Prolonged Pregnancy And Placental Insufficiency Flashcards
What is prolonged/ Post term pregnancy?
Any pregnancy that lasts 42 completed weeks or more, or 294 days or more
Incidence of prolonged pregnancy
5-10% of pregnancies
Causes/Risk Factors of prolonged pregnancy
Wrong dating (commonest) Can be idiopathic Nulliparity Previous prolonged pregnancy (50% risk) Placental sulphatase deficiency (X linked recessive) Fetal adrenal insufficiency/hypoplasia Anencephaly Male sex Genetic factors Obesity
How is diagnosis of prolonged pregnancy made?
Based on accurate dating of pregnancy.
Methods used to Date Pregnancy - LMP
- Use of LMP
Assumes accurate recall of date and ovulation on the 14th day of the cycle in a 28 day cycle
🌟Naegle’s rule is based on assumpof a 28 day cycle
🌟Errors can be due to inaccurate patient recall, maternal preference of date of LMP, and random error.
Methods of Pregnancy Dating - Ultrasound
1st Trimester scan most accurate at determining Gestational age. Measures the crown-rump length (CRL; error of +/- 5 days)
🌟Fetal biometry in 2nd Trimester is accurate for dating (error +/- 10 days)
🌟Biometry is most accurate if 2 or more parameters, such as biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length are used together.
🌟With several USG scans, gestational age should be determined by earliest scan (1st trimester scan dating more reliable than LMP)
Other methods of dating
Less reliable: Quickening @ 18 weeks (usually)
🌟SFH measurement- 1st SFH measurement on ANC card is fairly accurate and can be used to extrapolate to calculate gestational age.
Risks of Prolonged pregnancy to the Fetus
🌟Increased mortality/morbidity 🌟Macrosomia 🌟Low apgar scores and cord pH 🌟Post maturity syndrome - in 20% 🌟Oligohydramnios 🌟Neonatal encephalopathy 🌟Cord compression 🌟Meconium aspiration syndrome 🌟Fetal distress 🌟Placental dysfunction ❤️Post term 🌟Death in 1st year of life
Deliver Complications of Prolonged Pregnancy
🌟Labour dysfunction 🌟Shoulder dystopia 🌟Obstetric Trauma 🌟Meconium aspiration 🌟Birth injuries - fractured bones, peripheral nerve damage 🌟Increased risk of C/S delivery 🌟Fetal and neonatal death 🌟Chorioamnionitis 🌟PPH 🌟Maternal emotional impact
Neonatal Complications of Prolonged Pregnancy
🌟Meconium aspiration syndrome (in 5% of meconium stained liqour) 🌟Asphyxia 🌟Hypoglycemia 🌟Pneumonia 🌟Septicemia
General Principles in Management of Prolonged Pregnancy
🌟Conservative
🌟Induction of Labour
🌟Elective C/S
Conservative measures for Prolonged pregnancy
Onset of Labour can be awaited for a couple of days after 42 weeks.
🌟While waiting, institute fetal surveillance.
🌟Kick counts
🌟Fetal Doppler
🌟CTG - NST
🌟Amniotic Fluid Index (AFI)
🌟Biophysical profile
Induction of Labour
Immediate IOL indicated if there is: 🌟Oligohydramnios 🌟IUGR 🌟Reduced Fetal movements 🌟Abnormal CTG findings 🌟Concurrent medical condition
Ensure the following before induction:
🌟Accurate dating to avoid delivery of preterm Fetus
🌟There is no obstetric contraindication to vaginal delivery
🌟Favourable cervix (Bishop Score >/=6)
🌟Fetus can withstand vagaries of labor (can do contraction stress test
🌟Use of electronic fetal monitoring in labor
Counseling in IOL - Prolonged pregnancy
💃🏾Let patient understand that after 42 weeks, perinatal mortality increases 2-fold and no test can guarantee safety of baby.
💃🏾Inductors likely to fail due to abnormal uterine contractions and may be abandoned because of fetal distress.
