Can a clinically euthyroid pregnant woman in mid‑gestation with suppressed thyroid‑stimulating hormone (TSH), low free triiodothyronine (free T3), normal free thyroxine (free T4), and no comorbidities such as cardiovascular disease, uncontrolled hypertension, or active infection be cleared for a medically indicated cesarean section?

Can This Patient Be Cleared for Cesarean Section?

Yes, a clinically euthyroid pregnant woman in mid-gestation with suppressed TSH, low free T3, normal free T4, and no cardiovascular disease, uncontrolled hypertension, or active infection can be safely cleared for medically indicated cesarean section. This thyroid profile does not represent a contraindication to surgery.

Thyroid Status and Surgical Clearance

The described thyroid profile does not preclude cesarean section. The patient is clinically euthyroid with normal free T4, which is the primary determinant of thyroid function during pregnancy 1. The suppressed TSH with low free T3 but normal free T4 may represent a variant of normal pregnancy physiology or mild non-thyroidal illness, neither of which contraindicate surgery 1.

• Thyroid hormone supplementation is not indicated for euthyroid patients undergoing surgery, even with abnormal laboratory values, as there is no evidence of improved outcomes except in documented hypothyroidism 1
• The cardiovascular system tolerates cesarean section well in euthyroid patients, as thyroid hormone's primary effects on cardiac inotropy, heart rate, and peripheral vascular resistance are maintained with normal free T4 levels 1

Pre-operative Preparation Requirements

Standard cesarean section preparation should proceed without thyroid-specific modifications:

• Administer intravenous first-generation cephalosporin within 60 minutes before skin incision 2
• Add azithromycin if the patient is in labor or membranes are ruptured 2
• Use chlorhexidine-alcohol solution for abdominal skin preparation 2
• Apply povidone-iodine vaginal preparation 2
• Position the patient with left uterine displacement after 20 weeks gestation to prevent aortocaval compression 3, 2

Anesthetic Considerations

Regional anesthesia is strongly preferred and safe in this patient:

• Spinal or epidural anesthesia should be used rather than general anesthesia 3, 2
• Intrathecal morphine 50-100 µg (or diamorphine up to 300 µg) provides optimal postoperative analgesia 2
• Pre-operative oral paracetamol should be administered 2
• The patient's euthyroid status ensures normal cardiovascular response to regional anesthesia 1

Intraoperative Management

Maintain adequate maternal oxygenation and optimize uteroplacental perfusion throughout the procedure 2:

• Apply forced-air warming devices, warm intravenous fluids, and raise operating room temperature to prevent hypothermia 2
• Monitor maternal oxygen saturation and ensure adequate oxygenation 3
• Use Joel-Cohen (modified Misgav-Ladach) transverse abdominal incision to reduce postoperative pain 2
• Expand the transverse uterine hysterotomy bluntly 2

Critical Pitfalls to Avoid

Do not delay surgery based solely on abnormal thyroid function tests in a clinically euthyroid patient. The suppressed TSH with low free T3 but normal free T4 does not represent a surgical contraindication and does not require correction before proceeding 1.

• Avoid general anesthesia unless absolutely necessary, as regional anesthesia is safer and allows better maternal-fetal monitoring 3, 2
• Do not withhold standard antibiotic prophylaxis—administer within 60 minutes before incision, not after cord clamping 2
• Ensure left uterine displacement is maintained throughout the procedure to prevent aortocaval compression 3, 2

Absolute Contraindications Not Present

This patient lacks the cardiac and vascular conditions that would mandate special cesarean section considerations:

• No severe pulmonary hypertension (which would require cesarean section) 3, 4
• No significant aortopathy (aortic diameter >45 mm in Marfan syndrome or >40 mm in other conditions) 3, 4
• No acute maternal cardiac instability or heart failure 3, 4
• No ongoing anticoagulation therapy requiring special timing considerations 3