Obgyn T 22-45 Flashcards
- What percentage of conceptions are affected by fetal abnormalities?
Over 50% of conceptions are affected by fetal abnormalities.
What is the percentage of fetal abnormalities in miscarriages and deaths between 20 weeks gestation and 1 year postnatal?
About 70% of miscarriages and 15% of deaths between 20 weeks gestation and 1 year postnatal are associated with fetal abnormalities.
What is a major congenital abnormality?
A major congenital abnormality is one that results in the death of the baby or severe disability.
What are the most common types of neural tube defects?
The most common neural tube defects include anencephaly, microcephaly, spina bifida (with or without myelomeningocele), encephalocele, holoprosencephaly, and hydranencephaly.
What is the outcome for infants with anencephaly or microcephaly?
Infants with anencephaly or microcephaly usually do not survive, with many dying during labor or within the first week of life.
How can the risk of neural tube defects be reduced?
Pre- and periconceptual folic acid supplementation (400 μg/day) can reduce the incidence of neural tube defects. Women with a history of neural tube defects in pregnancy are advised to take dietary folic acid supplements.
How are congenital cardiac defects detected?
Congenital cardiac defects can be diagnosed by real-time ultrasound imaging, particularly using four-chamber views during the 18-week gestation scan.
What are the most common congenital cardiac defects?
The most common congenital cardiac defects include ventricular and atrial septal defects, pulmonary and aortic stenosis, coarctation, and transposition (including tetralogy of Fallot).
What is the difference between gastroschisis and exomphalos?
Gastroschisis is a defect where the bowel protrudes outside the abdominal cavity without peritoneal covering, separate from the umbilical cord. Exomphalos is a hernia of the umbilical cord with a peritoneal covering, often associated with chromosomal abnormalities.
What characterizes Down’s syndrome (DS)?
Down’s syndrome is characterized by abnormal facial features, varying degrees of mental retardation, and congenital heart disease. It is caused by an additional chromosome on group 21.
How does maternal age affect the risk of Down’s syndrome?
The risk of Down’s syndrome increases with advancing maternal age due to a higher frequency of nondisjunction during meiosis.
What methods are used in screening for fetal abnormalities?
Screening methods include identifying clinical risk factors, using ultrasound (US), and performing biochemical testing of maternal serum.
What is the combined screening test for Down’s Syndrome (DS) in the first trimester?
The combined screening test for DS includes using ultrasound (US) and biochemistry, performed towards the end of the first trimester, along with a detailed US scan at around 20 weeks.
What should be offered if a woman misses the first-trimester Down’s Syndrome (DS) screening?
If a woman misses the first-trimester DS screening, a biochemical screening test should be offered at about 16 weeks.
What are the clinical risk factors in early pregnancy for fetal abnormality?
Clinical risk factors in early pregnancy include maternal age and risk of aneuploidy (especially DS), maternal drug ingestion (anticonvulsants, cytotoxic agents, warfarin), a previous history of fetal abnormality, and maternal diseases like diabetes and congenital heart disease.
What maternal drugs are associated with an increased risk of fetal abnormalities?
Maternal drugs associated with increased risk include anticonvulsants (CNS and neural tube defects), cytotoxic agents used in cancer therapy, and warfarin (especially when used in the first trimester).
What clinical risk factors are associated with fetal abnormality in late pregnancy?
Late pregnancy risk factors include persistent breech presentation or abnormal lie, vaginal bleeding, abnormal fetal movements, abnormal amniotic fluid volume (polyhydramnios or oligohydramnios), and growth restriction.
What are the two early ultrasound scans offered during pregnancy, and when are they done?
The first ultrasound is ideally between 11w+0d and 13w+6d to confirm fetal viability and gestation. The second ultrasound is offered at about 20 weeks.
What measurements are taken during the second ultrasound scan?
The second ultrasound measures fetal viability, head and abdominal circumferences, biparietal diameter, femur length, amniotic fluid volume, and performs an anatomical survey of organ systems.
How is the accuracy of Down’s Syndrome risk prediction increased in screenings?
The accuracy of DS risk prediction is increased by combining nuchal translucency (NT) measurements with biochemical markers such as β-hCG and pregnancy-associated plasma protein-A.
What does the ‘combined screening test’ for Down’s Syndrome consist of?
The combined screening test includes NT, β-hCG, and pregnancy-associated plasma protein-A (PAPP-A) and should occur when the crown-rump length (CRL) measures between 45-84 mm during ultrasound screenings.