💃🏾Routine induction at 41+0 to 41+6 does not increase the C/S rate and may decrease it without negatively affecting perinatal morbidity or mortality.
Prevention of Prolonged Pregnancy
🌟Accurate dating of Pregnancy 🌟1st Trimester USG for all pregnancies 🌟Active measures to end pregnancy after 41 weeks 🌟Membrane sweeping 🌟Nipple stimulation 🌟Elective IOL
Membrane Sweeping/Stripping
🌟Recommended after 38 weeks
🌟Release local prostaglandins that stimulate uterine contractions
🌟Theoretical risks include: Chorioamnionitis, PROM, bleeding from an undiagnosed placenta praevja
Nipple stimulation
Frequent Nipple stimulation by patient causes oxytocin release (like let down reflex)
Elective IOL
🌟Women should be offered IOL at 41+0 to 42+0 weeks
🌟Evidence of decrease in perinatal mortality without increased risk of C/S
The PostMaturity Syndrome (PMS)
Infants with characteristics of chronic intrauterine growth restriction from uteroplacental insufficiency.
🌟Undernourished fetus suffering because of placental aging and chronic dysfunction.
🌟Described as small old man
🌟Not limited to post dates pregnancy, but can occur earlier when placental insufficiency occurs
🌟20% of post dates babies have PMS
🌟Synonymous with dysmaturity
Features of PMS + when diagnosis is made
Diagnosis is made after delivery when the following features are present.
🌟Absence of vernix Caseosa and lanugo hair 🌟Abundant scalp hair 🌟Long fingernails 🌟Dry, cracked desquamated skin 🌟Alert and apprehensive facies 🌟Meconium staining of skin and membranes
Complications of PMS
🌟Ossification of fetal bones 🌟Macrosomia , that may lead to CPD/Prolonged labor/Shoulder dystocia 🌟Placental insufficiency 🌟Oligohydramnios 🌟Cord compression (due to Oligohydramnios 🌟Increased risk of C/S and PPH 🌟IUD/Still Birth 🌟Hypoglycemia 🌟Hypothermia 🌟Meconium aspiration syndrome
Placental Insufficiency
A complication of pregnancy- Placenta cannot deliver enough oxygen and nutrients to the fetus and adequately remove waste material.
🌟The earlier in pregnancy this occurs, the severer the complications
🌟May lead to IUGR if present for a long time.
Pathology (Etiology of Placental Insufficiency)
1 impairment in maternal circulation- from maternal hypertension/ maternal thrombophilic disorders
- Impairment in fetal circulation - placental implantation over a fibroid.
- Vascular thrombosis- eg. Placental infarction
Risk factors for Placental Insufficiency
🌟SGA Fetus 🌟Previous SGA infant 🌟Post term pregnancy 🌟Elderly primigravida 🌟Hypertensive disorders 🌟Diabetes 🌟Renal disease 🌟Multiple pregnancy 🌟Anemia in pregnancy
Diagnosis of Placental Insufficiency- Signs that should arouse suspicion
🌟Poor maternal weight gain
🌟Static fundus
🌟Diminished liqour volume
🌟Reduced fetal kicks/movements
Diagnosis - Confirming suspicion of placental insufficiency
🌟Meconium stained liquor on amnioscopy 🌟Abnormal non-stress tests 🌟Serial biochemistry measurements 🌟Decreased estriol 🌟Decreased hPL 🌟Increased alpha detox-protein and hCG in 2nd Trimester
Ultrasound
💃🏾Biometric measurements - HC:AC ratio
💃🏾Uterine artery Doppler in 2nd Trimester
💃🏾Placental morphology in 2nd Trimester - shape and texture.
Management of Placental Insufficiency
🔥Treat any underlying medical condition
🔥Adequate bed rest
🔥Stop smoking and drinking
🔥Deliver baby at optimum time
Complications of Placental Insufficiency
🌟Abortions 🌟Stillbirths 🌟Preterm delivery 🌟IUGR 🌟Low birth weight 🌟Cerebral palsy 🌟Abruptio placentae
