Operative Obstetrics, Substance Abuse, Teratogens

C-Section

The abdominal delivery of a baby

Frequency has increased over time

• Physician fear of malpractice lawsuits

• Increase for first time mothers

• Introduction of electronic fetal monitoring, decrease in operative vaginal deliveries, and attempts at vaginal breech deliveries

Has been slight increase in TOLACs (trial of labor after cesarean)

Indications for C-section

Performed when vaginal delivery would pose greater risk to mother or fetus

• Labor related (MC) – failure to progress or fetal distress

• Malpresentation – breech, transverse or oblique lie, face/brow presentation (persistent)

• Placental indications – placenta previa, vasa previa, placenta accreta spectrum, severe placental abruption

• Prior uterine surgery – prior classical (vertical) C-section, prior uterine rupture, extensive trans-fundal surgery, multiple prior C-sections

• Maternal indications – active genital herpes lesions, certain pelvic structural abnormalities, severe cardiac disease, certain neurological conditions (brain aneurysm at risk of rupture), severe preeclampsia with unfavorable cervix

• Infectious indications – active HSV lesions, HIV with high viral load (>1000 copies/mL), certain cases of primary CMV or varicella near delivery

• Multiple gestation – twin A not vertex, mono-amniotic twins, high-order multiples

• Fetal indications – suspected macrosomia, severe fetal growth restriction with abnormal dopplers, certain fetal anomalies

• Emergent indications – uterine rupture, cord prolapse, severe abruption with instability, failed operative vaginal delivery

Spinal Anesthesia

• A single injection of local anesthetic (± opioid) into the subarachnoid space (CSF) at L3-L4 or L4-L5

  • Used for scheduled C-sections

• Benefits

  • Onset is very rapid (5-10 min)

  • Minimal fetal exposure

  • Limited duration (~1.5-3 hrs)

• Risks

  • Possible hypotension

  • Post-dural puncture headache

Epidural Anesthesia

• Typically used for vaginal birth

• Catheter placed into the epidural space and medication infused continuously

  • Labor epidural that is “topped up” for C-section

• Slower onset (10-20 min)

• Adjustable dosing, can extend duration

• Lower hypotension risk compared to spinal

• May fail → need to convert to general anesthesia

Spinal vs Epidural

General Anesthesia

• IV induction, endotracheal intubation, inhaled anesthetic maintenance

General Anesthesia Indications

• True emergency (ex: uterine rupture, cord prolapse)

• Crash C-section

• Neuraxial contraindicated

• Failed spinal/epidural

• Patient refusal

• Coagulopathy

• Severe thrombocytopenia

General Anesthesia Disadvantages

• Higher maternal morbidity and mortality

• Risk of aspiration (pregnancy = full stomach)

• Difficult airway risk (edematous airway)

• Neonatal respiratory depression (if prolonged induction)

• Patient not awake for birth

Neuraxial Anesthesia

• Spinal and epidurals are both considered neuraxial

  • Neru. → nerve/nervous system

  • Axial → axis (central line of the body)

• Neuraxial anesthesia refers to anesthesia delivered along the central nervous system axis

Neuraxial Anesthesia Contraindications

• Platelets <70-80k

• Coagulopathy

• Infection at insertion site

• Severe hypovolemia

• Patient refusal

• Increased intracranial pressure

Neuraxial Anesthesia and Platelets

• During neuraxial placement (spinal or epidural), a needle passes through tissues → small blood vessels can be injured and normally bleeding stops quickly

  • Platelets are essential for clot formation

  • If platelets are low → bleeding may not stop and blood can accumulate in the epidural or spinal space → forms a spinal epidural hematoma which can compress the spinal cord and cause paralysis

  • You cannot see bleeding in epidural space and symptoms may not appear immediately

• If platelets <70,000 → neuraxial anesthesia is avoided and general anesthesia is used

