It should be done at 32–34 weeks of gestation for women with twins.

The recommended time of testing is 3–5 weeks prior to the anticipated delivery date- therefore  35–37 weeks of gestation in singleton pregnancies with no risk factors for preterm delivery.

Antenatal treatment for vaginal or rectal colonisation does not reduce the likelihood of GBS colonisation at the time of delivery and so is not indicated in this situation.

IAP should be offered to GBS-colonised women

Routine ultrasound screening is not useful. Selective ultrasound screening can be considered for women with breech presentation at term who are considering vaginal birth.

If the placenta is thought to be low lying (less than 20 mm from the internal os) or praevia
(covering the os) at the routine fetal anomaly scan, a follow-up ultrasound examination
including a TVS is recommended at 32 weeks of gestation to diagnose persistent low-lying
placenta and/or placenta praevia.

Use of TVS- to accurately see the placental edge. Also, cervical length is a predictor of antepartum bleeding and emergency preterm caesarean section in placenta praevia. Women with a cervical length of less than 31 mm have a 16 times higher risk of emergency
caesarean section due to massive haemorrhage.

• If the history suggests that the reaction described is not likely to be allergic in nature then penicillin should be given.
• If the history suggests an allergy to beta-lactams, but one that is not severe(i.e. no anaphylaxis, angioedema, respiratory distress or urticaria), then a cephalosporin can be administered.
• If the allergy to beta-lactams is severe then intravenous vancomycin is recommended.

Read about Intrapartum Care in VBAC-

https://obgresource.com/2021/12/10/intrapartum-care-in-vbac-2/

Non-hormonal contraceptive methods are recommended.

According to UKMEC- For women with 'Current breast cancer' , Cu IUCD is Category 1 , all other contraceptive methods are category 4.

For women with 'Past' breast cancer' , Cu IUCD is Category 1 , all other contraceptive methods are category 3.

Previous vaginal delivery, particularly previous VBAC, is the single best predictor of successful VBAC and is associated with a planned VBAC success rate of 85–90%.

Previous vaginal delivery is also independently associated
with a reduced risk of uterine rupture.

For potentially sensitising events after 20weeks gestation,
a minimum anti-D Ig dose of 500 IU should be administered within 72 h of the event.

• The timing of delivery should be tailored to the patient.
• If history of vaginal bleeding/ other risk factors for preterm delivery- consider ‘Late preterm delivery’- 34+0 to 36 +6 weeks.
• If uncomplicated placenta previa- Consider between 36+ 0 and 37+0.

Bonus info- There is at least one more condition in which the delivery should be delayed for some time after appearance of the condition- Chickenpox ! In varicella rash- planned delivery should normally be avoided for at least 7 days after the onset of the maternal rash to allow for the passive transfer of antibodies from mother to child.

When testing for GBS carrier status, a swab should be taken from the lower vagina and the anorectum.

A single swab (vagina then anorectum) or two different swabs can be used.