
it may need to be used in conjunction with intravenous oxytocin. • The CTG will give a good indication of the pafern of uterine activity, whether the labour is induced or spontaneous. • The response of the fetal hearts to uterine contractions can be observed on the CTG. • If the babies are expected to be preterm, low birth weight, or known to have any other problems, the neonatal intensive care unit (NICU) must be informed that the woman is in labour so they can make the necessary preparations to receive the babies.
-When birth is imminent, the paediatric team should be summoned. • -Throughout labour, the emotional and general physical condition of the woman must be considered. • - She requires the presence of her birthing partner and one-to-one care from the midwife.
Management of the birth • -The onset of the second stage of labour should be confirmed by a vaginal examination. • -In the hospital sefing, the obstetrician, paediatric team and anaesthetist should be present for the birth as there is a risk of complications. • - • Epidural analgesia may need to be ‘topped up’ prior to the birth. • The possibility of emergency CS is ever present and the operating theatre should be ready to receive the mother at short notice. • Monitoring of both FHRs should continue until birth. • Provided that the first twin is presenting by the vertex, the birth can be expected to proceed normally, as with a singleton pregnancy.
When the first twin is born, the time of birth and the sex are noted. • This baby and cord must be labelled as ‘twin one’ immediately. • The identity tags should be checked with the mother or father before they are applied to the baby in accordance with local policy. • The baby may be given to the mother for skin- to-skin contact and encouraged to go to the breast as sucking stimulates uterine contractions
Aher the birth of the first twin, abdominal palpation is made to ascertain the lie, presentation (in the event of doubt a portable ultrasound machine should be available) and position of the second twin and to auscultate the FHR to ensure continuous EFM. • An assistant may need to stabilize the lie of the second twin.
If the lie is not longitudinal, an afempt may be made to correct it by external cephalic version (ECV) • ECV in this context in the UK should only be performed or supervised by a senior obstetrician). • ECV is less invasive than internal podalic version, and will often be the default manoeuvre employed by obstetricians
-If it is longitudinal, a vaginal examination is made to confirm the presentation. • -If the presenting part is not engaged it should be gently guided into the pelvis and kept in place until it firmly engages. • -ARM must not be performed on the second sac of membranes until the presenting part engages, as risk of cord prolapse is ever present. • -The FHR must be auscultated again; • -a scalp electrode might be required following ARM if external monitoring of the FHR is of poor quality
-If uterine activity does not recommence, intravenous oxytocin may be used. • -When the presenting part becomes visible, the mother should be encouraged to birth • after second twin with contractions. • -The midwife should always be aware there is a risk the placenta may start to separate before the birth of the second twin, causing oxygen deprivation.
-The birth will proceed as normal if the presentation is vertex, but if the fetus presents by the breech and the midwife is not experienced in breech births she will need a doctor's assistance. • -The birth of the second twin should ideally be completed within 45 minutes of the first twin but, as long as there are no signs of fetal compromise in the second twin, it may be allowed to continue longer.
-If there are signs of compromise, the birth must be expedited and the second twin may need to be born by CS. • -An uterotonic drug (Syntometrine or oxytocin) is usually given intramuscularly or intravenously, depending on local policy, aher the birth of the anterior shoulder as with a singleton pregnancy. • This baby and cord are labelled as ‘twin two’.
The time of birth and sex of child must be noted. • If either twin needs to be transferred to the NICU for observation, the mother should have a chance to see and hold the baby whenever possible. • -Once the uterotonic drug has taken effect, controlled cord traction is applied to both cords simultaneously to aid birth of the placentas without delay. • -Emptying the uterus enables bleeding to be controlled and postpartum haemorrhage prevented.
-The placenta(s) should be examined not only to check completion but the number of amniotic sacs, chorions and placentas noted (see Fig. 14.2). • -If the babies are of different sexes, they are dizygotic. • - If the placenta is monochorionic (MCDA), they must be monozygotic. • -If they are of the same sex and the placenta is dichorionic (DCDA), then further tests will be needed (see Zygosity). • - The umbilical cords should also be examined and the number of cord vessels and the presence of any abnormalities noted.