WEEK 6Trimester 1•Baby: Sweet pea / Lentil
Primitive Cardiac Tube & Neural Tube Closure
Estimated Length0.5 cm
Estimated Weight0.2 g
Fetal Morphogenesis & Anatomy Highlights
- •Primitive tubular heart begins rhythmic contractions (100–115 bpm), detectable on transvaginal ultrasound (TVUS).
- •Cranial and caudal neuropores close; neural tube formation completes.
- •Limb buds appear as subtle paddle-shaped swellings.
- •Early facial development begins with optic pits and primitive pharyngeal arches.
Same-Day Assessment / Urgent Care
Week 6 Urgent Red Flags
Immediate clinical evaluation or presentation to Winnipeg Obstetric Triage (HSC / St. Boniface) is indicated if:
- •Inability to keep liquids down for > 12-24 hours with ketonuria, postural dizziness (hyperemesis gravidarum)
- •Unilateral pelvic pain with or without spotting
- •Fever > 38.5°C
Women's Hospital HSC Triage: 204-787-8600 | St. Boniface: 204-237-2263
Clinician Perspective • Physiological & Screening Protocols
Maternal Physiological Adaptations
hCG doubling time is roughly 48 hours. Progesterone-induced smooth muscle relaxation slows gastrointestinal transit time.
Expected Clinical Symptoms
Nausea with or without vomiting (morning sickness)Heightened olfactory sensitivityFrequent urinationProfound fatigue
Clinical Investigations & Screening Schedule
- ✓Early dating ultrasound indicated if irregular cycles, unsure LMP, or spotting (Crown-Rump Length CRL accurate within +/- 3-5 days).
- ✓TSH check if pre-existing thyroid disorder or risk factors.
Upcoming Visit Horizon: Intake visit with family doctor, obstetrician, or midwife.