postdate pregnancy
TRANSCRIPT
ABOUBAKR ELNASHAR
Postterm pregnancy: pregnancies that last longer
than 42 weeks.
Postdate pregnancies: pregnancies that last longer
than the estimated date of confinement, (ie, 40 wk).
ABOUBAKR ELNASHAR
ABOUBAKR ELNASHAR
At 40 w only 58% had delivered.
By 41 w: 74%
By 42 w: 82%.
Postterm pregnancy(>42W):
16%. (12%)
Pregnancies >41: 26%
Postdate pregnancy >40W:42% (NICE)
ABOUBAKR ELNASHAR
ABOUBAKR ELNASHAR
Both postterm and postdate pregnancy is inaccurate dating criteria. Ultrasound dating is inaccurate for a patient who presents late in pregnancy An ultrasound before 20 w reduces the need for induction for post term pregnancy (NICE,A)
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CRL: ±3-5 days, ultrasound at 12-20 w:±1 week, at 20-30 weeks:±2 w after 30 weeks: ±3 w.
ABOUBAKR ELNASHAR
ABOUBAKR ELNASHAR
ABOUBAKR ELNASHAR
• In high risk pregnancy • nonreassuring surveillance, • oligohydramnios, • growth restriction, • certain maternal diseases, The risks of remaining pregnant
outweigh the risks of delivery
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Diabetes in pregnancy fivefold increase in perinatal mortality rate: induction of labour prior to their estimated date for delivery. (NICE C)
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Elective induction of labor at or after 39 W in the absence of documented lung maturity provided that 1. 36 w after a positive hCG test 2. 20 w after fetal heart tones have been established by a fetoscope or 3. 30 w by a Doppler examination, or 4. 39 w’ have been established by a CRL or 5. by an ultrasound performed before 20 w consistent with dates by the LMP.
ABOUBAKR ELNASHAR
B. In the low-risk pregnancy. •The certainty of gestational age, •cervical examination findings, •estimated fetal weight, and •past obstetrical history •Involving the patient in this discussion
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Inducing labor at 41 weeks’ gestation in an accurately dated, low-risk pregnancy, regardless of cervical examination findings. 1. Averts the need for antepartum fetal surveillance and
2. does not increase the cesarean delivery rate; in fact, it may decrease the cesarean delivery rate.
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3. Perinatal morbidity and mortality do not increase appreciably between 40-41 weeks of gestation; 4. Several complications are associated with postterm pregnanciesa.
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a.macrosomia, shoulder dystocia, and
cephalopelvic disproportion b.perinatal mortality increases c.risk of stillbirth increases from 1 per 3000 ongoing pregnancies at 37
weeks to 3 per 3000 ongoing pregnancies at 42
weeks to 6 per 3000 ongoing pregnancies at 43
weeks.
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5. increasing the risk for cesarean delivery with a failed induction is far less likely in the era of safe and effective cervical ripening agents.
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#A meta-analysis by Grant reviewed 11 trials and concluded that a policy of routine induction had a lower rate of perinatal morbidity and cesarean delivery, demonstrating both fetal and maternal benefit compared to expectant management.
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#A recent review in the Cochrane Library concluded that routine induction in low-risk pregnancies at or after 41 weeks’ gestation is associated with a reduction in perinatal mortality, with no increase in the rate of instrument deliveries or cesarean delivery.
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In summary, routine induction at 41 weeks’ gestation does not increase the cesarean delivery rate, and may decrease it, without negatively affecting perinatal morbidity or mortality. In fact, there may be both maternal and neonatal benefits to a policy of routine induction of labor in well-dated low-risk pregnancies at 41 weeks’ gestation.
ABOUBAKR ELNASHAR
A policy of induction of labour prior to 41 weeks would generate an increase in workload without reducing perinatal mortality (NICE).
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•>42 wk : should be used
•before 41 weeks: not used, not improve
outcome
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From 42 weeks women who decline induction of labour should be offered increased antenatal monitoring consisting of a twice weekly CTG and ultrasound estimation of maximum amniotic pool depth. (NICE A)
A modified biophysical profile consisting of a nonstress test and an amniotic fluid index have been shown to be as sensitive as a full biophysical profile.