What four chemicals are measured in maternal serum for Down’s Syndrome risk assessment?
The four chemicals measured are hCG, α-fetoprotein (aFP), unconjugated oestriol (uE3), and inhibin-A.
What further assessment options are available for women with an increased risk of chromosomal abnormalities?
Women with an increased risk of chromosomal abnormalities can undergo an invasive test, such as chorionic villus sampling (CVS) in the first trimester or amniocentesis in the second trimester, which provides information about chromosome number and structure but carries a 1% risk of miscarriage.
What imaging techniques can be used to clarify a suspected structural fetal abnormality?
Further imaging techniques include additional ultrasound (US) examinations after 1–2 weeks for better visualization or an MRI scan, especially useful for abnormalities of the central nervous system.
What follow-up test may be offered if a fetus is suspected of having a chromosomal abnormality based on anatomical appearances?
If anatomical appearances suggest a chromosomal abnormality, a CVS (placental biopsy in later pregnancy) or amniocentesis may be offered for further assessment.
What are possible interventions if further fetal abnormalities are confirmed?
Possible interventions include termination of pregnancy, maternally administered anti-arrhythmic drugs for fetal cardiac arrhythmias, or insertion of a vesico-amniotic drain to treat fetal urethral obstruction and prevent renal damage.
- What are key screening methods for fetal health in low-risk pregnancies?
Screening for low-risk pregnancies includes maternal vigilance for fetal activity, fundal height measurement (±3 cm range), and auscultation of the fetal heart using a Pinard stethoscope or Doppler ultrasound at every antenatal visit.
What is the significance of ‘absent end-diastolic flow’ (AEDV) in umbilical artery Doppler recordings?
AEDV indicates increased placental vascular resistance and is associated with worse outcomes such as growth restriction, hypoxia, and fetal death.
Management includes close surveillance or elective preterm delivery if occurring after 34 weeks.
What does ‘reversed diastolic flow’ in umbilical artery Doppler recordings suggest?
Reversed diastolic flow is a highly ominous sign, associated with imminent fetal death. Management depends on gestational age, and delivery may be discussed if the pregnancy is at 26 weeks or more.
How is fetal growth documented in at-risk pregnancies?
Fetal growth is best documented through serial ultrasound measurements of head circumference (HC) and abdominal circumference (AC), which help identify growth patterns and assess fetal wellbeing.
What are the characteristics of a constitutionally small fetus?
A constitutionally small fetus is typically genetically small, with no underlying pathological cause. It has a lower risk of complications compared to fetuses with growth restrictions due to other causes.
What is the difference between asymmetrical and symmetrical fetal growth restriction?
Asymmetrical growth restriction tends to occur later in pregnancy and is often associated with placental issues (UPVD), while symmetrical growth restriction indicates an early pregnancy insult and is linked to higher risks of hypoxia and fetal death.
How are large fetuses categorized in terms of growth?
Large fetuses can be constitutionally large, with both head circumference (HC) and abdominal circumference (AC) following the top centile, or large due to other factors like maternal diabetes.
- What are the screening methods for fetal health in low-risk pregnancies?
Screening in low-risk pregnancies includes maternal vigilance for fetal activity, fundal height measurement (±3 cm from gestational age), and auscultation of the fetal heart using a Pinard stethoscope or Doppler ultrasound at antenatal visits.
How is fundal height measurement used to assess fetal health?
Fundal height is measured from the maternal pubic symphysis to the uterine fundus. The normal range is within ±3 cm of the gestational age, e.g., at 32 weeks, the range should be 29–35 cm.
How is the fetal heart monitored during routine antenatal visits?
The fetal heart is auscultated at each visit using a Pinard stethoscope or Doppler ultrasound. While the rate is not typically recorded, any abnormalities in the fetal baseline heart rate may be missed in routine practice.
How does umbilical artery Doppler improve fetal outcomes in high-risk pregnancies?
Umbilical artery Doppler significantly improves fetal outcomes in high-risk pregnancies by assessing blood flow. Absent end-diastolic flow (AEDV) and reversed diastolic flow are key indicators of placental issues and potential fetal compromise.
What does ‘reversed diastolic flow’ indicate in high-risk pregnancies?
Reversed diastolic flow is a critical indicator of imminent fetal death, and management typically involves discussing elective preterm delivery if the pregnancy is at 26 weeks or beyond.
How is fetal growth documented in at-risk pregnancies?
Fetal growth is monitored through serial ultrasound measurements of head circumference (HC) and abdominal circumference (AC), which help identify small-for-dates and large-for-dates fetuses
What are the two patterns of suboptimal fetal growth recognized in small fetuses?
