Gestational Diabetes in pregnancy

Pregnancy causes increase in glucose intolerance. For some women, this can lead to gestational diabetes. In general, insulin requirement of a women increases during pregnancy. Approximately 8.6% of all pregnancy are complicated by gestational diabetes.

Definition of gestational diabetes (GDM)

• The diagnosis of gestational diabetes is based on an oral glucose tolerance test (OGTT) in which a 75g load of glucose is given to the patient.
• GDM is diagnosed if (ADA guidelines 2011)
  

• - Fasting ≥92 mg/dl (5.1 mmol/l)

• - 1 h ≥180 mg/dl (10.0 mmol/l)

• - 2 h ≥153 mg/dl (8.5 mmol/l)

When and how to screen for Gestational Diabetes
There has been no consensus on this issue. The ADA and RCOG (Jan 2011) recommends the following:

• Screen for undiagnosed type 2 diabetes at the first prenatal visit in those with risk factors, using standard diagnostic criteria.

• In pregnant women not known to have diabetes, screen for GDM at 24–28 weeks of gestation, using a 75-g 2-h OGTT

• Screen women with GDM for persistent diabetes 6 weeks postpartum.
  

• Women with a history of GDM should have lifelong screening for the development of diabetes or prediabetes at least every 3 years.

In Singapore, the MOH reccommends OGTT only for high risk patients early in the pregnancy and at 26-28 weeks
In all other patients urine should be tested for glucose. If glucosuria 1+ or more, plasma glucose levels will be done. OGTT is done if glucose >6.6 more tahn 2 hrs after meal or >7.0 within 2 hrs after meal.


Risk Factors for Gestational Diabetes

• Obesity
• Family history of diabetes
• Medical history of gestational diabetes
• History of large baby more than 4kg
• Previous unexplained stillbirth
• PCOS
• Polyhydramnious
• Twin
  

Fetal Complications for diabetic women

• Related to glucose levels
• Congenital abnormalities
• Pre-term labour
• Polyhydramnios
  
• Decrease fetal lung maturity
• Large baby
• Fetal distress and sudden fetal death more common.
• Neonatal Hypoglycemia
  

Maternal Complications of Diabetes in pregnancy

• Ketoacidosis (rare)
• Hypoglycemia (too strict control)
• UTI
• Infection: Wound or endometrial
• Hypertension and pre-eclampsia more common,
• Diabetic retinopathy

Management of patients with gestational diabetes

• Close surveillance
  
• Dietary Control: Maintain fasting glucose at <5.5 mmol/L and 2hr post prandial glucose at <6.7 mml/L
  
• Metformin and Glibenclamide has been used is oral agents
• Insulin still the safest choice.
• Mothers should monitor fetal movement in last 12 weeks of pregnancy
• Ultrasound for congenital abnormalities at 18-22 weeks
• Fetal growth ultrasound 29-33 weeks
• Non stress cardiotocography with umbilical doppler flow may be considered.
• Screen for hypertension.
• Infants fed early and baby screen for hypoglycemia
• Contraception: OCP in complicated diabetes or infection with IUCD.

Triple test screening for down syndome

This test measures 3 hormones:

• AFP (alpha fetal protein)
• HCG
• Estriol

This helps to screen for down syndrome and AFP helps to screen for neural tube defects.
The mother undergoes a blood test between 14 weeks to 20 weeks. The blood test results generally takes a few days to be available.
The detection rate for down syndrome is about 65%

Cobine Screening: Nuchal transluncency and first trimester screening

Nuchal Transluncy test as described in the previous post, can be combined with doing a blood test.
The blood test measures 2 items:

• Free beta HCG
• PMPPA (pregnanct associated plasma protein A)

Like the Nuchal translucency test, this is done between 11 week 3 days to 13 weeks 6 days. The blood test results barely takes a few hours for the results to be available.
The detection rate of down syndrome is improved with this test at up to 90%

Nuchal Translucency Test Screening

The Nuchal transluncency test is an ultrasound test. It measures a fluid filled area at the back of the neck of the fetus called nuchal. The test is done between 11 week 3 days to 13 weeks 6 days of pregnancy

Detection rate of Chromosomal disorder via NT test alone is about 80%

Signs of of Pre-eclampsia in pregnancy

Definition:

• Pre-eclampsia is a multi system disorder characterised by hypertension and proteinuria. It is difficult to define clinically due to it's heterogeneous nature.
• It is defined as blood pressure of more than 140/90 and more than 300mg/24hr of protein in the urine.
• In women who are hypertensive, a rise of systolic of more than 30mmHg or diastolic of more than 15mmHg is taken.
• Affects 5% to 10% of pregnancies
  

Pathophysiology:

• Believed to be placenta in origin
• Increase vascular resistance : hypertension
• Increase vascular permeability: proteinuria, edema
  
• Decrease placenta blood flow: Intra-uterine growth restriction
• Decrease cerebral perfusion: Eclampsia
• Edothelial cell damage: Clotting abnormality and liver damage

Classification of pre-eclampsia

• Mild - BP <170/110
• Moderate - BP >170/110
• Severe - Pre-eclampsia <32>

Risk factors for pre-eclampsia

• Nulliparous
• Previous pre-eclampsia
• Family history of pre-eclampsia
• Extremes of maternal age
• Large placeneta : eg twin
• Microvascular disease : DM, renal disease, autoimmune disease
• Existing hypertension
• Obesity

Symptoms of Pre-eclampsia

• Central nervous system: Headache, drowsy, visual problems
• Gastro-intenstinal: Nausea, vomting, epogastric pain

Signs of Pre-eclampsia

• Hypertension
• Edema
• Clonus
• Epigastric tenderness

Complications of pre-eclampsia and treatment of problems

• Eclampsia : grand mal seizure - treat with IV magnesium sulphate
  
• Cerebral hemorrhage: Preventing BP of more than 170/110 (belived to prevent loss of autoregulation)
• HELLP: Hemolysis, Elevated Liver enzymes, Low Platelets. - supportive
  
• DIVC (disseminated intra-vascular coagulation)
• Renal failure: May need dialysis
  
• Pulmonary edema: Frusemide, ventilation
• Fetal: IUGR, Placental abruption, fetal hypoxia

Prevention of pre-eclampsia

• Patients with previous severe or early onset pre-eclampsia should be offered low dose aspirin.

Admission criteria for pre-eclampsia

• BP> 160/110
• Any complications
• Once proteinuria 1+ (admit for 24hr UTP)or >300mg/24hr

Management of Pre-eclampsia

• Monitor for complications: Fetal and blood and clinical monitoring
• Control BP: Oral nifedipine and methyldopa (s.e depression, loss of patellar reflex)
• Steroids if gestation <34>
• Delivery (Eclampsia can still happen up to 24hrs post delivery)
  

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.