POST-TERM PREGNANCY
Definition :
“ A pregnancy continuing beyond 2 weeks of the expected date of delivery (>294 days ) is called post maturity or post-term delivery “
INCIDENCE :
- The incidence of pregnancies continuing beyond 42 completed week (>294 days ) ranges between 4 and 14 %
- The average is about 10%
- Many post term pregnancy are actually wrongly dated
ETIOLOGY :The etiology (causes) of post-term delivery is not fully understood but is thought to involve a combination of factors:
- Unknown Factors :
- In many cases, the exact cause of why some pregnancies go post-term is unknown.
- It could be related to genetic or environmental factors that influence the timing of labor onset.
- Placental Function :
- As the pregnancy progresses beyond term, the placenta may not function as efficiently.
- This could lead to reduced nutrient and oxygen supply to the fetus, prompting the initiation of labor to facilitate delivery.
- Sulfatase deficiency leads to low estrogen
- Maternal Factors :
- Primiparity
- Previous prolonged pregnancy
- older maternal age or obesity.
- Sedentary habit
- These factors can affect hormonal balance and uterine function.
- Fetal Factors :
- Fetal factors, such as genetic predisposition, fetal size, and gender, may also play a role in determining the timing of labor onset.
- Congenital anomalies
- Anencephaly
- Progesterone Withdrawal :
- Towards the end of pregnancy, there is a withdrawal of progesterone and an increase in prostaglandins, which are involved in initiating labor.
- The balance of these hormones may influence the onset of labor.
- Inaccurate Estimation of Gestational Age :
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Sometimes, errors in estimating the gestational age of the fetus can lead to a misclassification of post-term pregnancy.
- Biological variability ( hereditary ) may be seen in family
- Environmental Factors :
- There is some evidence that environmental factors, such as seasonal variations or sunlight exposure, may influence the timing of labor onset, although the exact mechanisms are not well understood.
INVESTIGATION :
Investigations in post-term delivery focus on assessing the well-being of both the mother and the fetus, as well as determining the best course of action to manage the pregnancy. Here are key investigations commonly performed in cases of post-term delivery:
Fetal Assessment:
- Fetal Monitoring: Continuous or intermittent electronic fetal monitoring is used to assess fetal heart rate patterns and detect signs of distress.
- Biophysical Profile (BPP): A BPP combines ultrasound assessment of fetal movements, muscle tone, breathing movements, and amniotic fluid volume. It provides an overall assessment of fetal well-being.
- Non-Stress Test (NST): This test monitors fetal heart rate in response to fetal movements, providing information about fetal oxygenation and overall health.
- Amniotic Fluid Assessment: Ultrasound evaluation to measure amniotic fluid volume helps assess placental function and fetal well-being.
Maternal Assessment:
- Labor Progress Assessment: Monitoring the progress of labor, including cervical dilation, effacement, and descent of the fetus.
- Maternal Vital Signs: Regular monitoring of maternal blood pressure, pulse, and temperature to detect any signs of maternal distress or infection.
Additional Investigations:
- Biophysical Profile (BPP): This test combines ultrasound assessment of fetal movements
MANAGEMENT OF POST TERM PREGNANCY :
Managing post-term delivery involves several considerations to ensure the well-being of both the mother and the baby. Here are some key aspects:
- Monitoring and Assessment: Continuous monitoring of fetal well-being through non-stress tests (NST), biophysical profiles (BPP), or other appropriate methods helps determine if delivery is necessary.
- Induction of Labor: If fetal monitoring indicates a risk or if the pregnancy has extended beyond 41-42 weeks (depending on guidelines), induction of labor may be recommended to reduce the risks associated with post-term pregnancy.
- Risks and Complications: Educating the mother about the risks of post-term pregnancy, such as macrosomia (large baby), meconium aspiration syndrome, and placental insufficiency, helps in making informed decisions.
- Methods of Induction: Methods for inducing labor may include prostaglandins, oxytocin, or mechanical methods such as Foley catheter or membrane sweeping, chosen based on the cervix status and other medical considerations.
- Monitoring Labor: Continuous monitoring during labor ensures timely intervention if complications arise, such as fetal distress or uterine hyperstimulation.
- Supportive Care: Providing emotional support to the mother and ensuring she is informed about the process of induction and labor can help reduce anxiety and promote a positive birth experience.
- Mode of Delivery: Vaginal delivery is typically encouraged if conditions permit, but cesarean delivery may be necessary if there are complications or if labor fails to progress.
- Post-Delivery Care: Monitoring the baby post-delivery for any signs of complications associated with post-term birth, such as hypoglycemia or respiratory distress, is essential.
- Maternal Health: Monitoring the mother for any signs of postpartum complications, such as hemorrhage or infection, and providing appropriate care.
- Follow-Up: Ensuring follow-up care for both the mother and the baby to address any lingering issues or concerns that may arise after discharge from the hospital.
Each case of post-term delivery is unique, and management should be tailored to the specific circumstances and the health of both the mother and the baby. Close collaboration between obstetricians, midwives, and other healthcare providers ensures comprehensive care and optimal outcomes.