The two patterns are:
- Constitutionally small - due to genetic factors.
- Pathological growth restriction - either asymmetrical (later in pregnancy, often related to placental issues) or symmetrical (early pregnancy insult).
What are the risks associated with small-for-dates fetuses?
Small-for-dates fetuses, especially those with pathological growth restriction, are at higher risk of fetal death, hypoxia, preterm delivery, and placental bleeding.
How are large fetuses categorized in terms of growth?
Large fetuses can either be constitutionally large, with both head circumference (HC) and abdominal circumference (AC) following the top centile, or large due to other factors like maternal diabetes.
What is macrosomia in the context of fetal growth?
Macrosomia refers to pathologically large fetuses, where the head circumference (HC) follows a normal centile, but the abdominal circumference (AC) shows accelerated growth across centiles, commonly seen in fetuses of diabetic women.
How is amniotic fluid volume (AFV) assessed?
The most accurate estimate of AFV is via ultrasound, using two methods: 1) Single deepest pocket (normal range: 2–8 cm) and 2) Amniotic fluid index (AFI), which is the sum of fluid depths in four quadrants of the uterus.
What is the biophysical profile (BPP) and its significance?
The BPP is a combined assessment of fetal wellbeing using five parameters. A normal response is for the fetus to exhibit at least 4 parameters within 40 minutes, indicating immediate wellbeing.
What are the five observations used in the biophysical profile (BPP)?
The five observations are:
- Fetal heart rate (FHR) – at least 2 accelerations of 15 beats/min or more in 40 minutes.
- Fetal movements – at least 3 separate movements in 40 minutes.
- Fetal tone – one movement demonstrating a full flexion-extension-flexion cycle.
- Fetal breathing – sustained 30 seconds of regular breathing movements.
- Amniotic fluid volume (AFV) – at least one vertical pool measuring 2–8 cm.
What interventions are available when a risk to the fetus is proven by fetal surveillance?
When fetal risk is identified, the two valuable interventions are:
- Elective delivery (at or beyond 34 weeks) or based on immediate risk assessment.
- Maternal steroids, such as betamethasone, if elective preterm delivery is likely but only chronic fetal health measures are abnormal.
When is elective delivery considered in high-risk pregnancies?
Elective delivery is considered if the risk is identified at 34 weeks or more. If identified earlier, it depends on the immediate risk of fetal death based on assessments such as abnormal biophysical profile scores or reversed end-diastolic flow.
What are the indications for maternal steroid administration in at-risk pregnancies?
Maternal steroids, like betamethasone, are given if elective preterm delivery is likely in at-risk pregnancies but only chronic fetal health measures are abnormal, such as absent umbilical artery flow in Doppler studies.
What are some specific interventions for uncommon fetal risks?
Specific interventions include:
- Maternal drugs for fetal cardiac arrhythmias.
- Intrauterine blood transfusion for severe Rhesus isoimmunization.
- Laser ablation of placental vascular communications in twin-to-twin transfusion syndrome.
- What is labor (parturition)?
Labor, or parturition, is the process whereby the products of conception are expelled from the uterine cavity after the 24th week of gestation.
What percentage of deliveries occur at term and what percentage result in preterm labor?
About 93-94% of deliveries occur at term (between 37 to 42 weeks), while about 7-8% develop preterm labor and deliver preterm (from 24 to 37 weeks).
How is preterm labor defined?
Preterm labor is defined as labor occurring before the commencement of the 37th week of gestation. Before 24 weeks, it results in a previable fetus and is termed miscarriage.
What is prolonged labor and its significance?
Prolonged labor is defined as labor lasting in excess of 24 hours in a primigravida and 16 hours in a multigravida, and it is associated with increased fetal and maternal morbidity and mortality.
What occurs during the early preparation phase of labor?
The early preparation (pre-labor phase) can last for days and weeks, involving the softening, shortening, and dilation of the cervix, which accelerates with the onset of uterine contractions.
What are the three stages of observed labor?
The three stages of observed labor are:
- First Stage - from onset of regular contractions to full cervical dilation.
- Second Stage - from full cervical dilation to delivery of the fetus.
- Third Stage - from delivery of the newborn to delivery of the placenta and membranes.
Describe the phases of the first stage of labor.
The first stage is divided into:
Early Latent Phase: Cervix effaces and dilates up to 3 cm (~6-8 hours in nulliparae and 4-6 hours in multiparae).
