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
