J Obstet Gynecol Ind Vol. 54, No.5 ; September/October 2004 Pg 460-463

Evaluation of Transabdominal Amnioinfusion in the AntepartumManagement of Oligohydramnios Complicating Preterm Pregnancies.

R Gowri, S SoundararaghavanDepartment of Obstetrics and Gynecology, Jawaharlal Inst itute of Post-graduate Medical Education and Research (fIPMER),Pondicherry - 605006.

OBJECTIVES - To assess the role of antepartum amnioinfusion in raising the amniotic fluid index andprolonging the pregnancy, and its effect on perinatal outcome in cases with pre term oligohydramnios.METHODS - Seventeen singleton pregnancies from 24 to 34 weeks of gestation with amniotic fluid index ofS5, were randomly allocated to two groups controls (nine women) and subjects (eight women). Transabdominalamnioinfusion was performed in subjects under ultrasonic guidance and repeated weekly till deliver y ifoligohydramnios recurred or persisted. Comparison was made with Chi-Square and t-test. RESULTS ­Am nioinfu sion succeeded in five of the eight subjects. A total of eigh t successful amnioinfusions w er eperformed. Th e rise in amniotic fluid index of 3.67 em was significantly higher in the subjects compar ed tocontrols (p<O.01). The perinatal outcome was generally poor with only five out of 17 babies surviving . Therewere no maternal complications. CONCLUSIONS - Transabdominal amnioinfusion is a safe procedure. Itsignificantly raises the amniotic fluid index. However perinatal outcome remains poor.

Key words: amnioinfusion, oligohydramnios

Introduction

Oligohydramnios poses a challenge for the obstetrician.The etiology could be fetal urinary obstruction, absenceof fetal renal function, preterm premature rupture ofmembranes (PPROM) or growth restriction of the fetus.Whatever the underlying cause, the prognosis remainspoor especially if oligohydramnios is severe or noted insecond trimester. Physiological fetal growth and fetallung development require a critical volume of amnioticfluid. Theoretically, the absence or inadequacy ofamniotic flu id allows the uterus to exert continuouspressure against the fetus resulting in abnormal fetalgrowth . The duration and severity of oligohydramniosare important events in predicting the rate of pulmonaryhypoplasia and neonatal morbidity". There are noeffective ways to treat oligohydramnios other than bedrest and hydration.Transabdominal amnioinfusion hasrecently come up as an alternative treatment. This studyw as undertaken to evaluate the role of antepartumtransabdominal amnioinfusion in preterm pregnanciescomplicated by oligohydramnios.

Material and Methods

This randomized control study was undertaken over aperiod of 10 months from April 2000, after obtaining

Paper received on 29/03/04 ; accepted on 03/05/04

Correspondence :Dr. Gowri DorairajanTyp e V/ 4, Dhanvantari Nagar, JIPMER,Pondicherry 605 006. IndiaTel. 0431 2272804 Email : gowridoral@sify.com

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clearance from the ethical committee of the institution.

Inclusion criteria were singleton pregnancies w itholigohydramnios [Amniotic fluid index (AFI) <5] at 24to 34 weeks of pregnancy. Exclusion criteria were offrank chorioamnionitis, preterm labor and placentalabruption.

Seventeen women who consented to participate in thestudy were randomly allocated to the control group(expectant management) and study group (managementby amnioinfusion) by sealed envelope method.

Procedure of amnioinfusion

A preliminary baseline scan was performed. Writteninformed consent was obtained.Injection ampicillin 19m.was given intravenously to all the women after test dose.Under sonography control and with aseptic precautionsa 20-gauge needle was introduced transabdominally inthe amniotic cavity after local infiltration, and 150-350mL of warmed isotonic saline was infused at a rate of 25­30 mL / min. This was repeated at weekly interval tilldelivery if oligohydramnios recurred or persisted. Onecourse of steroids 6 mg dexamethasone intranuscutarly6 hourly for 4 doses was given to all wome n at theoutset. Oral ampicillin 500/ mg was given 6 hourly for 7days to all women with ruptured membranes.

The control group was expectantly managed after apreliminary scan, with plenty of oral fluids and bed rest.