Active Phase: Cervix dilates from 3 cm to full dilation (10 cm, approximately 1 cm/hour).
What is the second stage of labor?
The second stage of labor lasts from full cervical dilation to the delivery of the fetus, divided into:
Pelvic (Passive) Phase: Head descends down the pelvis.
Active Phase: Mother experiences a stronger urge to push, and the fetus is delivered with uterine contractions and maternal effort.
What occurs during the third stage of labor?
The third stage of labor is the duration from the delivery of the newborn to the delivery of the placenta and membranes.
What are the clinical signs of the onset of labor?
Clinical signs include:
Regular, painful contractions that increase in frequency and duration, leading to cervical dilatation.
Passage of blood-stained mucus (‘show’).
Rupture of fetal membranes, which may occur before or during labor.
How is prelabor rupture of membranes (PROM) defined?
Prelabor rupture of membranes (PROM) occurs when the latent period between rupture of membranes and the onset of painful contractions is greater than 4 hours, either at term or in the preterm period (preterm PROM).
What hormonal changes initiate labor?
The initiation of labor involves progesterone withdrawal and increases in estrogen and prostaglandin action, regulated by the fetoplacental unit, leading to upregulation of procontractile influences.
What is the role of maternal and fetal plasma CRH at the end of gestation?
At the end of gestation, there is an exponential increase in maternal and fetal plasma CRH levels, which increase estrogen synthesis and reduce progesterone synthesis, contributing to the initiation of labor.
What is the role of CRH in labor?
CRH stimulates the synthesis of prostaglandins, promotes connectivity of uterine myocytes, and alters myocyte electrical excitability, leading to increased uterine contractions.
How do uterine myocytes contribute to contractions?
Uterine myocytes contract and shorten, influenced by ion channels that control calcium ion influx, which promotes contraction of myometrial cells.
What changes occur in the cervix as it prepares for labor?
The cervix becomes soft and stretchable due to increased leukocyte infiltration, decreased collagen, and increased proteolytic enzyme activity, leading to cervical ripening.
What is the significance of hyaluronic acid in cervical changes?
Increased hyaluronic acid production reduces fibronectin’s affinity for collagen, causing the cervix to become soft and stretchable, facilitating ripening.
What are the essential factors for the progress of labor?
Reduced cervical resistance and increased frequency, duration, and strength of uterine contractions are needed for effective labor progress.
How does uterine activity change as labor approaches?
Uterine activity increases in frequency, duration, and strength of contractions as full term approaches, transitioning from infrequent, low-intensity contractions throughout pregnancy.
How is labor established in terms of contractions?
Labor is established with two contractions, each lasting more than 20 seconds, occurring over 10 minutes.
What are the characteristics of normal resting tonus during labor?
Normal resting tonus in labor starts at around 10-20 mmHg and may increase slightly.
How do contractions influence cervical effacement and dilation?
Progressive uterine contractions cause effacement and dilation of the cervix through shortening of myometrial fibers in the upper uterine segment and stretching of the lower segment.
What happens to the junction between the upper and lower uterine segments during labor?
As labor progresses, the junction between the upper and lower segments rises in the abdomen, and retraction may lead to Bandl’s ring visibility if labor is obstructed.
What is fundal dominance in uterine contractions?
Fundal dominance refers to contractions that are stronger and last longer in the fundus and upper segment, essential for effective cervical effacement and dilation.
What changes occur in the pelvic structure during labor?
Softening of the sacroiliac ligaments and pubic symphysis allows pelvic cavity expansion, facilitating normal progress and spontaneous vaginal delivery.
Describe the mechanism of labor regarding the pelvic inlet.
The pelvic inlet has a larger lateral diameter than anteroposterior diameter, promoting the head to engage in the pelvis in a transverse position.
What pattern does the head and trunk follow during passage through the pelvis?
The passage of the head and trunk follows a defined pattern: the upper pelvic strait is transverse, the middle is circular, and the outer is anteroposterior.
What is the normal presentation of the fetal head during labor?
The fetal head presents by the vertex in 95% of cases, considered the normal presentation.
What occurs during the descent phase of labor?
Descent is both a feature and prerequisite for birth, and the engagement of the head typically occurs before labor onset, serving as a measure of labor progress.
Describe the flexion process of the fetal head during labor.
As the head descends, it meets the sloping pelvic floor, causing the chin to contact the fetal thorax, producing a smaller diameter of presentation, changing from occipito-frontal to suboccipitobregmatic.
What is the significance of internal rotation during labor?