• HELLP syndrome → more caution because platelets are dropping rapidly

C-Section Step 1: Preparation

• Confirm indication

• Fetal heart check

• Consent

• IV access

• Type & screen

• Antibiotics (cefazolin before incision)

• Sequential compression devices

• Foley catheter

• Neuraxial anesthesia

C-Section Step 2: Skin Incision

• Most commonly Pfannensxiel incision → curved transverse incision 2-3 cm above pubic symphysis, through the skin and subcutaneous tissue

C-Section Step 3: Open Fascia

• Incise anterior rectus sheath transversely

• Extend laterally

• Separate fascia from rectus muscles

C-Section Step 4: separate rectus muscles

• Rectus muscles separated in midline

• Enter peritoneum carefully (bladder could be there)

• Extend peritoneal opening

• Now the abdomen is entered

C-Section Step 5: expose the uterus

• Identify the lower uterine segment

• Bladder blade is inserted

  • Create bladder flap (depends on surgeon)

  • Incise vesicouterine peritoneum

  • Push bladder down

C-Section Step 6: uterine incision (hysterotomy)

• Low transverse uterine incision

  • Small transverse incision in lower uterine segment

  • Do very slowly

  • Extend bluntly with fingers or scissors

C-Section Step 7: deliver the baby

• Rupture membranes (if intact)

• Deliver fetal head

• Gentle but firm fundal pressure

• Suction mouth/nose if needed

• Clamp and cut cord

• Neonatal team received baby

• Time from incision to delivery ideally <5 minutes

Uterine Window

• Refers to marked thinning of a prior uterine scar where the myometrium is so thin that the fetal membranes or even the fetus can be seen through it but the uterus has not fully ruptured

• Extremely thin lower uterine segment

• Weak prior scar and increased risk of uterine rupture in future pregnancies

• Usually recommended to not get pregnant again

C-Section Step 8: deliver the placenta

• Gentle and controlled cord traction

• Uterine massage

• Oxytocin started (especially if boggy uterus)

C-Section Step 9: inspect the uterus

• Check cavity for retained tissue

• Clear clots

• Assess incision edges

C-Section Step 10: close the uterus

• Usually 1-2 layer closure

  • Absorbable suture

  • Ensure hemostasis

C-Section Step 11: close the abdomen

• Return uterus into abdomen (lots of pressure for the patient)

• Irrigate

• Close fascia (most important layer)

• Re-approximate subcutaneous tissue (if thick)

• Close skin (sutures, staples, or glue)

C-section Incision Layers

Common C-section Intra-op Complications

• Uterine incision extension

• Bladder injury

• Postpartum hemorrhage

• Adhesions (repeat cases)

• Bowel injury (rare)

Effects of C-section for Newborn

• Immediate effects

  • Respiratory distress (MC)

    • During vaginal birth the uterine contractions help squeeze fluid from fetal lungs; catecholamine surge helps clear lung fluid

    • In C-section there is no “thoracic squeeze” → less catecholamine surge; delayed lung fluid clearance

    • This results in transient tachypnea of the newborn (TTN)

    • Rapid breathing, mild oxygen need, usually resolves in 24-72 hours

    • More common if elective C-section before 39 weeks and no labor prior to surgery

  • Lower initial breastfeeding rates

    • Possibly due to delayed skin-to-skin, maternal pain/recovery, separation in the OR, effects of anesthesia

  • Microbiome & immune effects

    • Babies born vaginally are exposed to maternal vaginal and gut flora

    • C-section babies are exposed more to skin and hospital flora

    • Research shows differences in early gut microbiome composition, and some studies suggest small associations with: higher rates of asthma, allergies, T1 DM, obesity

    • Breastfeeding helps normalize microbiome differences

Positive Effects of C-section for Newborn

• Prevents hypoxic injury in fetal distress

• Prevents trauma in breech birth

• Prevents birth injuries

• Reduces vertical HSV transmission

• Reduces HIV transmission (if high viral load)

• In many cases, it is lifesaving

TOLAC vs VBAC

• TOLAC = trial of labor after Cesarean section

  • TOLAC is an attempt at vaginal delivery: the goal is to achieve VBAC but still may result in another C-section if labor fails (failed TOLAC ending in repeat C-section usually has more complications)

  • Higher likelihood if prior vaginal delivery has occurred

  • Lower likelihood if labor is induced or augmentation is required

  • Women who had C-section for breech are more successful with TOLAC than women who had C-section for arrest of labor

• VBAC = vaginal birth after Cesarean section

  • Not all TOLACs will end up with VBACs, it is just a trial and may end up in a C-section regardless

  • Best case scenario and elective repeat C-section is the next best scenario

• As TOLACs increased over time, so did reports of uterine rupture and other complications → increased liability → reversed to higher C-section rates → needs to be risk/benefit conversation with patient

TOLAC Candidates

• High VBAC success rates and low rupture risk

• Candidates:

  • One prior low transverse C-section (best candidate)

  • Prior vaginal delivery (strong predictor of success)

  • Vaginal birth before or after C-section

  • Spontaneous labor

  • Nonrecurring indication for prior C-section

    • Ex: breech, fetal distress, placenta previa

  • Adequate pelvis/average fetal size

  • Institution capable of emergency C-section

TOLAC Contraindications

• Prior classical (vertical) uterine incision

  • High rupture risk

• Prior uterine rupture

  • High recurrence risk

• Prior T-incision or J incision (incisions on uterus)

• Extensive trans-fundal uterine surgery

  • Myomectomy entering cavity

  • Deep uterine construction

• Contraindications to vaginal delivery

  • Placenta previa, vasa previa, transverse lie, active HSV lesions

TOLAC Relative Contraindications

• Lower success rate

  • Multiple prior C-sections (2+)

  • Suspected macrosomia (>4500 g)

  • Obesity

  • Induction of labor

  • Prior arrest of descent

  • Short inter-pregnancy interval (<18 mo)

TOLAC Procedure

• Oxytocin and epidural are acceptable

• NOT safe to use prostaglandins for cervical ripening (ex: misoprostol, cervidil)

  • Increased risk of uterine rupture

Operative Vaginal Delivery

• Assisted vaginal birth using forceps or vacuum to expedite delivery of the fetal head

• Used when vaginal delivery is possible but needs assistance

• Types:

  • Vacuum extraction

  • Forceps delivery

Vacuum Extraction

• Soft or rigid suction cup applied to fetal scalp → negative pressure created → traction applied during contractions

Forceps Delivery

• Two metal blades placed around fetal head → traction applied

  • Can also rotate fetal head

  • Used less commonly

Indications for Operative Delivery

• Prolonged second stage of labor

• Non-reassuring fetal heart tracing

• When delivery is needed quickly

• Maternal exhaustion

• Maternal medical conditions when pushing should be limited

  • Cardiac disease

  • Severe preeclampsia

  • Certain neurologic conditions

Prerequisites for Operative Delivery

• All MUST be present

  • Full cervical dilation

  • Ruptured membranes

  • Known fetal position

  • Fetal head engaged (+2 station)

  • No suspicion of cephalopelvic disproportion

  • Adequate anesthesia

  • Empty bladder

  • Informed consent

  • Ability to proceed to emergency C-section if needed

Operative Delivery Maternal Complications

• Perineal lacerations (higher risk with forceps)

• Vaginal tears

• Postpartum hemorrhage

• Pelvic floor injury

• Neonatal

Operative Delivery Fetal Complications

• Vacuum

  • Scalp lacerations

  • Cephalohematoma

  • Subgaleal hemorrhage (rare but serious)

  • Jaundice

• Forceps

  • Facial nerve palsy

  • Skull fractures (rare)

  • Ocular injury (rare)

