Normal Blood Pressure in pregnancy

Blood pressure of a pregnant women commonly falls from the first trimester of pregnancy to it's lowest value during the second trimester. The maximum drop in BP is usually around systolic BP of 30 and diastolic BP of 15.
BP returns back to pre-pregnant levels by term.

Hypertension in pregnancy occurs when there is an increase of BP more than 140/90 in the 2nd half of pregnancy and is due to increase vascular resistance. Protein excretion in pregnancy should be less than 0.5g/24hr.
Patients who develop pregnancy induced hypertension are at increase risk of developing hypertension later in life.

Signs of ectopic pregnancy

Definition of ectopic pregnancy: Implantation of a conceptus outside the uterine cavity.
Occurs approximately 1 in 1000 pregnancy. 95% of which is tubal ectopic.

Risk factors for ectopic pregnancy

• History of infertility of assisted conception
• History of pelvic inflmmatory disease
• Endometriosis
• Prev pelvic surgery
• Previous ectopic pregnancy
• IUCD
• Smoking
• Higher maternal age
  

Symptoms of ectopic prenancy

• Mostly asymptomatic
• Abdominal pain
• Dark PV bleed
• Shoulder tip pain (ruptured ectopic with intra-abdominal blood irritating diaphragm)

Signs of ectopic pregnancy

• Abdominal tenderness
• Adnexum tenderness
• Cervical excitation
  

Investigations of ectopic pregnanacy

• Serum HCG >1500 or 66% rise in 48 hr suggestive of intra-uterine pregnancy
  
• Trans vaginal Ultrasound
• Laproscopy is gold standard

Treatment of ectopic pregnancy

• Expectant: under strict criteria
• Medical: Methotrexate -use contraception for 3 months as teratogenic
• Surgical: Laproscopy vs Laprotomy. Salpingectomy or Salpingostomy
• Anti-D in rhesus negative patients
  

Signs of Miscarriage

Types of Miscarriages:

• Threatened miscarriage: Bleeding, fetus alive, os closed. 1/4 go on to miscarriage
• Inevitable Miscarriage: Bleeding but os is open even though fetus is alive
• Incomplete Miscarriage: Some fetal part remains in the uterus, os open
• Complete Miscarriage: Fetal part passed, os closed

Chromosomal abnormalities accounts for most of the spontaneous abortions.
Exercises, sexual intercourse and stress do not cause miscarriage.

Causes of recurrent miscarriages:
Autoimmune disease
Chromosomal defects
PCOS
Anatomical problems
Infections: eg bacterial vaginosis
Smoking
High maternal age
Obesity

Down' Syndrome Screenings

Down syndrome is also known as trisomy 21. It is the most common identifiable cause of learning disorder. Average life expectancy is 50 years old. About 1 in 10 die before age of 10.

The risk of down's syndrome in directly related to maternal age

• 25 years 1 in 1500
  
• 30 years 1 in 900
• 35 years 1 in 400
• 40 years 1 in 100
• 45 years 1 in 30

Screening Test for Down's Syndrome: Combine test

• 11 to 13 weeks
• Ultrasound: Nuchal Translucency (NT)
  
• Blood test:
• - Pregnancy associated plasma protein A (PAPP-A)
• - B-HCG
  

Interpreting the combine screening test

• 90% sensitive (detects 90%)
• 5% false positive

Screening Test for Down's Syndrome: Integrated test

• NT at 10 to 13 weeks
  
• PAPPA 10 weeks
• Oestriol, HCG, AFP, inhibin A in 15 weeks (Quadruple test)

Interpretation:

• 85% Sensitive
• 1.2% False positive
  
• Results out only after 15 weeks

These are the 2 most common tests. Other include the Quadruple test, serum integrated test (PAPP-A 10 weeks and quadruple test 15 weeks).

Amniocentesis and Chorionic Villus Sampling

When a screening test turns out positive, your obstetrician will recommend more accurate diagnostic test. There are 2 main prenatal test current.

Amniocentesis
A small needle is guided into the amniotic sac to draw out some amniotic fluid. The fluid is then used to culture fetal cells. These are tested for any abnormalities in the DNA. This can be only done from 15 weeks of gestation onwards. The main risk is that of miscarriage and is about 1%. Other risk includes not being able to culture fetal cells.

Chorionic Villus Sampling
This is done by using a small needle to withdraw some cells from the placenta. This is done with ultrasound guidance and can be done trans-abdominally or trans-cervically.
The test can be done around 10 to 13 weeks of gestation. The risk if miscarriage is about 1% but purportedly slightly higher than amniocentesis.

Ultrasound in Pregnancy

Before 14 weeks, ultrasound is use for dating purposes.
Dating becomes inaccurate after 14 weeks.

A fetal abnormality scan is done at 20 weeks. This will pick up deformities such as ancephaly ( absence of skull/brain), cleft lip or club foot ( congenital talipes equinovarus). Polyhydramnios (excessive amniotic fluid) can also be picked up during this stage.

The ultrasound can also measure for nuchal tranluceny from 11 to 14 weeks as a screening test for Down's syndrome.

Screening test in pregnacy

When the doctor talks about screening test, this often confuses people. Patients get very worried when screening test are positive. However this does not mean the disease is confirmed


A screening test checks the chances of the fetus having a certain disease. When screening test results are positive, it means that the fetus has a higher chance of having the disease, but this is not confirmed.

Confirmation is via a diagnostic test. Why not do a diagnostic test right the from start then?
This is because diagnostic test are usually more expensive, or more difficult to perform and often carry a higher risk.

A screening test should be:

• Widely available
• Cheap
• Sensitive
  
• Specific
• Non invasive
• safe
• there must be a diagnostic test for follow up