Repeat scans were performed to note the AFI, 48 hoursafter admission / ammio infusion and weekly thereafter.

The following outcome parameters were recorded:

1. Amniotic fluid index (AFI) before and after theprocedure or admission.

2. Time interval between PPROM and delivery (Latencyperiod).

3. Abnormal fetal heart patterns.

4. Mode of delivery.

5. Perinatal morbidity and mortality.

6. Clinical evidence of postpartum endometritis.

The data collected were tabulated and compared usingthe SPSS package with student t test and Chi-squaretests .

Results

Amnioinfusion succeeded in five women. A total of eightsuccessful amnioinfusions were performed in them (donetwice in three women). The baseline AFI, period ofgestation, PPROM and birth weights are shown in TableI. These parameters were comparable in the two groups.Table II shows the mean rise in AFI, median latencyperiod of pregnancy, abnormal fetal heart rate patterns,number of stillbirths and neonatal deaths. The meanincrease in AFI was significantly higher (p=0.0146) inthe successful subjects. None of the babies born alivehad pulmonary hypoplasia. Almost all the babies bornalive, but for one each in the two groups, neededadmission to the neonatal intensive care unit.Respiratory distress and sepsis were the commonestproblems. One of the still born babies diagnosed as acase of renal agenesis after amnioinfusion, had skeletalabnormality.

There was one intrauterine death in the study group.The woman was a second gravida with 32 weekspregnancy with transverse lie and PPROM. Successfulamnioinfusion was done but the fetus died in-utero after48 hours. She underwent cesarean section as attemptedversion after repeat successful amnioinfusion failed anddelivered a 1200 gm dead fetus. There was no evidenceof cord hematoma or of placental or cord accident. Threeout of the six PPROM cases in the study group and twoout of the seven PPROM cases in the control group wentinto labor within 24 hours of amnioinfusion I admissionindicating that the procedure did not increase the risk ofpreterm labor. Only two of the 17 women were delive~ed

by cesarean section. The second woman needmgcesarean section belonged to the control group. She hadoligohydramnios due to growth restriction and hadintrapartum abnormal fetal heart rate pattern. Overall,only five babies survived one in the successfulamnioinfusion group and two each in the control andfailed amnioinfusion group. Amnioinfusion helped to

Evaluation of Transabdominal Amnioinfueion

diagnose renal agenesis in one case. There were nomaternal complications in the form of clinical evidenceof endometritis.

Discussion

Transabdominal amnioinfusion to manage secondtrimester oligohydramnios is a new method. Only fewstudies are available in the literature . There havebeen no randomized control trials. Fisk et aF carriedout therapeutic antenatal transabdominalamnioinfusion in women of oligohydramnios due tovarious causes over a period of 4 Vz years. They did92 antenatal amnioinfusions in 61 pregnant womenwith a success rate of 95%. They found an increasein the latency period and reduction in pulmonaryhypoplasia in the infused group. However they alsohad a poor perinatal survival with only 12 of the 61(5.08%) babies going home. 2.2% of their cases werecomplicated by clinical chorioamnionitis.

Sarno et al- evaluated transabdominal amnioinfusionin women with fetal growth restriction andoligohydramnios, and observed reversal of chronichypoxemia and stabilization of amniotic fluid volumein at least one of the four women studied.

Garzetti et a14 performed amnioinfusions in PPROMcases only over 1 Vz years They studied 18 cases and 18controls with mean gestation of 25 weeks anddemonstrated a significant prolongation of pregnancyand improvement in the fetal heart rate short termvariability in the nonstress test in the amnioinfusedgroup of cases. But they did not comment on the perinataloutcome.

