Management Of Post Term Pregnancy

MANAGEMENT OF POST TERM PREGNANCY INTRODUCTION/HISTORICAL MILESTONES 1. BALANTYN IN 1902—FIRST REFERENCE TO POST TERM

PREGNANCY 2. CLIFFORD IN 1954—DESCRIBED POSTMATURITY SYNDROME 3. AUBERG IN 1964 & LANMAN IN 1968—INCREASED PERINATAL DEATH IN PROLONGED PREGNANCIES 4. PROMINENCE IN LAST DECADE—HIGH RISK CONDITION 5. OPTIMAL MANAGEMENT STILL CONTROVERSIAL  OLD SCHOOL—EXPECTANT CONSERVATIVE MGT.  OTHER SCHOOL—“ACTIVE MGT” DELIVERY AT 42/52. 6. MORE RECENTLY, EVIDENCE BASED STUDY—PLANNED DELIVERY AT 41 WEEKS ( RHL-6) 7. PROLONGED PREGNANCY, POSTTERM, AFTER-TERM PREGNANCY—SYNONYMS (THE LANCET) 8. POSTMATURITY, HYPERMATURITY & DYSMATURITY— CLINICAL SYNDROMES IN NEONATES MORE COMMON IN POSTTERM, BUT ALSO DESCRIBED IN TERM INFANTS.

DIAGNOSIS SOMETIMES DIFFICULT  ILLITRACY IS RAMPANT—LMP WILL BE UNKNOWN  LATE BOOKING  NO EARLY USS. HX INVOLVES AMONG OTHER THINGS:  PARITY— PRIMIGRAVIDAE  MULTIPS—PREVIOUS HX  LMP—1ST DAY LMP

-DATE OF MISSED PERIOD AS LMP - IRREGULAR CYCLES - MENSTRUAL RECALL INACURRATE IN 20-40% - TIMING OF OVULATION ERRATIC IN SOME WOMEN.

EXAMINATION GENERAL- PALLOR, FEVER, JAUNDICE, PEDAL EDEMA SYSTEMIC  CVS- HYPERTENSION=IUGR  ABD—SIZE,  ----FH =36/52, <36/52—IUGR, LIGTHENING ----LIE, PRESENTATION, DECENT, FHR  PELVIC EXAMINATION --EXCLUDE PELVIC CONTRACTION --CERVICAL ASSSESMENT

BISHOP SCORING PARAMETER POSITION OF

0 1 POSTERIOR CENTRAL

2 3 ANTERIOR

CX CONSISTENCY FIRM

MEDIUM

SOFT

OF CERVIX CERVICAL

0-40%

40-60%

60-80%

+80%

EFFACEMENT CERVICAL

CLOSED

1-2CM

3-4CM

5CM +

DILATATION STATION OF

-3

-2

-1

+1, 2

PP

INTERPRETATION OF BISHOP’S SCORE  0-4: CERVIX UNFAVORABLE  5-8: MODERATELY FAVORABLE  9-13: CERVIX “RIPE” PREDICTIVE OF SUCCESSFUL INDUCTION

INVESTIGATIONS GENERAL—HB, GENOTYPE, BLOOD GROUP, CROSSMATCH 2 UNITS OF BLOOD, URINALYSIS

OTHERS:

PREGNANCY DATING 1. CLINICALLY  LMP-- SPOUSE MAY KNOW

 UNCERTAIN IN, LAM/CONTRACEPTIVES,  ABORTION PRECEEDING PREGNANCY ACCURATELY KNOWN IN ASSSISTED CONCEPTION-INVITRO FERTILIZATION (38WEEKS). --QUICKENING 16-18 WEEKS- MULTIPS 18-20 WEEKS- PRIMIPS --HEGAR’S--- +VE IN 6 WEEKS ( SOFTENING OF Cervix --FH PRESENCE OF PELVIC TUMOR, INFLUENCE THE FH ---FETAL HEART SOUNDS 16 WEEKS- WITH SONICAID 24-28 WEEKS- WITH PINARD 2. LABORATORY STUDIES 3. SERUM PT- +VE 6-7 DAYS AFTER CONCEPTION (CHEMICAL PREGNANCY) o URINE PT-- +VE IN 5 WEEKS 4. RADIOLOGICAL STUDIES  ULTRASONOGRAPHY

 1ST TRIMESTER—BEST, MARGIN OF ERROR -3

DAYS -GESTATIONAL SAC (5-7 WEEKS) -CRL (8-12 WEEKS)  2ND TRIMESTER- RELIABLE, MARGIN OF

ERROR- 7 DAYS --BPD- Preferred, --FEMUR LENGTH, HEAD CIRCUMFERENCE, --ABDOMINAL CIRCUMFERENCE  3rd TRIMESTER- NOT RELIABLE, MARGIN OF

