GROW Obstetrics

15/05/2026

21/04/2026

Ovarian reserve & ageing — simplified

1. We are born with all our eggs

* At birth: millions of primordial follicles
* No new eggs are made later in life

2. Gradual decline over time

* Eggs are continuously lost (atresia)
* This happens even when not trying for pregnancy

3. Reproductive years

* Small follicles grow each cycle → antral follicles
* These are what we measure on ultrasound (AFC)
* Blood test (AMH) reflects the pool of early follicles

4. AMH vs AFC

* AMH: declines earlier → early marker of ovarian ageing
* AFC: fluctuates cycle to cycle but trends down over time

5. 10–15 years before menopause

* Significant drop in ovarian reserve begins
* Fertility decline often precedes menopause by years

6. Menopause

* Very few follicles remain
* Ovarian function declines → hormonal changes

21/04/2026

13/01/2026

It helps assess:

1. Baby’s Growth & Size
• Detects small-for-gestational-age (SGA) babies
• Detects large babies (important for diabetes, shoulder dystocia risk, birth planning)
• Allows earlier intervention if growth slows (helps reduce stillbirth risk)

2. Placental Function
• By combining growth + Doppler studies, we assess if the placenta is working well
• Can detect placental insufficiency which linked with growth restriction & adverse outcomes

3. Amniotic Fluid
• Low fluid (oligohydramnios) or high fluid (polyhydramnios) can signal:
• placental issues
• diabetes
• membrane leaks
• fetal anomalies
Early detection changes management.

4. Umbilical Cord & Blood Flow (Dopplers)

Dopplers help check blood flow to the fetus. They guide:
• Frequency of monitoring
• Timing of delivery
• Need for steroid administration if early birth is likely

5. Fetal Position

Late pregnancy scan confirms the accurate position which helps with birth planning

10/01/2026

Bushfire smoke contains fine particles that can irritate the lungs, increase inflammation and affect both maternal and fetal wellbeing.

👉🏻During periods of smoke exposure, it’s important to:

• Minimise time outdoors and reduce exposure
• Avoid outdoor exercise
• Stay indoors with air-conditioning when possible
• Commercial air-conditioning filters can help reduce fine particles — so time in indoor venues (cinemas, libraries, shopping centres) may be protective
• Continue any prescribed respiratory medications
• See your GP if you have respiratory or general health concerns

👉🏻Be alert for symptoms that need medical review:

• Regular contractions or significant abdominal pain before 37 weeks
• Vaginal bleeding or increased loss of fluid
• Severe headache or visual changes
• Decreased fetal movements

👉🏻Short-term smoke exposure may increase respiratory symptoms.
👉🏻Prolonged or repeated exposure has been associated with increased risks of high blood pressure, premature birth and low birthweight — with risk increasing with the degree and duration of exposure.

06/01/2026

Chances of vaginal birth (approximate ranges)

1️⃣ Mild deflexion (e.g. occiput posterior, high head)
• Common early in labour
• Often flexes and engages with contractions

➡ Vaginal birth: ~50–70%
(especially in multiparous women)

2️⃣ Persistent deflexion in established labour
• Head remains high and deflexed despite good contractions
• Suggests fetopelvic mismatch or malposition

➡ Vaginal birth: ~20–40%

3️⃣ Marked deflexion (brow or face presentation)
• Brow presentation: largest diameter → usually impossible vaginally


➡ Vaginal birth:
• Brow: