PREMATUREPRELABOUR RUPTURE OF MEMBRANES PROM PRETERM LABOUR POST

PREMATURE/PRELABOUR RUPTURE OF MEMBRANES (PROM), PRETERM LABOUR POST TERM AND IUGR Dr Matthews Anyanwu Lecturer UTG

Introduction Premature/pre-labour rupture of membranes (PROM) at term, is rupture of membranes prior to the onset of labor at or beyond 37 weeks' gestation. Occurs when the bag of water breaks before labour begins. INCIDENCE: 10% of pregnancies PROM could occur before 37 weeks= Preterm PROM (PPROM) 2 - 3% of pregnancies and is not the same as preterm labour However 40 -60% will progress to preterm labour This will lead to prematurity which is the commonest cause of perinatal and neonatal morbidity and mortality Prolonged ROM is any ROM that persists for more than 12 hours and prior to the onset of labor

Pathophysiology At term, programmed cell death and activation of catabolic enzymes, such as collagenase and mechanical forces, result in ruptured membranes. Preterm PROM occurs probably due to the same mechanisms and premature activation of these pathways. However, early PROM also appears to be linked to underlying pathologic processes, most likely due to inflammation and/or infection of the membranes

Aetiology UNKNOWN but the following are known to be associated factors: UTI Low socio-economic status Low BMI Tobacco/smoking cigarette Previous hx of Preterm labour Vaginal bleeding (at any time of pregnancy) Cervical cerclage Amniocentesis Polyhydramnios Multiple pregnancy Malpresentation Familial hx of PROM Collagen deficiency Primigravida

Clinical Presentation Leakage of fluid, per vaginam Vaginal bleeding, and Pelvic pressure, but no contractions. Fever Flank pain Reduce size of uterus Maternal or fetal tachycardia Uterine tenderness Leucocytosis

DIAGNOSIS Digital cervical examination is NOT indicated in PROM. Sterile speculum vaginal examination of the cervix and vaginal Pooling of fluid in the posterior vaginal fornix or leakage of fluid from the cervix, Ferning – fluid is air-dried on a slide, amniotic fluid will form fern-like pattern of crystallization due to NACL. Nitrazine test – sterile cotton-tipped swab should be used to collect fluid, amniotic fluid will turn blue showing alkaline p. H (7. 0 -7. 25). These are the hallmarks of PROM!

Differential diagnosis Alkaline p. H on Nitrazine paper can also be cause by: Vaginal infections, Presence of blood or semen in sample. Cervical mucus can cause ferning but usu. Less extensive than that with PROM. Pooling of fluid is by far the most accurate for diagnosis of ROM. If all fluid has leaked out as in early PROM, an ultrasonographic examination may then show absence of or very low amounts of amniotic fluid in the uterine cavity.

Investigations FBC with differential Urinalysis Urine culture and sensitivity HVS and endocervical swab for microscopy, gram stain, culture and sensitivity Ultrasound Amniotic fluid index Amniocentesis for culture and sensitivity

Complications of PROM Preterm labour Prolapse of cord Placenta abruption Chorioamnionitis Infections of the newborn Puerperal infection (endometritis)

Assessment/Identification of Problem Obtain last menstrual period (LMP) and expected date of delivery; -Ask the patient when the membranes ruptured; - Ask for the colour and odour of the liquor; -Inspect the vagina and take note of colour and odour of liquor ; -Perform a speculum examination (using sterile instrument); -Check if cord is prolapsed, and pulsating; -Check for vital signs (temperature, pulse rate, respiratory rate, BP); -Check the abdomen for uterine contractions; -Perform an abdominal palpation noting the fundal height, presentation and lie of the fetus; -Check the fetal heart sounds

Treatment Most patients (80%) enter spontaneous labor within 24 hours if at term. If membranes have been ruptured for more than 12 hours: - check and record the fetal heart rate - apply clean sanitary pad - give broad spectrum antibiotics e. g. Ampicillin or Ampiclox, 500 mg 6 hourly x 5 days. Erythromycin 250 mg 6 hrly for 10 days in PPROM is the drug of choice if conservative management is indicated. - check and record vital signs (temperature, pulse rate, respiratory rate and BP) If there are no signs of infection and pregnancy is less than 34 weeks; - admit the patient and manage expectantly Give corticosteroids and tocolytics as appropriate;

Treatment If there are no signs of infection and pregnancy is 37 weeks or more give prophylactic Ampicillin or Ampiclox, 500 mg 6 hourly for 7 days; Assess the cervix: - if favourable (soft, thin, partly dilated) induce labour using induction protocol - if unfavourable (firm, thick, closed), take appropriate action according to the protocol on ripening of the cervix

CHORIOAMNIONITIS If chorioamnonitis is present, patient should be actively delivered regardless of GA. Induce labour if patient is not in labour If delivery- induction interval would be long; deliver by C/S avoid regional anaesthesia Ensure combination of broad spectrum antibiotics

ANTIBIOTICS Multiple trials have examined the advantages and disadvantages of using antibiotics and the choice of antibiotics. In most studies, use of antibiotics has been associated with prolongation of pregnancy and reduction in infant and maternal morbidity

CORTICOSTERIODS The use of corticosteroids to accelerate lung maturity should be considered in all patients with PPROM (24 -34 weeks' gestation) Data indicate that the use of corticosteroids reduces neonatal morbidity and mortality. The rates of respiratory distress syndrome (RDS), necrotizing enterocolitis, and intraventricular hemorrhage were all lower When either 12 mg of betamethasone IM was given twice in a 24 -hour interval or dexamethasone 6 mg 6 hrly was given for 4 doses.

CORTICOSTERIODS. . A single rescue course of antenatal corticosteroids may be considered if the antecedent treatment was given more than 2 weeks When the gestational age is less than 32 weeks, and the woman is judged by the clinician to be likely to give birth within the next week. However, regularly scheduled repeat courses or more than 2 courses are not recommended. Further research regarding the risks and benefits, optimal dose, and timing of a single rescue course of steroid treatment is still awaited.

TOCOLYSIS The most common cause of labor in the setting of PPROM is underlying chorioamnionitis. Therefore, tocolytics are contraindicated in established case of chorionamnionitis The only indication for tocolysis in PPROM is to gain 48 hours to allow completion of steroid course and in-utero-transfer were indicated.

PRETERM LABOUR

Definition Preterm labor is defined as the presence of uterine contractions of sufficient frequency and intensity to effect progressive effacement and dilation of the cervix prior to term gestation (between 28 and 37 wk). Preterm labor precedes almost half of preterm births and preterm birth occurs in approximately 12% of pregnancies and is the leading cause of neonatal mortality

Causes Iatrogenic as in wrong dating during termination of pregnancy Infections Over-distension of the uetrine cavity Vascular Intercurrent illness Cervical weakness Stress(physiology or physical) Idiopathic

Non- modifiable Risk Factors PROM Last birth preterm: 20% risk Last two birth preterm: 40% risk Twin pregnancy: 50% risk Uterine abnormalities

other predisposing factors Congenital anomalies Cervical damage(cone biopsy, repeated dilatation) Fibriods Factors in current pregnancy -Recurrent antepartum haemorrhage -Intercurrent illness(Pulmonary diseases, Renal diseases, Heart diseases, Severe anaemia) -Any surgery(Any intra-abdominal procedure, Conization of the cervix, Previous incision of the cervix or uterus, )

Minor non modifiable Teenagers having second or subsequent babies Parity (=0 or >5) Ethnicity (black race) Poor socio-economic status Education

Modifiable risk factors Smoking Drug abuse BMI<20 Inter pregnancy interval of <1 yr

Clinical Presentation - Regular or frequent contractions or tightening of the uterus - Change in type or amount of vaginal discharge. - Pelvic or lower abdominal pressure or pain - Constant, low dull backache - Ruptured membranes (broken bag of water)

Investigations Complete blood count Urinalysis, urine culture and sensitivity Ultrasound Amniocentesis Cervical cultures C- reactive protein Fetal fibronectin enzyme Cervical length examination

Mgtx Tocolytic agents, while generally safe in appropriate dosages with proper clinical monitoring, have potential morbidity and should only be used after consideration of the risks and benefits of such use. Neonatal morbidity and mortality are greatly affected by gestational age, especially when the pregnancy is less than 28 weeks’ gestation

mgt On the other hand, the risk of neonatal mortality and morbidity is low after 34 completed weeks of gestation; although a trial of acute tocolysis may be initiated, aggressive tocolytic therapy is generally not recommended beyond 34 weeks, due to potential maternal complications. Between 24 and 33 weeks’ gestation, benefits of tocolytic therapy are generally accepted to outweigh the risk of maternal and/or fetal complications and these agents should be initiated provided no contraindications.

mgt The primary purpose of tocolytic therapy today is to delay delivery for 48 hours to allow the maximum benefit of glucocorticoids to decrease the incidence of RDS. Corticosteroid therapy, between 24 and 34 weeks of gestation, is currently the only therapy shown to improve fetal survival: Betamethasone, 12 mg, im once dly for two days, or dexamethasone, 6 mg, im 6 hrly for 4 doses. Most obstetricians are still very comfortable with 12 mg 2 doses 12 hours apart.

DRUGS(tocolytics) - Salbutamol -Ritodrine - Terbutaline - Indomethacine - Nifedipine - Atosiban - Magnesium sulphate - Alcohol

mgt Criteria that indicate consideration of tocolytic therapy include more than 6 contractions per hour resulting in a demonstrated cervical change or presumed prior cervical change (transvaginal cervical length < 2. 5 cm, >50% cervical effacement, or cervical dilation ≥ 2 cm). If contractions are present without cervical change, management options include continued observation or therapeutic sleep (eg, morphine sulphate 10 -15 mg subcutaneous). If the FFN is negative and the contractions abate, the patient may be sent home with appropriate follow-up evaluation.

mgt The most common tocolytic agents used for the treatment of preterm labor are nifedipine, Atosiba , magnesium sulfate (Mg. SO 4), indomethacin. In the past, beta-mimetic agents, such as terbutaline or ritodrine, were the agents of choice, But in recent years their use has been significantly curtailed due to maternal and fetal side effects, such as maternal tachycardia, hyperglycemia, and palpitations.

mgt The use of these agents can lead to pulmonary edema, myocardial ischemia, and cardiac arrhythmia. Mg. SO 4 is associated with more maternal toxicity, indomethacin is associated with more fetal and neonatal toxicity.

MGSO 4 Magnesium sulfate is widely used as the primary tocolytic agent because it has similar efficacy to terbutaline with far better tolerance. Maternal side effects: flushing, nausea, headache, drowsiness, and blurred vision. The mother should be monitored for toxic effects, such as respiratory depression or even cardiac arrest, that can occur at supratherapeutic levels. In addition, magnesium sulfate readily crosses the placenta and may lead to respiratory and motor depression of the neonate. The use of magnesium sulfate usually requires baseline maternal laboratory evaluation, including CBC count and serum creatinine level, urine output greater than 30 m. L/h, normal vital signs, and appropriate maternal mentation. .

Cont… The initial recommended loading dose is 4 -6 g IV over 20 minutes, followed by a maintenance dose of 1 -4 g/h depending on urine output and persistence of uterine contractions When acute mild toxicity exists in the presence of normal urine output, magnesium sulfate should be temporarily discontinued until the serum magnesium level return to normal. If the toxicity symptoms are life threatening, administering 1 g of calcium gluconate by slow intravenous push and strongly considering not reinstituting magnesium sulfate despite the return to normal levels is recommended.

Indomethacin is an appropriate first-line tocolytic for the pregnant patient in early preterm labor (< 30 wk) or preterm labor associated with polyhydramnios. During treatment, urine output, maternal temperature, and amniotic fluid index (AFI) should be evaluated periodically. The initial recommended dose is 100 mg PR followed by 50 mg PO every 6 hours for 8 doses. If oligohydramnios occurs, the amniotic fluid usually reaccumulates when the indomethacin is stopped, but persistent fetal anuria, renal microcystic lesions, and neonatal death have been reported. Indomethacin can also cause premature closure or constriction of the ductus arteriosus. Since this effect is more common after 32 weeks' gestation, indomethacin therapy is not usually recommended after 32 weeks.

Nifedipine Several randomized studies have shown that the use of nifedipine in comparison with other tocolytics is associated with a more frequent successful prolongation of pregnancy, resulting in significantly fewer admissions of newborns to the neonatal intensive care unit, and may be associated with a lower incidence of RDS, necrotizing enterocolitis, and intraventricular hemorrhage. A recommended initial dosage of nifedipine is 20 mg orally, followed by 20 mg orally after 30 minutes. If contractions persist, therapy can be continued with 20 mg orally every 3 -8 hours for 48 -72 hours with a maximum dose of 160 mg/d. After 72 hours, if maintenance is still required, long-acting nifedipine 30 -60 mg daily can be used.

Nifedipine Contraindications of nifedipine therapy include allergy to nifedipine, hypotension, hepatic dysfunction, concurrent use of beta-mimetics or Mg. SO 4, transdermal nitrates, or other antihypertensive medication. Side effects: maternal tachycardia, palpitations, flushing, headaches, dizziness, and nausea. Continuous monitoring of the fetal heart rate is recommended as long as the patient has contractions; the patient's pulse and blood pressure should be carefully monitored.

Prevention The most important is proper Antenatal care where risk factors will be identified and properly mgtx Intercurrent illnesses tx Health Education

Post term Pregnancy beyond 42 completed gestational weeks Management is delivery by the safest route to mother and baby Fetal surveillance beyond 42 weeks do not add any value rather placental insufficency will ensue Perinatal mortality increase 2 -fold and 4 -fold at above 42 and 43 weeks respectively

Post term Meconium stained liquor increased by 40%. Risk meconium aspiration is common with associated poor neonatal outcome Known methods of induction of labour may be associated with increased complications Therefore prevention of post term pregnancy is by routine early pregnancy dating scan.

IUGR Small–for–gestational age (SGA) refers to an infant born with a birth weight less than the 10 th centile. Historically SGA birth has been defined using population centiles. But, the use of centiles customised for maternal characteristics (maternal height, weight, parity and ethnic group) as well as gestational age at delivery and infant sex, identifies small babies at higher risk of morbidity and mortality than those identified by population centiles.

Fetal growth restriction (FGR) is not synonymous with SGA. Some, but not all, growth restricted fetuses/infants are SGA while 50– 70% of SGA fetuses are constitutionally small, with fetal growth appropriate for maternal size and ethnicity

Clinical examination Abdominal palpation has limited accuracy for the prediction of a SGA neonate and thus should not be routinely performed in this context. Serial measurement of symphysis fundal height (SFH) is recommended at each antenatal appointment from 24 weeks of pregnancy as this improves prediction of a SGA neonate.

Women with a single SFH which plots below the 10 th centile or serial measurements which demonstrate slow or static growth by crossing centiles should be referred for ultrasound measurement of fetal size. Women in whom measurement of SFH is inaccurate (for example: BMI > 35, large fibroids, hydramnios) should be referred for serial assessment of fetal size using ultrasound.

Fetal abdominal circumference (AC) or estimated fetal weight (EFW) < 10 th centile can be used to diagnose a SGA fetus. Where the fetal AC or EFW is < 10 th centile or there is evidence of reduced growth velocity, women should be offered serial assessment of fetal size and umbilical artery Doppler

INVESTIGATIONS Offer a referral for a detailed fetal anatomical survey and uterine artery Doppler by a fetal medicine specialist if severe SGA is identified at the 18– 20 week scan. Karyotyping should be offered in severely SGA fetuses with structural anomalies and in those detected before 23 weeks of gestation, especially if uterine artery Doppler is normal.

Serological screening for congenital cytomegalovirus (CMV) and toxoplasmosis infection should be offered in severe SGA. Testing for syphilis and malaria should be considered in high risk populations. Uterine artery Doppler has limited accuracy to predict adverse outcome in SGA fetuses diagnosed during the third trimester.

DELIVERY In the preterm SGA fetus with umbilical artery AREDV detected prior to 32 weeks of gestation, delivery is recommended when DV Doppler becomes abnormal or UV pulsations appear, provided the fetus is considered viable and after completion of steroids. Even when venous Doppler is normal, delivery is recommended by 32 weeks of gestation and should be considered between 30– 32 weeks of gestation. .

If MCA Doppler is abnormal, delivery should be recommended no later than 37 weeks of gestation. In the SGA fetus detected after 32 weeks of gestation with an abnormal umbilical artery Doppler, delivery no later than 37 weeks of gestation is recommended. In the SGA fetus detected after 32 weeks of gestation with normal umbilical artery Doppler, a senior obstetrician should be involved in determining the timing and mode of birth of these pregnancies. Delivery should be offered at 37 weeks of gestation

HOW TO DELIVER In the SGA fetus with umbilical artery AREDV delivery by caesarean section is recommended. In the SGA fetus with normal umbilical artery Doppler or with abnormal umbilical artery PI but end –diastolic velocities present, induction of labour can be offered but rates of emergency caesarean section are increased and continuous fetal heart rate monitoring is recommended from the onset of uterine contractions. Early admission is recommended in women in spontaneous labour with a SGA fetus in order to instigate continuous fetal heart rate monitoring.

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