Internal rotation occurs as the head reaches the pelvic floor, where the occiput typically rotates anteriorly toward the pubic symphysis, allowing for proper alignment for delivery.
Explain the extension phase of labor.
During extension, the acutely flexed head descends, distending the pelvic floor and vulva. The base of the occiput encounters the inferior rami of the pubis, and the head extends until delivery, culminating in crowning.
What is restitution in the context of labor?
Restitution is the process following head delivery where the head rotates back to align with the fetal shoulders, indicating the occiput’s previous position before delivery.
What happens during the external rotation phase?
External rotation occurs as the shoulders reach the pelvic floor, rotating into the anteroposterior diameter, with the fetal head turning so that the face looks laterally at the maternal thigh.
Describe the delivery of the shoulders during labor.
The anterior shoulder is delivered first by applying posterior traction on the fetal head, followed by lifting the head anteriorly to deliver the posterior shoulder, leading to the expulsion of the trunk and lower limbs.
What marks the beginning and end of the third stage of labor?
The third stage begins with the expulsion of the baby and ends with the delivery of the placenta and membranes.
What signs indicate placental separation?
Signs include trickling of bright blood, lengthening of the umbilical cord, and elevation of the uterine fundus within the abdominal cavity.
Describe the changes in the uterine fundus after baby delivery.
After delivery, the uterine fundus becomes firm to hard, smaller, and rounded, sitting on top of the placenta instead of being broad and globular.
What occurs during the expulsion of the placenta?
The placenta is expelled alongside fetal membranes, which may become torn, necessitating additional traction using sponge forceps if required.
What is the typical duration of the third stage of labor?
The entire process lasts between 5-10 minutes, and if the placenta is not expelled within 30 minutes, it is diagnosed as retained placenta, making the third stage abnormal.
- When should a mother come into the hospital during labor?
A mother should come to the hospital when contractions are at regular 10-15 minute intervals, there is a show, or if the membranes rupture.
What general examinations should be performed at the commencement of labor?
A full general examination should include checking temperature, pulse, respiration, blood pressure, hydration state, and testing urine for glucose, ketones, and protein.
What are the components of an obstetrical examination of the abdomen?
The obstetrical examination includes inspection and palpation to determine fetal lie, presentation, position, and station of the presenting part. Fetal heartbeat is auscultated using a stethoscope or Doptone device.
What should be noted during a vaginal examination in labor?
Factors to note include:
Position, consistency, effacement, and dilatation of the cervix
Intact or ruptured membranes (color and quantity of amniotic fluid)
Fetal presentation and position (e.g., vertex, LOA)
Degree of caput, molding, and synclitism in vertex presentation
Assessment of the bony pelvis at upper, middle, and lower strait and pelvic outlet.
What are the general principles of managing the first stage of labor?
The general principles include:
Observation of labor progress and intervention if slow.
Monitoring fetal and maternal condition.
Providing pain relief and emotional support.
Ensuring adequate hydration and nutrition
What is a partogram and its purpose?
A partogram is a graphic record of labor progress, documenting cervical dilatation, contractions, fetal heart rate, color of liquor, caput, molding, station of the head, maternal heart rate, BP, and temperature, aiding in early recognition of non-progressive labor.
When should the partogram be started, and what is recorded as zero time?
The partogram should be started as soon as the mother is admitted to the hospital, with this admission time recorded as zero time, regardless of when contractions started.
How is fetal condition monitored during labor?
Fetal condition is monitored by charting fetal heart rate (FHR), noting any decelerations during contractions, recording the time of membrane rupture, and assessing the nature of the amniotic fluid (clear or meconium-stained).
What does the assessment of molding and caput indicate?
Molding and caput indicate potential obstructed labor. Molding is assessed by the degree of suture lines meeting, while caput is marked from + to +++, indicating the relative impression formed by the clinician.
What does it mean if molding is assessed as ++?
Molding assessed as ++ indicates that the sutures are overriding but reducible with gentle pressure, suggesting moderate molding of the fetal head.
How is progress in labor measured?
Progress in labor is measured by assessing the rate of cervical dilatation and descent of the presenting part, evaluated through vaginal examinations.
How often should vaginal examinations be performed during the first stage of labor?
Vaginal examinations should be performed on admission and every 3 to 4 hours thereafter during the first stage of labor.
What is the expected cervical dilation during the latent phase for multipara and nullipara?
In the latent phase, the cervix is expected to efface and dilate from 0 to 3 cm in 6 hours for multipara and in 8 hours for nullipara.
