Preterm labour and birth, PROM and multiple pregnancy

Question 1

preterm birth

Answer 1

labour that occurs after 20 weeks gestation and before 37 weeks

Question 2

incidence of preterm birth

Answer 2

• 8.5% incidence AUS
• 0.7% were born at <28 weeks (713 babies)
• 0.7% were born at 28-31 weeks (642 babies)
• 6.0% were born at 32-36 weeks (5754 babies)

Question 3

preterm labour and infection

Answer 3

-Inflammatory cytokines or bacterial endotoxins can stimulate prostaglandin release directly or indirectly by stimulating the release of corticotrophin-releasing hormone (CRH).
-Infection may be predictive as a marker in preterm birth at least 40% of the time.
-Continuing rise in the incidence of sexually and non-sexually transmitted infections.
-The development of microbial resistance to antibiotics

Question 4

preterm labour risk factors

Answer 4

-Past obstetric history: risk of repeated preterm delivery after one = 15%, two = 41%, prior pregnancy losses and previous abortions and the number of these.
-Births following ART and ovulation induction. In Australia, 1.7% of all births followed assisted conception in 1999-2000, and multiple births occurred in 20.9% of the viable pregnancies from assisted conception.
-Increasing proportion of births among women > 34 years.
-Infections: bacterial vaginosis, UTI.
-Demographic: relative social disadvantage is one of the most consistent findings in the preterm birth literature.
-Medical conditions: diabetes, high blood pressure, heart disease.
-Current pregnancy: pre-eclampsia, major birth defects, placental abruption.
-Behavioural i.e. stress, psychological issues.
-Environmental

Question 5

cervical assessment

Answer 5

• Used with women who have a history of preterm birth, second trimester miscarriages, current risk of preterm birth, twins and those who have had cervical surgery.
• Ultrasound surveillance of the length of the cervix to check for shortening and dilatation.
• Assessment by experienced sonographers to determine if cervical cerclage is warranted*. NB: risk of infection, PROM.
• U/S frequency dependent on obstetric history.
• Cervical length varies according to gestation and a short cervix is a risk for preterm birth. No intervention required if the cervix is > 25mm.

Question 6

fetal fibronectin testing (FFT)

Answer 6

• Singleton pregnancy.
• 24-34 completed weeks.
• TPL-regular uterine contractions > 6 per hour and/or pelvic pressure and in those women who are asymptomatic but at high risk of preterm delivery.
• Intact membranes. NB: blood and amniotic fluid contain fFN.
• Cervix ≤ 3cm dilatation and no cerclage.
• Established fetal wellbeing

Question 7

negative fFN

Answer 7

A negative fFN test makes it possible to:
Avoid unnecessary hospitalisations, testing and reduces interventions.
Reassure the woman that they are unlikely to deliver within the next 7-10 days with a 95% probability.
Reduces/eliminates costs associated with hospital admissions and transportation

Question 8

tocolytic therapy

Answer 8

the attempt to stop or limit uterine contractions in preterm labour using drugs

Question 9

betamimetics

Answer 9

I.V salbutamol, terbutaline, ritodrine are βeta-adrenergic agonists and relax smooth muscle cells in the uterus.

Question 10

side effects of betamimetics

Answer 10

rapid pulse
chest pain
headaches
may delay labour by 48 hrs

Question 11

calcium channel blockers

Answer 11

oral nifedipine reduce muscle contraction by controlling the influx of calcium across the plasma membrane

Question 12

B-agonists

Answer 12

effective in delaying delivery for 48 hours but no effect on perinatal mortality and morbidity

Question 13

indomethacin

Answer 13

effective tocolytic but there are concerns regarding possible fetal and neonatal effects e.g. premature closure of the ductus arteriosus inutero

Question 14

prevention of preterm birth

Answer 14

• Risk factors at booking-in:
  -Previous obstetric history, psychological stress, D&A, STI, ethnicity, economic status, D.V.
  -Social interventions:
• Improve economic and social status, drug counselling, STI awareness.
  -Physical interventions: home uterine monitoring? (bed rest not shown to be effective in reducing preterm birth), U/S cervical assessment should be > 25mm, < 25mm = greater delivery risk in earlier gestations, cervical cerclage, minimising infection, improving nutritional status.