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1.An amniotic fluid index of more than 8
cm and 2. a reactive fetal heart rate tracing are
reassuring.
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3. If the tracing remains nonreactive, a. A contraction stress test or b. a full biophysical profile. These may also
be used if the tracing is reactive but shows fetal heart rate decelerations.
However, in the pregnancy that is beyond 41 weeks of gestation, the threshold for
delivery should be very low.
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In summary, the use of a nonstress test and an amniotic fluid index 2 times per week for postterm, not postdate, pregnancies may decrease fetal mortality. In addition, if any indication during antepartum surveillance leads the practitioner to question the intrauterine environment, delivery should be the rule.
ABOUBAKR ELNASHAR
ABOUBAKR ELNASHAR
Once the decision to deliver a patient has been made, the route of delivery and the specifics of intrapartum management depend on individual circumstances,
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Where?
Risk factors (e.g.suspected fetal growth compromise, previous caesarean section and high parity): C The induction process should not occur on an antenatal ward.
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HOW?
80% of patients who reach 42 weeks’ gestation have an unfavorable cervical examination finding (ie, Bishop score <7) (Harris, 1983).
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A.chemical 1. prostaglandin E1 tablets for oral or
vaginal use, 2. prostaglandin E2 gel for intracervical
application, and 3. a vaginal insert containing 10 mg of
dinoprostone.
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Oxytocin compared to prostaglandins for induction of labour Prostaglandins should be used in preference to using oxytocin when induction of labour is undertaken in either nulliparous or multiparous women with intact membranes regardless of their cervical favourability.A Either prostaglandins or oxytocin may be used when induction of labour is undertaken in nulliparous or multiparous women who have ruptured membranes, regardless of cervical status,as they are equally effective. A
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Comparison of different regimens of oxytocin administration Oxytocin should not be started for 6 hours following administration of vaginal prostaglandins. C In women with intact membranes amniotomy should be performed where feasible prior to commencement of an infusion of oxytocin. C
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B. mechanical. 1. Membrane sweeping or stripping 2. Foley balloon catheters placed in the cervix (Sullivan, 1996),
3. extra-amniotic saline infusions, and 4. laminaria: effective (Guinn, 2000).
ABOUBAKR ELNASHAR
. Membrane sweeping Prior to formal induction of labour, women should be offered sweeping of the membranes. A -is not associated with an increase in maternal or neonatal infection. -is associated with increased levels of discomfort during the procedure and bleeding.
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EFM
Management of complications
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Intrapartum fetal monitoring: EFM If the fetal heart rate tracing is equivocal, a. fetal scalp stimulation, b. fetal scalp blood sampling, and/or c. fetal pulse oximetry d. If the practitioner cannot find reassurance that the fetus is tolerating labor, cesarean delivery is recommended.
ABOUBAKR ELNASHAR
•Management of complications presence of meconium, macrosomia, and fetal intolerance to labor.
ABOUBAKR ELNASHAR
A.meconium. {increased uteroplacental insufficiency,
which leads to hypoxia in labor and activation of the vagal system}.
1. amnioinfusion of isotonic sodium chloride solution and 2. suctioning of the oropharynx and nose upon delivery of the head
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B. Fetal macrosomia can lead to maternal and
fetal birth trauma and to arrest of both first- and second-stage labor. Recognizing the limitations of ultrasound at term, it is still advisable to obtain
1.an estimated fetal weight prior to induction of the postdate pregnancy.
2. mid-pelvic instrument deliveries should not be attempted.
3. delivery plan is being prepared for shoulder dystocia
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C. uterine hypercontractility with a suspicious or pathological cardiotocograph (CTG), secondary to oxytocin infusions, 1. the oxytocin infusion should be decreased or discontinued.B 2. In the presence of abnormal FHR patterns and uterine hypercontractility (not secondary to oxytocin infusion) tocolysis should be considered. A suggested regime is subcutaneous terbutaline 0.25 milligrams. A
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D. suspected or confirmed acute fetal compromise, delivery should be accomplished as soon as possible, taking account of the severity of the FHR abnormality and relevant maternal factors. The accepted standard has been that ideally this should be accomplished within 30 minutes. B
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