POST TERM PREGNANCY

Definition

Literal meaning of prolonged pregnancy or post term

pregnancy is any pregnancy which has passed beyond

the expected date of delivery. But for clinical, post

term pregnancy is as a pregnancy equal to or more

than 42 completed weeks from the first day of the last

menstrual period.

Incidence

The incidence is varies from 2-10% because

different criteria in definition. According to

retrospective study of delivery beyond 290 days the

incidence is low as 2 %. Based on delivery beyond

42 weeks, the incidence come 10%. When an early

ultrasound scan is used the incidence is reduced

from 10% to 3% . (Hovi et al 2006)

CausesThe causes of post term pregnancy is unknown.

1. Previous post mature birth.

2. Irregular menstrual cycle.

3. Primi gravida

4. Elderly pregnancy

5. High socioeconomic status

6. Sendentary life style

7. Anencephaly without polyhydramnious

9. Male fetus (placental sulphatase deficiency)

10. Fetal adrenal hypoplasia

Symptoms of post mature baby:

Different babies will show different symptoms of postmaturity. Some postmature babies will show no or little sign of postmaturity. The most common symptoms are:

- Dry skin- Overgrowth nails- Creases on the baby’s palms and soles of their feet.- Minimal fat- A lot hair on their head - A brown, green or yellow discoloration of their skin

Diagnosis

1.Last menstrual period (LMP) : if mother is sure about her

date of menstrual cycle, it is fairly reliable diagnostic aid

in calculation of EDD. In case of mistakem pregnancy can

be occur any time like lactational amenorrhoea period or

withdrawl of pill which make confusion.

2. From date of quickening: normal quickening occurs

between 18-20 weeks pregnancy.

3. Fundal height

4. Suspected clinical findings: weight loss, girth of the

abdomen gradually diminishes because of diminishing

liquor volume, history of false pain, fundal height, fetal

part can be palpable on abdominal palpation, cervical

ripening on internal examination.

5. Investigations:

- Ultrasound

- X-ray abdomen

-Amniocentesis:- biochemical and cytological

paramiters may help in assessment of maturity.

Risk or Complications of Post- term Pregnancy

Maternal effects

i. Incidence cesarean section rate is double.

ii. Increased incidence of induction of labor, instrumental

delivery

iii. Risk of birth canal trauma and postpartum hemorrhage

iv. Prolonged labor or CPD due to large and mature skull

v. Increased anxiety and fear

Fetal effects

i. Chances of fetal hypoxia due to placental insufficiency

during pregnancy.

ii. IUGR 20%

iii. Larger than date of prenancy

iv. Fetal death may occur

v. Decreased liquor volume

vi. Increased risk of asphyxia and intracranial damage during

labor

vii. Muconium aspiration syndrome and atelectasis due to

intrauterine anoxia and inhalation of meconium

viii. Hypoglycemia and polycythemia in IUGR post term babies

ix. Increased perinatal and neonatal mortality and morbidity due

to low APGAR score.

Management of Post-term Pregnancy

Management of prolonged pregnancy must include an

accurate dating of the pregnancy to determine the pregnancy

is prolonged for that individual. The management is depend

on complicated or uncomplicated pregnancy.

1. Mother should admit in hospital and allowed to continue till

spontaneous onset of labor.

2. Periodic assessment of fetal wellbeing is to be done through

CTG to monitor fetal heart rate and AFI index so that early

evidence of fetal compromise can be deal.

3. Exclude all possible complication such as diabetes, CPD,

toxemia, Rh negative blood.

4. Induction of labor if spontaneous labor is not onset with 10-

14 days after EDD.

5. complicated post-term pregnancy like contracted pelvis, post

ceasarean pregnancy, malpresentation, elderly primigravida.