ERROR- 14 DAYS --ESTIMATION OF FETAL WEIGHT --BIOPHYSICAL PROFILE SCORING --PLACENTAL MATURITY --CONGENITAL ABNORMALITIES

BIOPHYSICAL PROFILE SCORING (MAX= 10) PARAMETER Amniotic fluid volume

SCORE 2 >2cm pocket

SCORE 0 <2cm,

Fetal movements

3 or more gross body

oligohydramnious 2 or less

Breathing movements

movement 30seconds of sustained

< 30 seconds of

Fetal tone

fbm in 30 minutes One episode

sustained fbm No evidence of

flexion/extension in

movements

succession 2 or more rapid

<2 accelerations

Fetal reactivity( FHR)

accelerations in 40 minutes Interpretation of score  8-10 = normal score

 6-7 = repeat  < 6 =terminate pregnancy

PLACENTAL MATURITY GRADING ( 0-3)

GRADE O

1st trimester. Smooth chorionic plate, no echogenic areas of calcification 14- 34 weeks, indentation of chorionic plate, echogenic areas of calcification 26- 36 weeks. More indentation of chorionic plate, sparing the basal plate. >38 weeks. Indentation to the basal plate. Extensive echogenic areas of calcifications

GRADE 1 GRADE 2 GRADE 3

5.ROENTGENOGRAPHY THE APPEARANCE OF OSSIFICATION CENTRES IN FETAL BONES MAY BE USED TO DATE PREGNANCY.  35- 40 WEEKS- distal femoral epiphysis  37-42 WEEKS- proximal tibial epiphysis appears. --NO LONGER USED FOR PREGNANCY DATING.

MANAGEMENT OPTIONS 1. “ACTIVE MANAGEMENT”- DELIVERY AT 41/42 WEEKS 2. EXPECTANT CONSERVATIVE MANAGEMENT THIS ENTAILS FETAL SURVEILLANCE, which include  Cardiff 10 count—10 fetal kicks in 12hours(normal)  Regular fundal height estimation  Non-stress test--normal(110-150bpm, baseline variability OF 5-25 BPM  Weekly contraction stress test—time wasting, invasive

 Amnioscopy/ Amniocentesis- L/S ratio, meconium staining of amniotic fluid  Weekly fetoplacental function test—plasma free estriol, HPL. No longer in use, expensive  USS- As mentioned earlier  Doppler velocimetry—of umbilical artery= absence of end diastolic suggests fetal compromise

ACTIVE MANAGEMENT DELIVERY AT 41/42 WEEKS  CERVICAL ASSESSMENT/BISHOP’S SCORING  IF UNFAVORABLE, RIPEN CERVIX WITH Prostaglandin E1, E2 Forley’s urethral catheter Laminiara tent Membrane sweeping

INDUCTION—when cervix is favorable, informed consent  Surgical method --Amniotomy  Medical methods --Prostaglandin --Oxytocin infusion  Synchronous induction  Time lag between amniotomy/ oxytocin infusion (or vice versa) is less than 3hours.

LABOUR Some times prolonged. Increased risk of fetal distress. At least 2 units of blood should be cross matched. Senior resident/ experienced midwife, anaesthetist, neonatologist must be present. Theatre ideally should be informed. Vigilant intrapartum monitoring, preferably continuous electronic fetal heart rate monitoring, intermittent auscultation Fetal scalp electrode—pH Meconium staining of amniotic fluid- amnioinfusion with warm normal saline.

2ND STAGE Delivery taken by a senior resident. Risk of shoulder dystocia Neonatologist must be present for possible resuscitation Suck oropharynx at the delivery of the head if liquor is meconium stained. Hand over baby to neonatologist if asphyxiated.

3rd STAGE Should be managed actively. POST PARTUM Should be observed for 24 hours, and if satisfactory discharge home. COMPLICATIONS ANTENATAL  Oligohydramnious  meconium staining of amniotic fluid  postmaturity  intra uterine fetal death  placental insufficiency INTRAPARTUM  increased risk of meconium staining of the amniotic fluid  increased risk of meconium aspiration  dystocia  intrapartum fetal death NEONATAL nerve palsy—Erb’s palsy



 neonatal death  post neonatal death MATERNAL COMPLICATIONS 

maternal anxiety

 trauma

 increased caesarean section rate. CONCLUSION Post term pregnancy presents a mgt problem. While decision to terminate or to continue with pregnancy remain controversial, obstetric units should have policy based on evidence of favorable outcome.