THIRD TRIMESTER PROBLEMS Hypertension Small for dates Post-term pregnancy

Hypertension A 35 yr old primigravida whose booking BP was 16wks presents to the 36wks with a BP : 150/95 and urinalysis showing 2+ protein ( 1g/L ) and mild pitting oedema.

Hypertension This woman shows signs of : a) Pre-eclampsia b) Gestational hypertension c) Essential hypertension d) Chronic renal disease

Hypertension Consider differential diagnosis Accuracy of BP measurement Helpful laboratory tests including urate, platelets, liver fn tests,coagulation profile, renal fn tests.

Hypertension : management options a) Commence antihypertensive treatment (methyl dopa 250mg tds) and review in 2d b) Suggest enforced bed rest,restrict salt and control fluid intake c) Arrange for hospital admission and assessment

Pre-eclampsia : pathophysiology Arteriolar vasospasm Disturbed coagulation profile Disturbed renal function and fluid balance

Pre-eclampsia : aims of management Minimise risks to mother (hypertension,renal fn,convulsions) Monitor progress of fetus Timely and appropriate method of delivery Systemic disease that can only be reversed by terminating the pregnancy

The small for dates baby A 25 yr old G(3)P(2) 34wks for a routine A/N visit and shows a fundal height measurement of 31cm. Her own BthWt at term was 2.7kg and she currently weighs 55kg.

Small for Dates Ultrasound examination shows: AC : 27cm (31wks) EFW: 1.8kg (~10% ) normal liquor (AFI 10cm) Fetal movement/breathing/umbilical doppler

Small for dates This woman’s baby has: a) IUGR b) A constitutionally small baby c) Cannot discriminate between the above until postnatal growth assessed

Small for dates Consider discriminating factors a) life style b) effect of maternal wt and birth wt c) past obstetric history (previous bth wts) Clinical assessment –symph/fundal ht Definition SFD vs IUGR

Small for dates-management options a) give dietary supplements and monitor maternal wt gain b) commence aspirin therapy c) see wkly and repeat growth study in 2wks

Small for dates Important Growth scan parameters Increase in AC by 1cm in 2wks Maintainance of liquor vol (AFI >8cm) Biophysical parameters assessed (movement/breathing/doppler) Centile ranking

Small for dates Consider lifestyle issues smoking, bedrest, work at home and outside Dietary supplements or medication eg aspirin

Post-term pregnancy A recent immigrant to Aust arrives saying she is a week overdue according to uncertain dates, you would: a) arrange admission for immediate IOL b) arrange plain XR to confirm fetal epiphyses c) arrange US for dating and wellfare d) send pt to first available ANC and leave them sort it out

Post-term pregnancy Definition (38-42wks) Problems in past prior to US dating (now ~2.5%) Rationale for considering IOL (PNM rate doubles by 43wks)

Post-term pregnancy Risks to the post term baby include: Reduced liquor vol and increased mec staining Decreasing placental fn may be more difficult to assess Macrosomia with attendant obstet complications eg shoulder dysocia