6. Association of complication like pre-eclampsia, history of

APH, diabetes, Rh-negative should not allowed to past the

expedted date of delivery

Induction of labor

The induction of labor is an intervention to initiate the

process of labor by artificial means in pregnancies from 24

weeks (period of viability) of gestation which aims at a

vaginal delivery. The decision to induce labour should only

be made when it is clear that a vaginal birth is the most

appropriate mode of delivery in this pregnancy,

Incidence

The incidence of induced labour varies in different hospital

but generally showing a rising trend about 10-15% in india

Indications of induction of labour

Maternal• Prolonged pregnancy• Hypertension including pre-clampsia to expedite the

delivery as severity of symptoms.• Pre-labour rupture of membranes (more than 24 hour)• APH• Elderly primigravidae• Minor degree of placenta praevia• Chronic renal disease• Abruptio placenta

Fetal• Intrauterine growth restriction• Macrosomia• Fetal death• Previous unexplained IUD• Gross congenital anomalies of the fetus• Post maturity• Chronic placental insufficiency• Rh-isoimmunization• Unstable lie • Multiple pregnancy

Contraindications• Contracted pelvic• Malpresentation(transverse or oblique)• Known CPD• Prematurity• Cardiac disease• Elderly primigravida associated with complication• Pelvic tumor• Previous caesarean section• Carcinoma of cervix• Active genital herpes infection• Umbical cord prolapsed• Severe actual fetal compromise• Placenta praevia

Methods of induction

Prior to any method used to induce labour, it is extrem ely

important for the midwife to carry out an abdominal

examination confirming the lie, presentation, descent of

presenting part and fetal wellbeing. Before starting the

induction condition of the cervix should assess, cervical

exam is to be performed.The bishop’s sore should 6 or more

than 6 is favourable for induction, below 5 is unfavourable

for induction.

The common methods used for induction of labor are:

1. Medical induction

2. Surgical induction

3. Combined

Medical Induction

In medical induction the drugs are used for labour

induction.

Indications:

i) Exclusive

- Intrauterine death (IUFD)

- Premature rupture of the membrane (PROM)

ii) In case of failure of surgical induction as an

alternative to caesarean section.

Drugs:

• Oxytocin

• Prostaglandin

Oxytocin

Oxytocin is a hormone released from the posterior

pituitary gland. It acts at cell level on smooth muscle and

is released in a pulsed manner in response to stimulation.

Receptor to oxytocin are found in myometrium and

increase in number at the terms and throught labour.

Principles of Induction of Labour

1. The oxytocin should be started at low dose but increases quickly where there is no response because its erractic response.

2. When the optimal responses are achieved (severe uterine contraction), the administration of the particular concentration in mu/min is to be continued. This is called oxytocin titration technique.

3. The objective of oxytocin administration is not only to initiate effective contraction but also maintain normal pattern of uterine activity till delivery and at least 30-40 minutes beyond that.

Regime of oxytocinMultigravidae uterus or the uterus which is already

contracting is much more sensitive to oxytocin. In this

respect , the primigravidae uterus is less sensitive.The

patient should preferably lie on one side or in semi-

fowler’s position to minimize vanacaval compression.

1. First regimine:- Mix 2.5 unit syntocin in 500 ml of

destrose or ringer’s lactate and start at 10 drops/minute

to evaluate the sensitivity of the patient to drugs.

Theafter increase the drop rate gradually with 10 drops

in every 30 minutes up to 60 drops per minute

depending on the response that is frequency and

strength of uterine contraction.

If good contraction pattern has not obtained with the infusion rate

at 60 drops/min, increase oxytocin concentration to 5 units in

500ml dextrose or normal saline or ringer lactate.

Second regime:

5 units of oxytocin added to 500 ml dextrose and give

approximated 0,5 mu in one drop of infusion. The starting dose low

as 30 drops per minute (5 mu), increase the 10 drops at 30 minute

intervals and maximum of 60 drops per minute (30mu/min)

according strength and frequency of uterine contraction. If good

contraction pattern still has not been establishe using higher

concentration of oxytocin in multigravida and with previous C/S

scare, induction has failed deliver by caesarean section.

Observation during oxytocin infusion• Moniter the mother’s pulse, blood pressure and contractions and

check fetal heart rate.

• Review for inductions, be sure induction is indicated as failed

induction is usually followed by caesarean section.

• Ensure that mother is on her left side.

• Record the rate of infusion, duration and frequency of contration

and fetal heart rate on a partograph every 30 minutes.

• Moniter FHS every 30 minutes, always immediately after

contraction. If FHS is less than 100 bpm, stop the infusion and

manage for fetal distress.

• Mother receiving oxytocin should never be left alone.