Question 15

diagnosis preterm labour

Answer 15

• Need an awareness of the physiology of labour i.e. term = uterine activity, cervical dilatation and expulsion of the fetus.
• S/S premature labour can be difficult to diagnose and may be non-specific.
• Cervix beginning to efface and dilate on vaginal ultrasound or speculum.
• Treatment often starts on clinical presentation before knowing the state of the cervix on vaginal ultrasound e.g. I.V. antibiotics.

Question 16

treatment issues/contraindications of stopping labour

Answer 16

mature fetus >34 weeks
fetal death
fetal anomaly incompatible with life
SGA/IUGR - unfavourable intrauterine environment
fetal compromise/fetal distress
active haemorrhage
infection/chorioamnionitis (infection occurs when bacteria enter any of the tissues or membranes around a fetus)

Question 17

preterm management

Answer 17

• Tocolysis contraindicated if cervix is dilated.
• Note: accurate gestational age, cervical dilatation (>6cm, transfer is not advised), consider hospital location.
• Careful initial and ongoing assessment: including phone triage, on admission to unit, and during active labour.
• Commence IMI steroids
• Notify NICU/SCN of admission.
• Multidisciplinary team management i.e. notify consultant obstetrician, anaesthetist, neonatologist, O/C paediatrician.
• Room set-up, including respiratory support for neonate.
• Commence on partogram if in established labour.
• Usual labour observations and cares, pain relief: caution with narcotic drugs because of the respiratory suppressant effect upon the preterm neonate, hydration, bladder care, EFM.
• Education, reassurance and support for the woman and partner/family.
• Possible fetal distress, malpresentations, cord involvement.

Question 18

delivery management preterm

Answer 18

rapid second stage
potential fetal distress
active resus
document
debrief

Question 19

medical management preterm

Answer 19

• Arrange transfer to tertiary unit if under 34 weeks.
• Contact NICU for neonatologist consult and parents.
• Conservative management, vaginal delivery or LSCS?
• Arrange U/S and lab studies: LVS, MSU, ?fetal fibronectin, FBC including CRP.
• Prescribe broad spectrum antibiotic course: I.V x 48hrs + 5 days oral course and cycle again if PROM and after cerclage.
• Order tocolytic, steroid course, MgSO4 if

Question 20

midwifery care at ward admission

Answer 20

• Administer I.V fluids, antibiotics, tocolytics and second dose of steroid course.
• Fetal welfare assessment.
• Discuss NSW Premature Outcomes Booklet with parents.
• Explanations and education re: S/S preterm labour and to report same and respond as required. i.e. palpation of contractions, maternal and fetal monitoring and findings, analgesia, notify team, ?repeat speculum/vaginal U/S and documentation of further TPL episodes.
• Gentle ambulation after presenting episode.
• Arrange further information and NICU tour.
• Diversional therapy if hospitalised for an extended period

Question 21

midwifery care at birth

Answer 21

• Prepare room and resus equipment.
• Notify required personnel to be present.
• CTG monitoring.
• Pain relief.
• NVB versus LSCS.
• Episiotomy - Indications?
• Forceps - Indications?
• Delayed cord clamping and length of cord for NICU.

