Maternal complications during pregnancy

Supine hypotensive syndrome

• Compression of the vena cava and pelvic veins by the uterus may occur during the third trimester of pregnancy (typically >20 weeks) as a result of the mother lying in a supine position.
  • Gravid uterus → compression of the abdominal aorta and IVC → impaired venous return and decrease in cardiac output → placental hypoperfusion → fetal hypoxia → deceleration (CTG)
  • After repositioning the mother in the left lateral position, the fetal heart rate recovers.
  • In the mother, supine hypotensive syndrome is characterized by tachycardia, dizziness, and nausea, and occasionally causes syncope.

Cervical insufficiency

• Definition & Risk Factors
  • Structural cervical weakness causing painless 2nd-trimester loss (16–24 wks GA).
  • Risks: Prior LEEP/CKC (conization), mechanical cervical dilation (D&C/D&E), prior 2nd-trimester loss, uterine anomalies, DES exposure.
• Clinical Features
  • Painless cervical dilation/effacement in the 2nd trimester without contractions.
  • Mild pelvic pressure or increased mucoid/watery vaginal discharge.
  • PE: Dilated cervix with bulging / “hourglass” membranes prolapsing into the vagina. c
• Diagnosis
  • Initial / Screening: TVUS showing cervical length (CL) < 25 mm prior to 24 wks GA.
  • Ultrasound sign: Cervical funneling (T $\to$ Y $\to$ V $\to$ U-shape).
  • Gold Standard / Clinical: History of $\ge 2$ consecutive painless 2nd-trimester losses OR painless dilation on exam.
• Management Algorithm
  • Incidental Short Cervix (CL $\le 20\text{–}25\text{ mm}$) + NO prior PTB:
    • Vaginal progesterone daily until 36–37 wks (cerclage is not indicated).
  • Prior sPTB / 2nd-Trimester Loss:
    • Serial TVUS CL monitoring every 1–2 wks from 16 to 24 wks GA.
    • If CL < 25 mm before 24 wks: Place Cervical Cerclage + progesterone.
  • History-Indicated Cerclage:
    • Elective placement at 12–14 wks GA for pts with $\ge 2$ prior 2nd-trimester losses.
  • Cerclage Removal:
    • Electively at 36–37 wks GA for planned vaginal delivery.
    • Urgent removal: Remove immediately if active labor or PPROM develops to avoid cervical laceration/uterine rupture.
• Complications
  • PPROM and extreme preterm birth (PTB).
  • Chorioamnionitis / intra-amniotic infection.
  • Cervical laceration if labor begins with cerclage in place.

Pregnancy dermatoses

Quick Rule-Out Algorithm

• No primary rash + itchy palms/soles $\to$ Intrahepatic Cholestasis (ICP) (check TBA).
• Striae rash + SPARES umbilicus $\to$ Pruritic Urticarial Papules and Plaques of Pregnancy (PUPPP) (topical steroids; safe). c
  • Also known as Polymorphic Eruption of Pregnancy
  • Pathophysiology: Abdominal wall distension/stretching damaging connective tissue, triggering an inflammatory reaction.
• Vesicles/bullae + INVOLVES umbilicus $\to$ Pemphigoid Gestationis (autoimmune; DIF positive; fetal risk).
• Flexural rash + 1st/2nd trimester $\to$ Atopic Eruption of Pregnancy (safe).
• Sterile pustules + fever/hypocalcemia $\to$ Pustular Psoriasis (systemic steroids).

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Comparison Matrix

Condition	Timing	Key Features	Diagnosis	Treatment	Fetal Risk
Intrahepatic Cholestasis (ICP)	Late 2nd/3rd Tri	Pruritus on palms & soles; NO primary rash (excoriations only)	Serum Bile Acids (TBA) $\ge$ 10 $\mu \text{mol/L}$; ↑ LFTs	UDCA + Deliver at 36–39 wks ($\ge$100 $\mu \text{mol/L}$ $\to$ deliver at 36 wks)	High (IUFD, preterm birth, meconium)
PUPPP	Late 3rd Tri / Postpartum	Pruritic papules in abdominal striae; SPARES umbilicus	Clinical (DIF negative)	Topical steroids + antihistamines	None
Pemphigoid Gestationis (PG)	2nd/3rd Tri	Pruritic plaques $\to$ tense bullae; INVOLVES umbilicus	Biopsy + DIF: Linear C3 & IgG at BMZ	Oral/systemic corticosteroids	Yes (FGR, preterm birth, transient neonatal rash)
Atopic Eruption (AEP)	1st/2nd Tri (Earliest)	Eczematous rash on flexural areas; prior atopy history	Clinical; ± ↑ IgE	Emollients + topical steroids	None
Pustular Psoriasis (PPP)	3rd Tri	Sterile pustules in flexures; fever, leukocytosis, hypocalcemia	Sterile pustule culture + Biopsy (spongiform pustules)	Systemic corticosteroids or Cyclosporine	Yes (Placental insufficiency, IUFD)

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Step 2 CK “Must-Know” Distinctions

1. ICP Delivery Timing:
   • TBA 10–99 $\mu \text{mol/L}$: Deliver at 36 0/7 – 39 0/7 wks.
   • TBA $\ge$ 100 $\mu \text{mol/L}$: Deliver at 36 0/7 wks.
2. Umbilicus Rule:
   • PUPPP: Periumbilical halo spared.
   • Pemphigoid Gestationis: Periumbilical skin affected first.
3. Fetal Risk:
   • Fetal Danger: ICP, Pemphigoid Gestationis, Pustular Psoriasis.
   • Benign for Fetus: PUPPP, AEP.