Locatelli et a15 evaluated amnioinfusion in 36 PPROMcases with mean gestaton of 19.2 weeks over a 7 Vz yearperiod . They found a considerable reduction inpulmonary hypoplasia and neurological sequelae. Theyobserved that the cases in whom amnioinfusionalleviated oligohydramnios had a significantly betterperinatal outcome than those with persistentoligohydramnios inspite of amnioinfusion. Howeverthey did not have a control group. They used ritodrinetocolysis whenever indicated. They noted fiveintrauterine deaths in 25 cases with persistentoligohydramnios. They could successfully infuse all thewomen but only 30% retained the fluid after 48 hours. Inour study also only one out of the three successfullyinfused cases with PPROM, retained the fluid after 48hours. We encountered one intrauterine death in thestudy group. Turhan and Atacan" performedamnioinfusions in 15 cases with mixed diagnosis withmean gestational age of 29 weeks. They included 14controls and demonstrated a significant increase in

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R Gowri et al

Table I. Distribution of the Variables in the Three Groups.

Control Group

n=9

Study Group

Successful AI Failed Aln=5 n=3

Baseline AFI (em)

Period of gestation (weeks)

Birth weight (kg)

PROM (numbers)

3.02 ± (1.33)

28

1.12

7

3.06 ± (1.55)

31.5

1.5

3

2.2

28

1.19

3

AFI = amniotic fluid index AI = amnioinfusion. PROM = premature rupture of membranes

TABLE-II. Outcome Parameters in the Three Groups

Control Group Study Group

Successful AI FAILED AIN=9 N=5 N=3

Mean increase in AFI over 1.26 ± 1.37a

3.67 ± 1.78a

048 hours in em .

Latency period of pregnancy indays [Median (Range)] 9 (1-63) 16 (1-35) 3(1-20)

Cesarean section 1 1 0

Abnormal intrapartum fetalheart rate pattern 6 2 1

Number of still births 4 (44%) 2 (40%) 1(33%)

Number of neonatal deaths 3 2 0

Survivors 2 (22.2%) 1 (20%) 2 (66.7%)

a p=0.0146 AI = amnioinfusion

amniotic fluid index and latency period. However theyfound similar perinatal outcome in the two groups.

In our study also we found a significant increase inamniotic fluid index and an apparent increase in latencyperiod of pregnancy in the amnioinfused group.However this did not translate into perinatal

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benefits. Our hospital being a tertiary caregovernment hospital with over 10,000 deliveries ayear has a heavy burden on neonatal intensive careunit. The resulting cross infection and poorpurchase power of women for speciali zedtreatment in general, results in high p erinatalmortality rates specially in preterm deliveries .

The paucity of cases in the two groups was ashortcoming of our study.

Transabdominal amnioinfusion is a safe procedure.It increases the amniotic fluid index significantly. Butthis benefit did not translate into perinatal survivalbenefits in our study. A larger randomized controlledstu d y needs to be done to demonstrate perinatalsurvival benefits of this procedure before it can berecommended for preterm oligohydramniosespecially in our country with very high perinatalmortality, more so in preterm deliveries.

Acknowledgement

The study was performed while Dr. R. Gowri wasworking as a senior research associate under the poolscheme in the Council of Scientific and IndustrialResearch (CSIR). This study was partly funded by theCSIR.

References

1. Peipert J F, Donnenfeld AE. Oligohydramnios: AReview. Obstet Gynecol Surv1991; 46: 325-35.

Evaluation of Transabdominal Amnioinjusion

2. Fisk NN, Ronderos- dumit D, Soliani A et al.Diagnostic and therapeutic amnioinfusion inoligohydramnios. Obstet Gynecol1991; 78: 270-8.

3. Sarno P, Polzin WJ,Malow A. Transabdominalamnioinfusion in preterm pregnancies complicatedby fetal growth restriction and oligohydramnios,umbilical cord compression. Fetal diagnosis andtherapy 1995;10: 408-14.

4. Garzetti GC, Ciavattini A, Decritofaro F et al.Prophylactic amnioinfusion in oligohydramniosfor preterm premature rupture of membranes:increase of amniotic fluid index during latencyperiod. Gynecological and Obstetric Investigation1977;44:249-54.

5. Locatelli A, Vergani P, Pirro G D et al. Role ofamnioinfusion in the management of prematurerupture of the membranes at <26 weeks gestation.Am JObstet Gynecol 2000; 183: 878-82.

6. Turhan NO, Atacan N. Antepartum prophylacticamnioinfusion in preterm pregnanciescomplicated by oligohydramnios. Int J GynaecolObstet 2002; 76:15-21 .

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