Intrauterine Fetal Demise

• ACOG defines fetal demise as a fetus that dies in the uterus

  • Used in clinical and diagnostic settings before delivery

  • Describes the clinical event of fetal death before delivery

  • Does not specify gestational age

Intrauterine Stillbirth

• ACOG defines stillbirth as the delivery of a fetus that shows no signs of life

  • Used after delivery when the fetus is born without life

  • After 20 weeks gestation

  • Used more as a vital statistics/public health term

Stillbirth Causes

• Most common is placental insufficiency/placental dysfunction

• 20-40% remain unexplained

• Maternal → hypertension, preeclampsia, diabetes, thrombophilias, lupus

• Infection → listeria, syphilis, parvovirus B19, CMV, chorioamnionitis

• Fetal → genetic abnormalities, congenital malformations, severe growth restriction

• Umbilical cord events → true knot, prolapse, hyper-coiling

Stillbirth Evaluation

• Review genetic, medical and obstetric history

• Determine if consanguinity

• Encourage autopsy

• Photos of fetus and any abnormalities

• Full-body skeletal x-rays

• Full-body MRI

• Look for dysmorphic features

• Obtain cord blood for chromosomal DNA analysis

• Obtain fetal serum for infectious disease studies

• Obtain fetal tissue sample for cell culture

• Obtain parental bloods for chromosome analysis

• Communicate final autopsy results

• Provide follow-up counseling

Induced Abortion

• The termination of a pregnancy medically or operatively before fetal viability (definition of viability varies from state to state)

  • Elective voluntary – interruption of pregnancy at the request of the mother

  • Therapeutic – interruption of pregnancy for the purpose of safeguarding the health of the mother or fetus incompatible with life

• Performed first and second trimester

  • Must be aware of state laws

• Techniques

  • Mechanical

  • D & E: suction or curettage

  • Medical – up to 9 weeks (varies, but the larger the size the more pain and cramping and possibility for incomplete abortion)

• Pre-abortion work up

  • U/S – assure dates correspond with uterine size

  • Labs – ABO/Rh typing

  • Administer Rhogam in Rh (-) moms

  • Careful patient counseling should be performed

Medication Induced Abortion

• Early pregnancy, approved up to 10 weeks gestation

• Mifepristone + Misoprostol (gold standard)

  • Mifepristone 200 mg PO followed 24-48 hours later by misoprostol 800 mcg buccal, vaginal, or sublingual

  • Causes decidual breakdown, uterine contractions, cervical softening

• Expected symptoms

  • Cramping

  • Heavy bleeding

  • Passage of clots

  • Nausea

  • Fever

  • Diarrhea

• Misoprostol-only regimen (when mifepristone is unavailable)

  • 800 mcg vaginal/buccal repeated every 3-4 hours (up to 3-4 doses)

  • Slightly lower efficacy than combination

  • Prescribers must complete a one-time prescriber agreement form under the REMS program (Risk Evaluation and Mitigation Strategy)

  • Some states restrict or ban prescribing mifepristone

  • Need to follow up to confirm termination with bHCG and vaginal US

Medication Induced Abortion Contraindications

• Confirmed or suspected ectopic pregnancy

• Chronic steroid use (mifepristone blocks glucocorticoid receptors)

  • Could maybe use misoprostol only regimen

• Bleeding disorder

• Anticoagulation

• IUD in place (must remove first)

Surgical Induced Abortion

• Vacuum aspiration (manual or electric) up to 14-16 weeks

  • Cervical dilation and then suction device removes products of conception

  • Takes 5-10 minutes

  • Have local anesthesia with possible sedation

• Dilation and evacuation (D&E)

  • Cervical preparation (misoprostol or osmotic dilators) and instrumental removal of fetal and placental tissue

  • Done in second trimester (14-24 weeks)

Complications of Induced Abortion

• Hemorrhage

• Infection

• Retained tissue

• Ongoing pregnancy

• Uterine perforation (procedural)