Question 22

premature rupture of membranes

Answer 22

rupture of the amniotic sac prior to 37 weeks completed weeks gestation
1-4% of pregnancies
25% of preterm births

Question 23

PROM pathophysiology

Answer 23

rupture of the membranes occurs when there is focal weakening as a result of extensive changes in collagen metabolism or the intraamniotic pressure is increased

Question 24

PROM maternal and fetal effects

Answer 24

maternal
- 50% will deliver within 1 week.
- Maternal sepsis can be overwhelming.
- Disruption with hospitalisation.
fetal
- Prematurity.
- Fetal infection - chorioamnionitis.
- Fetal compromise: hypoplastic lungs, RDS.
- Developmental abnormalities: contractures.
- Possible offer of TOP

Question 25

PROM diagnosis

Answer 25

• NO VAGINAL EXAMINATION.
• ‘Sterile’ speculum examination.
• Amnicator test in some units.
• Corticosteroids now routinely given with PROM. Earlier concern was that they have the potential to mask the signs of infection.
• Tocolysis is not indicated - associated with increased overall latency, without additional benefits for maternal/neonatal outcomes. For patients with PROM before 34 weeks = increased risk of chorioamnionitis in women who received tocolysis
• Observe for signs of preterm labour

Question 26

PROM management

Answer 26

• In 2016 results of this trial were finally published in the Lancet:
• ‘In the absence of overt signs of infection or fetal compromise, a policy of expectant management with appropriate surveillance of maternal and fetal wellbeing should be followed in pregnant women who present with ruptured membranes close to term’

Question 27

expectant management PROM

Answer 27

• CRP (c-reactive protein) assessment and repeat testing
• Prophylactic antibiotics: I.V and oral course.
• Serial U/S for AFI and fetal growth.
• Rotating oral antibiotics.
• Pad charts and checks

Question 28

multiple pregnancies

Answer 28

-30% of multiple pregnancies end in preterm delivery which may result in increased mortality and severe long term neonatal morbidity. Raynor & Catling (2017)
-Most common pregnancy complication relating to twins is polyhydramnios causing premature labour and prematurity

Question 29

incidence of multiples

Answer 29

• twins/triplets in 2016 was 1.4% of all births.
• Twins:1 in 80 Caucasian pregnancies, with highest rate 1 in 44 West African pregnancies. Lowest rates are seen in Asia.
• Two-thirds of twins are dizygotic and one third are monozygotic
• Twins are more common in women of higher parity and those who are older at conception.
• Dizygotic twinning is also more common in tall women and those who are obese.
• Incidence of triplets: 1 in 6400.
• Incidence of quadruplets: 1 in 512,000

Question 30

twins diagnosis

Answer 30

• Suspected on history and clinical examination:
• History of infertility treatment e.g. ovulation induction.
• Severe hyperemesis.
• ?increased discomforts of pregnancy.
• Other more common obstetric problems – gestational diabetes, pre-eclampsia, large for dates, multiple fetal parts.
• Polyhydramnios may be present in late pregnancy. Confirmation:
• Ultrasound examination is the only reliable method of diagnosing multiple pregnancy

Question 31

multiples general management

Answer 31

• Midwifery- includes antenatal dietary advice and management of S/S.
• Adequate nutrition e.g. eat foods rich in iron and calcium.
• Comfort measures due to uterine distension e.g. use pillows for positional adjustment in bed.
• Not to lie in a supine position to avoid/reduce venocaval compression.
• Medical - includes increased fetal surveillance on U/S, identification of abnormalities, ?prophylactic steroids, MgSO4.

Question 32

multiples - complications

Answer 32

• Anaemia.
• Placenta previa.
• Polyhydramnios and preterm labour = 40% rate with twins.
• Malpresentations: however in 75% of cases Twin 1 presents by the vertex.
• Pre-eclampsia and gestational diabetes.
• PPH
• FGR or intra-uterine death.
• Embryo reduction and selective fetocide?
• Twin-Twin Transfusion Syndrome (small donor twin and large hydropic recipient twin). selective laser photocoagulation of communicating vessels. Best outcomes by a centralised service.

Question 33

monoamniotic twins

Answer 33

are monozygotic, occurs in only 2% of all twins and share amnion, chorion and placenta. Very high perinatal mortality. Require intensive fetal surveillance and EFM.