• Increase the infusion rate 10 drops per minute every 30 until

good contraction pattern is established ( 3contraction in 10

seconds and each lasting 40 seconds).

• Maintain this rate till delivery is completed.

• If hyperstimulation occurs ( 4 contraction in 10 minute and

each contraction lasts longer than 60 seconds), stop the

infusion and relax the uterus using tocolytics such as:

– turbutaline 250 mcg IV slowly over 5 minutes

– Or salbutamole 10 mg in 1 liter IV fluids at 10 drops per minute.

• Do not use oxytocin 10 units in 500 ml (20mIU/min)

in multigravida and women with previous C/S.

• Infuse oxytocin at higher concentration (10 unitsin

500 ml) in primigravida.

• If good contraction are not established at the

maximum dose, deliver by caesarean section.

PROSTAGLANDIN

Prostaglandins are highly effective in ripening of cervix during

induction of labour. Bishop’s score should be assessed before

using prostaglandin for the cervix is fabourable or not.

Indications:

• Medical termination of pregnancy

• Termination of abnormal pregnancy

• Missed abortion

• IUFD

• Molar pregnancy

• Major fetal abnormality like anencephaly

Procedure• Moniter the woman’s pulse, blood pressure and

contraction and check the fetal heart rate.

• Record findings on a partograph.

• Review for inductions

• The prostaglandin is placed high in the posterior fornix of

the vagina and may be repeated after six hours if required.

• Moniter uterine contraction and fetal heart rate of all

women undergoing induction of labour with

prostaglandins.

• Discontinue use of prostaglandins and begin oxytocin infusion

if:

– Membrane rupture

– Cervical ripening has been achieved

– Good labour has been established

– Or 12 hours have passed.

Misoprostol

• Use misoprostol to ripen cervix only in highly selected situations

such as: severe pre-eclampsia when the cervix is unfavourable

and safe C/S is not immediately available or the baby is too

premature to survive.

Fetal death is utero if the woman has not gone into spontaneous

labour after four week and platelets are decreasing.

• Place misoprostol 25mcg in the posterior fornix of the vagina.

Repeat after six hours if required.

• If there is no response after two doses 0f 25cmg, increase to 50

mcg every six hours.

• Do not use more than 50mcg at a time and do not exceed foru

doses (200mcg)

• Do not use oxytocin within 8 hours of using misoprostol.

Moniter uterine contractions and fetal heart rate.

Surgical inductionThe initiation of labour is attempt by surgical method and is almost

exclusively done by rupture of the membranes.

Indication:

1)APH

2) Chronic polyhydramnious

3) Severe pre-eclampsia and eclampsia

4) As combined with medical induction

Contraindication:

i. IUFD

ii. Moderate to severe CPD

iii. Abnormal lie

Combined Method

• Refer midwifery B book

Procedure• Review for indication

• In areas where HIV and/or hepatitis are highly prevalant, it should

leave the membranes intact for as long as possible to reduce perinatal

transmission of HIV.

• Listen and note the fetal heart rate.

• Ask the woman to lie on her back with her legs bent, feet together

and knees apart.

• Wearing high- level disinfected or sterile gloves, use one hand to

examine the cervix and note the consistency, position, effacement and

dilatation.

• Use the other hand to insert an amniotic hook or a kocher clamp into

the vagina.

• Guide the clamp or hook towards the membranes along the fingers in

the vagina

• Place two fingers against the membrabes and gently

rupture the membrane with the instrument in other

hand. Allow the amniotic fluid to drain slowly around

the fingers.

• Note the color of the fluid(clear, greenish, bloody), If

thick meconium is present, suspect fetal distress.

• After ARM listen FHS during and after a contraction.

If FHS is abnormal (less than 100or more than 180

bpm) suspect fetal distress.

• If membrane have been ruptured for 18 hours give

prophylactic antibiotics to reduce group B streptococcus

infection in neonate. Penicillin G 2 million units IV or

Ampicilin 2 g IV every 6 hours until delivery. If there is no

sign of infection after delivery discontinue antibiotics.

• If good labour is not established one hour after ARM

begin oxytocin infusion.

• If labour is induced because of severe maternal disease,

begin oxytocin infusion at the same time as ARM.