MANAGEMENT OF PRETERM LABOR WITH INTACT MEMBRANES

by Dr. Elmizadeh

Women with signs and symptoms of preterm labor with intact membranes are managed much the same as described above for those with preterm ruptured membranes. If possible, delivery before 34 weeks is delayed.

Amniocentesis to Detect Infection

A. elevated leukocyte count

B. low glucose level

C. high IL-6 concentration

D. positive Gram stain result

amniocentesis to diagnose infection does not improve pregnancy outcomes in women with or without membrane rupture .

The American College of Obstetricians and Gynecologists has concluded that there is no evidence to support routine amniocentesis to identify infection.

Corticosteroids for Fetal Lung Maturation

Corticosteroid therapy was effective in lowering the incidence of respiratory distress syndrome and neonatal mortality rates if birth was delayed for at least 24 hours after initiation of betamethasone.Data were insufficient to assess corticosteroid effectiveness in pregnancies complicated by hypertension, diabetes, multifetal gestation, fetal-growth restriction, and fetal hydrops. However, that it was reasonable to administer corticosteroids in women with these complications.

The issue of the fetal and neonatal safety with single versus repeat courses of intramuscular corticosteroids for lung maturation?? some experimental evidence supports the view that adverse corticosteroid effects are dose dependent.

“Rescue Therapy” This refers to administration of a repeated corticosteroid dose when delivery becomes imminent and more than 7 days have elapsed since the initial dose.

The American College of Obstetricians and Gynecologists (2012a) has taken the position that a single rescue course of antenatal corticosteroids should be considered in women before 34 weeks whose prior course was administered at least 7 days previously.

Antimicrobials Antimicrobials have been given in an attempt to arrest preterm labor. Results have been disappointing.

Antimicrobial treatment of women with preterm labor for the sole purpose of preventing delivery is generally not recommended.

In a follow-up of the ORACLE II trial, Kenyon and associates (2008b) reported that fetal exposure to antimicrobials in this clinical setting was associated with an increased cerebral palsy rate at age 7 years compared with that of children without fetal exposure.

Bed Rest This is one of the most often prescribed interventions during pregnancy, yet one of the least studied.

There is insufficient evidence to support the use of bed rest and there are several studies showing harm with its use.

Cervical Pessaries

There is increasing interest in the use of cervical pessaries to prevent preterm birth. Silicone rings, also know as the Arabin pessary, are being used to support the cervix in women with a sonographically short cervix. For 385 Spanish women with cervical lengths ≤ 25 mm, Goya and colleagues (2012) provided a silicone pessary or expectant management. There was spontaneous delivery before 34 weeks’ gestation in 6 percent of women in the pessary group compared with 27 percent in the expectant management group. Hui and associates (2013) randomly assigned approximately 100 women with cervices < 25 mm at 20 to 24 weeks to silicone pessaries or expectant management. The prophylactic use of silicone pessary did not reduce the rate of delivery before 34 weeks. These two studies with conflicting results are the only randomized trials to date.

Emergency or Rescue Cerclage

Magnesium Sulphate for Neuroprotection

“Imminent preterm birth” is defined as a highlikelihood of birth due to one or both of thefollowing conditions :• Active labour with ≥ 4 cm of cervical dilation,with or without PPROM.• Planned preterm birth for fetal or maternalindications

Recommendation

1. For women with imminent preterm birth(≤ 31+6 weeks), antenatal magnesium sulphateadministration should be considered for fetalneuroprotection. (I-A)2. Although there is controversy about uppergestational age, antenatal magnesium sulphate forfetal neuroprotection should be considered fromviability to ≤ 31+6 weeks. (II-1B)3. If antenatal magnesium sulphate has been startedfor fetal neuroprotection, tocolysis should bediscontinued. (III-A)

4. Magnesium sulphate should be discontinued ifdelivery is no longer imminent or a maximum of 24hours of therapy has been administered. (II-2B)5. For women with imminent preterm birth, antenatalmagnesium sulphate for fetal neuroprotectionshould be administered as a 4g IV loading dose,over 30 minutes, followed by a 1g/hr maintenanceinfusion until birth. (II-2B)6. For planned preterm birth for fetal or maternalindications, magnesium sulphate should be started,ideally within 4 hours before birth, as a 4g IVloading dose, over 30 minutes, followed by a 1g/hrmaintenance infusion until birth. (II-2B)

7. There is insufficient evidence that a repeatcourse of antenatal magnesium sulphate for fetalneuroprotection should be administered. (III-L)8. Delivery should not be delayed in order toadminister antenatal magnesium sulphate for fetalneuroprotection if there are maternal and/or fetalindications for emergency delivery. (III-E)9. When magnesium sulphate is given for fetalneuroprotection, maternity care providers shoulduse existing protocols to monitor women who arereceiving magnesium sulphate for preeclampsia/eclampsia. (III-A)

The following recommendations and conclusions are based on good and consistent scientific evidence (Level A):•A single course of corticosteroids is recommended for pregnant women between 24 weeks of gestation and 34 weeks of gestation who are at risk of preterm delivery within 7 days. •Accumulated available evidence suggests that magnesium sulfate reduces the severity and risk of cerebral palsy in surviving infants if administered when birth is anticipated before 32 weeks of gestation•The evidence supports the use of first-line tocolytic treatment with beta-adrenergic agonist therapy, calcium channel blockers, or non-steroidal anti-inflammatory drugs (NSAIDs) for short-term prolongation of pregnancy (up to 48 hours) to allow for the administration of antenatal steroids. •Maintenance therapy with tocolytics is ineffective for preventing preterm birth and improving neonatal outcomes and is not recommended for this purpose. •Antibiotics should not be used to prolong gestation or improve neonatal outcomes in women with pre-term labor and intact membranes.

The following recommendations and conclusions are based on limited or inconsistent scientific evidence (Level B):•A single course of repeat antenatal corticosteroids should be considered in women whose prior course of antenatal corticosteroids was administered at least 7 days previously and who remain at risk of preterm birth before 34 weeks of gestation. •Bed rest and hydration have not been shown to be effective for the prevention of preterm birth and should not be routinely recommended. .

Thanks for your attention