• Asherman syndrome (rare: scar tissue forms in uterus)

Therapeutic Induced Abortion

• Pregnancy significantly endangers maternal life or major organ function

• Therapeutic abortion ≠ elective abortion

Therapeutic Induced Abortion: Maternal Indications

• Severe maternal medical disease

  • Severe cardiac disease (ex: pulmonary HTN)

  • Advanced cardiomyopathy

  • Severe renal failure

  • Severe pulmonary disease

  • Certain cancers requiring urgent treatment

  • Uncontrolled severe autoimmune disease

• Life-threatening obstetric complications → pre-viable

  • Severe preeclampsia

  • HELLP syndrome

  • Placental abruption

  • Chorioamnionitis

  • PPROM with infection

  • Uterine rupture

  • Uncontrolled hemorrhage

• Psychiatric conditions

  • Severe psychiatric illness with high risk of self-harm

  • Suicidal ideation directly related to pregnancy

Therapeutic Induced Abortion: Fetal Indications

• Lethal fetal anomalies

  • Anencephaly

  • Bilateral renal agenesis

  • Severe skeletal dysplasia incompatible with life

  • Certain lethal genetic syndromes

  • Severe hydrops fetalis with poor prognosis

• Severe chromosomal abnormalities → trisomy 13, trisomy 18, certain triploidy cases

• Severe early growth restriction with non-viability

• Rape or incest (depending on legal/ethical frameworks)

Substance Abuse in Pregnancy

• A medical condition, not a moral issue

• Pregnancy is a critical opportunity for treatment

• Substance use includes:

  • Tobacco

  • Alcohol

  • Opioids (heroin, prescription opioids, fentanyl)

  • Cocaine

  • Methamphetamine

  • Cannabis

  • Benzodiazepines

  • Poly-substance use (very common)

Substance Abuse in Pregnancy Maternal Risks

• Poor prenatal care

• Malnutrition

• Intimate partner violence (IPV)

• Infections (HIV, hepatitis C)

• Placental abruption (especially cocaine)

• Preterm labor

• Overdose (leading cause of maternal mortality in some states)

Substance Abuse in Pregnancy Screening

• UNIVERSALLY SCREEN

• Urine toxicology should be consented

  • Not required

• Be aware of the laws in your state

Substance Abuse in Pregnancy Management

• Do NOT abruptly stop certain substances without supervision

• Social work involvement

• Mental health care

Teratology

• The study of abnormal development and congenital malformations (birth defects) and the agents that cause them

• Teratogen is any agent that can cause abnormal fetal development

  • Ex: smoking, alcohol, drugs, medications, infections, radiation, hyperthermia

• Effect depends on timing, dose, route, and length of teratogen

• Timing

  • “All-or-none” exposure in weeks 0-2: either have pregnancy loss or no effect at all

  • Most sensitive during organogenesis → weeks 3-8 (when we start to be worried about malformations)

• Dose matters (higher dose = higher risk)

• Chronic exposure → more severe effects

• Genetic susceptibility matters

• Some organs are more vulnerable than others

Tobacco and Pregnancy

• Most common

• Pathophysiology

  • Nicotine → vasoconstriction → placental insufficiency

  • Carbon monoxide replaces oxygen in the blood, leading to fetal hypoxia

• Fetal/newborn effects

  • IUGR

  • Low birth weight

  • Placental abruption

  • Preterm birth

  • Stillbirth

  • SIDS

• Quitting in the 1^st trimester reduces the risk of low birth weight to nearly that of a non-smoker

• Stopping at any state of pregnancy improves oxygen delivery, increases fetal growth, and reduces complications

• Management

  • Behavioral counseling

  • Nicotine replacement therapy

Alcohol and Pregnancy

• Pathophysiology

  • ETOH crosses placenta: fetal blood ETOH ~ maternal ETOH

• Fetal alcohol spectrum disorder (FASD)