Question 34

conjoined twins

Answer 34

• Conjoined twins: are monozygotic and occurs when there is extreme late separation of the fetal poles.
• Estimated at 1: 50,000 to 1:100,000 births
• Thoracopagus is the most common form of conjoined twins, with fusion from the anterior thorax to the umbilicus. A common pericardial sac is present in 90% of thoracopagus twins, and conjoined hearts are seen in 75%.

Question 35

antenatal issues for multiples

Answer 35

• Discomforts of pregnancy.
• Polyhydramnios, preterm labour and birth.
• Gestational diabetes.
• Pre-eclampsia.
  Midwifery care:
• Discuss comfort measures.
• Preparation for parenthood.
• Social supports.
• > 28 weeks = increased fatigue and more at risk of polyhydramnios.
• Ensure contact with AMBA pre-delivery.

Question 36

labour care issues for multiples

Answer 36

• Midwife continues to provide labour care.
• Obstetrician, registrar, NNIC and paeds to be aware.
• Room preparation.
• Observations, continuous fetal monitoring.
• Position changes.
• Cannula and analgesia, EDB often inserted.
• Maternal anxiety.
• Third stage management: I.V with 40U Syntocinon.
• Awareness of co-existing condition e.g. pre-eclampsia, diabetes, polyhydramnios and these co-morbidities
• If first twin is cephalic, more likely to have a NVB.
• Maternal birth positions: labour and delivery.
• Medical management, equipment, personnel, skills.
• Close monitoring and delivery of the second twin.
• Anaesthetist and paediatrician x 2 at delivery.
• Anticipate possible neonatal resuscitation e.g. small for dates, preterm, second twin outcome.

Question 37

prep for birth (multiples)

Answer 37

• Double equipment set-up in room e.g. resusc, twin labels.
• Fetal monitoring: usually the first twin by a scalp electrode and the second externally by CTG.
• EDB usually inserted
• Labour is usually straightforward though the higher incidence of malpresentation increases the risk of cord prolapse. VE should be carried out when the membranes rupture.
• Side lying positions for labour if confined to bed.
• Prepare for possible augmentation, vacuum, forceps, LSCS delivery.

Question 38

second stage management (multiples)

Answer 38

• Confirmed by VE.
• Team x 2 present: second midwife, obstetrician, registrar, paeds, anaesthetist.
• Continue FHR monitoring. o Deliver first baby.
• Abdominal palpation/VE to determine second twin presentation.
• Uterine activity.
• Deliver second twin.
• Give oxytocin- usually I.V 40U Syntocinon drip after twin 2 is delivered .
• After twin 1 is born, the cord is clamped and the baby is labeled, and if well the baby can be put to the breast to maintain contractions.
• The lie of the second baby is then confirmed and FHR assessed and monitored continuously. If no fetal distress, descent of the presenting part can be awaited, though the interval should not be prolonged (up to 45 minutes with labour progress), as the second twin is at more risk of asphyxia due to the reduced placental site

Question 39

delivery of second twin

Answer 39

• Occasionally contractions reduce after the first twin and a Syntocinon infusion may be commenced. ARM when the head or breech has descended and delivery proceeds.
• Forceps or ventouse may be applied if fetal distress.
• Active third stage management to commence ONLY after delivery of the second baby. 40 U Syntocinon drip often commenced as PPH more common.
• The placenta and membranes are examined to determine that they are complete and whether the twins are MZ or DZ, and this is confirmed by placental histology.

Question 40

third stage multiples

Answer 40

• CCT, leave cord lengths, double clamp twin 2
• Be aware of risk of uterine atony.
• Continue I.V 40U Syntocinon.
• Check for perineal trauma.
• Examination of placenta, amnions and chorions.
• Check fundus and PV loss.
• Maternal observations

Question 41

potential complications of labour

Answer 41

• Malpresentation of second twin e.g. transverse lie.
• Delay in the birth of the second twin.
• Cord prolapse.
• Locked twins.
• Maternal haemorrhage before birth of second twin.
• PPH.
• Undiagnosed twins