What is the expected rate of cervical dilation during the active phase of labor?
During the active phase, cervical dilation is expected at approximately 1 cm/hour from 3 cm to 10 cm for both multipara and nullipara, although multipara tend to dilate faster.
What are the alert and action lines in labor management?
The alert line represents expected progress at 1 cm/hour during the active phase. The action line, drawn 2 hours parallel to the alert line, indicates when to intervene if cervical dilation lags more than 2 hours behind.
How is the descent of the fetal head assessed during labor?
Descent is assessed by the palpable portion of the head above the pelvic brim in fifths and by measuring the level of the presenting part in cm relative to the ischial spines, marked as −1, −2, −3 (above) and +1, +2, +3 (below).
What do different shading patterns on the partogram represent?
Dotted squares indicate contractions of less than 20 seconds.
Cross-hatched squares represent contractions lasting between 20 and 40 seconds.
Complete shading indicates contractions lasting longer than 40 seconds.
Why should oral intake be avoided during the first stage of labor?
Oral intake should be avoided if operative delivery under general anesthesia is likely; most operative deliveries are now performed under regional anesthesia.
What should be considered regarding IV fluid replacement during labor?
IV fluid replacement should be considered after 6 hours in labor if delivery is not imminent. Normal saline or Hartmann’s solution is preferred, with careful monitoring of fluid input and output.
What major condition can arise from dehydration during labor?
Dehydration can lead to acidosis and ketosis, necessitating urine checks for ketones, sugars, and proteins.
What postures do women prefer during the different stages of labor?
Many women prefer to remain ambulant or sit during the first stage and may lie down as labor progresses to the second stage. Some may choose to squat to use gravity to assist in delivery.
What are the considerations for water births?
Water births can provide pain relief through immersion, improve support of the pregnant uterus, but carry risks of the baby inhaling contaminated water. Bath temperature should be regularly monitored.
- What is the primary goal of pain relief strategies in labor?
The primary goal is to reduce the level of pain experienced during labor while invoking minimal risk for the mother and baby.
Which pain relief technique provides complete pain relief during labor?
Epidural analgesia is the only technique that can provide complete pain relief.
What narcotic analgesics are commonly used in labor, and what are their side effects?
Pethidine was traditionally used but has been largely replaced by morphine.
Common side effects include nausea and vomiting in mothers and respiratory depression in neonates.
What is Remifentanil, and how does it compare to Pethidine?
Remifentanil is an ultra-short-acting opioid that produces superior analgesia compared to Pethidine and has less effect on neonatal respiration.
What is Entonox, and when is it used in labor?
Entonox is a 50/50 mixture of nitrous oxide and oxygen used for short-term pain relief in early labor and during the late first and second stages of labor.
What precautions should be taken when using nitrous oxide during labor?
Prolonged exposure can adversely affect birth attendants, causing decreased fertility, bone marrow changes, and neurological changes. Forced air change every 6–10 hours is necessary to reduce nitrous oxide levels.
What is Transcutaneous Electrical Nerve Stimulation (TENS), and when is it most effective?
TENS involves placing electrodes on the vertebral column to deliver electrical currents. It can be effective in early labor but is often inadequate alone in late labor. Antenatal training is essential for effectiveness.
What are some non-pharmacological methods of pain relief during labor?
Non-pharmacological methods include acupuncture, subcutaneous sterile water injections, massage, and relaxation techniques.
Describe how epidural analgesia is administered.
- Insert an intravenous cannula and preload with no more than 500 mL of saline or Hartmann’s solution.
- Insert the epidural cannula at the L3–L4 interspace.
- Inject a local anesthetic agent, such as bupivacaine, at the minimum dose required for effective pain relief.
What are the advantages of adding an opioid to a local anesthetic in epidural analgesia?
Adding an opioid reduces the required dose of bupivacaine, sparing motor fibers to the lower limbs and reducing the classic complications of hypotension and abnormal fetal heart rate.
What effects does epidural analgesia have on uterine activity during labor?
Epidural analgesia may reduce the desire to bear down in the second stage of labor due to decreased pressure sensation at the perineum and can decrease uterine activity by inhibiting the “Ferguson reflex.”
What are common complications of epidural analgesia?
Common complications include:
Hypotension
Accidental dural puncture (occurs in <1%)
Postdural headache (70% incidence with 16 or 18 gauge needles)
How can hypotension associated with epidural analgesia be managed?
Hypotension can be managed by preloading and using low-dose anesthetic agents and opioid solutions.
What should be done for a postdural headache that persists for more than 24 hours?
A postdural headache that persists for more than 24 hours should be treated with an epidural blood patch.
What are the contraindications to regional anesthesia?
Contraindications include:
Maternal refusal
Coagulopathy
Local or systemic infection
Uncorrected hypovolemia
Inadequate or inexperienced staff or facilities
What is spinal anesthesia, and when is it commonly used?
Spinal anesthesia is a single-shot procedure commonly used for operative delivery but not for pain control in labor.
Describe paracervical blockade and its risks.
Paracervical blockade involves the infiltration of local anesthetic agents into paracervical tissues. It is rarely used due to a greater chance of fetal side effects.
What is a pudendal nerve blockade?
Pudendal nerve blockade involves infiltration around the pudendal nerve and the inferior hemorrhoidal nerve. It’s less frequently used now but is still employed for perineal wound repair.
What precautions should be taken when using pudendal nerve blockade?
Avoid direct IV injection of the drug during local infiltration.
Be cautious of toxic symptoms like cardiac arrhythmias and convulsions from accidental injection, especially with larger doses.
- What changes in fetal heart rate may suggest fetal hypoxia?
Changes in fetal heart rate (FHR) or the passage of new meconium-stained liquor may indicate the possibility of fetal hypoxia.
What does a diminution of fetal movements (FM) on admission indicate?
A diminution of fetal movements may indicate fetal jeopardy, while cessation of movements may indicate fetal death.
How often is the fetal heart rate monitored during the first and second stages of labor?
First stage: Every 15 minutes for 1 minute after a contraction.
Second stage: Every 5 minutes or after every other contraction.
What are the specific indications for continuous electronic fetal monitoring?
Maternal indications:
Previous caesarean section
Pre-eclampsia
Post-term pregnancy
Fetal indications:
Fetal growth restriction
Prematurity
Oligohydramnios
Prolonged rupture of membranes
Induced labor
Diabetes
Antepartum hemorrhage
Other maternal medical diseases
Abnormal Doppler artery velocimetry
Multiple pregnancy
Meconium-stained liquor
Breech presentation
What is the normal range for fetal heart rate?
The normal fetal heart rate varies between 110 and 160 beats per minute.
What is fetal tachycardia and bradycardia?
Tachycardia: Fetal heart rate faster than 160 beats/min.
Bradycardia: Fetal heart rate less than 110 beats/min.
What does baseline variability in fetal heart rate indicate?
Baseline variability reflects the oscillations in heart rate around the baseline and normally varies between 5-25 beats/min. Reduced variability can indicate fetal sleep, hypoxia, infection, or medication effects.
What is considered abnormal baseline variability in fetal heart rate?
A fetal heart rate variability of less than 5 beats/min for over 90 minutes is abnormal and may indicate fetal jeopardy.
How is fetal heart rate typically monitored?
Fetal heart rate is monitored using a Doppler ultrasound transducer applied externally to the maternal abdomen or through a direct electrode applied to the presenting part.
What is the purpose of using a pressure transducer in fetal monitoring?
A pressure transducer records uterine activity, providing accurate measurements of the frequency and duration of contractions, and can also give relative information about intrauterine pressure.
What are accelerations in fetal heart rate?
Accelerations are transient, abrupt increases in heart rate of more than 15 beats/min for more than 15 seconds, associated with fetal movements.
They reflect the activity of the somatic nervous system and are a reassuring sign of good fetal health.
How are decelerations defined in fetal heart rate monitoring?
Decelerations are defined as decreases in heart rate of more than 15 beats/min for more than 15 seconds. They are evaluated based on their relationship to uterine contractions and their intensity.
What are early decelerations, and what do they indicate?
Early decelerations occur synchronously with uterine contractions, peaking at the contraction’s height, with a decrease in heart rate generally less than 40 beats/min. They are usually due to head compression and are considered physiological, often seen in the late first and second stages of labor.
Describe late decelerations and their significance.
Late decelerations begin well after the contraction starts and do not return to the normal baseline until at least 20 seconds after the contraction ends. They are due to placental insufficiency, and repeated occurrences may indicate fetal hypoxia, along with an increase in baseline rate and a reduction in baseline variability.
What are variable decelerations, and what do they suggest?
Variable decelerations vary in timing and amplitude, often falling by more than 40 beats/min, caused by cord compression.
They are considered non-reassuring features in a CTG trace, and increased depth and duration, along with a rise in baseline rate and reduced baseline variability, suggest worsening hypoxia.