  • No known amount where you could get it or you could not

  • Facial anomalies

  • Growth restriction

  • Microcephaly

  • Intellectual disability

  • Behavioral problems

• One of the most common preventable causes of birth defects and childhood disabilities

• Management

  • Behavioral therapy

  • Inpatient detox if severe dependence

• Breastfeeding:

  • Avoid heavy use

  • Recommended to wait 3-4 hours after a single drink before breastfeeding

  • If ”buzzed”: alcohol is in the breastmilk

Cannabis

• Data is evolving on this

• Can actually worsen nausea

• THC crosses placenta and enters the fetal bloodstream → binds to cannabinoid receptors in the fetal brain which are critical for neural growth & brain development

• Not associated with major structural anomalies

• Associated with

  • Lower birth weight

  • Neurodevelopmental concerns

  • Attention problems

• Breastfeeding discouraged

  • THC is stored in fat and remains in breast milk for days to weeks after use, which can cause delayed motor development for the infant

Opioids

• Heroin, Oxycodone, Fentanyl

  • Cross the placenta and enter the fetal bloodstream

  • Risks during pregnancy

    • Preterm birth

    • IUGR

    • Stillbirth (if overdose)

• Neonatal abstinence syndrome (NAS)

  • Withdrawal symptoms after birth (irritability, high-pitch cry, tremors, poor feeding, diarrhea)

• Preferred treatment: medication-assisted treatment (MAT)

  • Methadone

  • Buprenorphine

  • Do NOT detox abruptly → increases relapse and overdose risk

• Breastfeeding reduces NAS severity in opioid-exposed infants

  • Breastfeeding encouraged if mom is on methadone or buprenorphine and not using illicit opioids

Cocaine

• Intense vasoconstriction

• Crosses the placenta and fetal blood-brain barrier

• Risks

  • Placental abruption

  • Preterm birth

  • Stroke

  • IUGR

  • Cocaine overdose is a medical emergency

    • Ice baths, cooling blanket, sedation with a benzodiazepine and BP control (avoid beta blockers: may worsen hTN by causing unopposed alpha-adrenergic vasoconstriction)

• Breastfeeding contraindicated if actively using – major cardiovascular changes in neonates

Methamphetamine

• Similar to cocaine risks: growth restriction, preterm birth, neurodevelopmental concerns

• Breastfeeding contraindicated if actively using

Benzodiazepines

• Possible neonatal withdrawal

• Floppy infant syndrome (rare)

• Sedation

Teratogenic Medications

• Retinoids vitamin A derivatives (Accutane) → absolute contraindication

  • Can cause cleft palate, microtia/anotia, cardiac defects, CNS abnormalities, thymic hypoplasia

  • Patients on Accutane need to sign up for iPLEDGE program

• Anti-epileptics (Valproate, Carbamazepine)

  • Neural tube defects

  • Use lowest effective dose and take folic acid 4mg daily

• Antibiotics

  • Tetracyclines → permanent tooth discoloration and bone growth inhibition

  • Fluoroquinolone → cartilage toxicity

  • Trimethoprim → neural tube defects in 1^st trimester

  • Sulfonamides (near term) → displaces bilirubin from albumin which can cause increased risk of kernicterus

  • Aminoglycosides → ototoxicity

  • Chloramphenicol → gray baby syndrome

  • Nitrofurantoin → avoid near term due to risk of hemolysis in G6PD deficiency

• Warfarin → use heparin in pregnancy

• ACE inhibitors (specifically 2^nd/3^rd trimester)

• Infections (TORCH)

• Radiation → high dose exposure causes microcephaly and intellectual disability

• Chemotherapy dependent on gestational age

  • Methotrexate contraindicated → folate antagonist, causes severe malformations

• Psychiatric medications

  • Paroxetine (Paxil) → slight increased risk of cardiac defects in 1^st trimester

  • Lithium → Ebstein anomaly (cardiac anomaly)