What are atypical variable decelerations?
Atypical variable decelerations are characterized by slow recovery to baseline rates or a combination of variable decelerations followed immediately by late decelerations.
They are considered abnormal features and suggest a concerning fetal condition.
How is fetal blood obtained for acid-base balance assessment?
Fetal blood is obtained directly from the scalp through an amnioscope, which is inserted through the cervix (at least 2 cm dilated).
A small stab incision is made in the fetal scalp to collect blood into a heparinized capillary tube.
What position should the mother be in during fetal blood sampling?
The mother is requested to lie in the lateral position during the procedure for fetal blood sampling.
What is the normal pH range for fetal blood?
The normal pH for fetal blood lies between 7.25 and 7.35.
What does a pH between 7.20 and 7.25 indicate during the first stage of labor?
A pH between 7.20 and 7.25 indicates mild acidosis, and sampling should be repeated within the next 30 minutes.
What is recommended if the fetal blood pH is <7.20?
If the fetal blood pH is less than 7.20, delivery is recommended unless spontaneous delivery is imminent.
How can fetal acid-base balance also be assessed besides pH?
Fetal acid-base balance can also be assessed by measuring lactate levels in fetal scalp blood, which generally requires smaller blood volumes and can be done using portable hand-held devices.
- What is the definition of preterm birth?
Preterm birth is defined as delivery occurring from 24 completed weeks up to 36 weeks and 6 days of gestation.
What are some common aetiologies of spontaneous preterm labour?
Common aetiologies include poor social conditions, nutritional status, antepartum hemorrhage, multiple pregnancy, uterine anomalies, cervical incompetence, and preterm premature rupture of membranes (PROM), often associated with infection.
What is the best single predictor of spontaneous preterm delivery?
A previous history of preterm delivery is the best single predictor of spontaneous preterm labour.
How do genital tract infections contribute to preterm labour?
Genital tract infections can promote myometrial activity or cause prelabour rupture of fetal membranes.
Associated organisms include Neisseria gonorrhoeae, group B streptococci, Chlamydia trachomatis, Gardnerella vaginalis, Bacteroides spp., and Haemophilus spp.
What is the impact of delaying delivery after 24 weeks on infant survival?
Each day of delay in delivery after 24 weeks increases the chance of survival by 3–6%.
What is the survival likelihood of an infant based on birth weight?
Infants born with a birth weight of less than 500 g have little chance of survival, whereas those weighing 1500 g are nearly as likely to survive as full-term infants.
Survival significantly increases with every 100 g increment between 500 and 1000 g.
What are the major causes of death in very-low-birth-weight infants?
Major causes of death include infection, respiratory distress syndrome, necrotizing enterocolitis, and periventricular hemorrhage.
What are some immediate complications of preterm birth?
Immediate complications include respiratory distress, jaundice, hypoglycemia, and hypothermia.
What are some long-term complications associated with preterm birth?
Long-term complications can include pulmonary dysplasia and neurodevelopmental delay.
What is a primary goal in the management of preterm labour?
A primary goal is to conserve the pregnancy for as long as possible to improve infant outcomes and survival.
What lifestyle and dietary advice should be given to women with a history of preterm labor?
Women should be advised to maintain a healthy lifestyle, including proper nutrition, stress avoidance, and regular prenatal care.
How can the treatment of asymptomatic bacteriuria affect preterm labor?
Treating asymptomatic bacteriuria with antibiotics can reduce the incidence of preterm premature rupture of membranes (PROM), especially when β-haemolytic streptococci are detected.
What is the role of progesterone in women with a short cervix during pregnancy?
In women with a short cervix of less than 2.5 cm beyond 24 weeks, the use of progesterone can reduce the incidence of preterm delivery.
What is the goal of administering corticosteroids in preterm labor management?
The administration of corticosteroids aims to enhance fetal lung surfactant production, reducing the risk of hyaline membrane disease (HMD) and respiratory distress syndrome (RDS).
Under what conditions might labor be inhibited rather than allowed to proceed?
Labor may be inhibited if gestational age is less than 34 weeks, there are no signs of infection or bleeding, membranes are intact, and the cervix is less than 5 cm dilated.
Prolonged Third Stage of Labour
Cord presentation, cord prolapse
- Definition
- Causes, risk factors
- Clinical features
- Diagnosis
- Treatment
Contradiction for instrumental delivery
Obstetric forceps delivery
Vacuum extractor delivery
Procedure for Cesarean
Types of incisions
- Definition
- Advantages
- Disadvantages
