Drugs in Pregnancy

Safe Drugs in Pregnancy and Safe drugs in Lactation

Antipyretic, fever medications safe in pregnancy

• Paracetamol (acetaminophen) 1000mg QDS
  

Runny nose, itch, flu medication safe in pregnancy

• Chlorpheniramine (piriton) 4mg QDS

Cough Medication safe in pregnancy

• Dextromorphan (DMP) 15mg tds
• Diphenhydramine 10mls tds
• Bromhexine (Bisolvon) 8mg tds

Sore Throat medication safe in pregnancy

• Lozenges

Anti vomiting medication safe in pregnancy

• Pyridoxine 50mg OM (for hyperemesis gravidarum)
• Metoclopramide (Maxolon) 10mg tds

Anti- Diarrhoea medication safe in pregnancy

• Charcoal 1 tablet tds

Antibiotics safe in pregnancy

• Amoxycillin 500mg tds
• Erythromycin 500mg tds
• Cephalexin 500mg tds
• Augmentin (Amoxycillin-clavulanate acid) 625mg bd to tds

Epilepsy in Pregnancy

About 1 in 200 women have epilepsy. During pregnancy, seizure control can become worse and there is a risk of congenital defect of the fetus, especially neural tube defects. This is cause mostly by drugs and monotherapy is generally preferred to multi-drug therapy.
The fetus also have a higher chance of developing epilepsy (4%)

All epileptic women who are planning for pregnancy should be started on folic acid and this should be continued throughout pregnancy.
Vitamin K orally should be given in the last 4 weeks of pregnancy. reduce chance of coagulopathy in neonates.

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.

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

Common symptoms of pregnancy

• Itching is common in pregnancy.

• Abdominal pain is almost always present and is usually benign.

• Heart burn affects up to 2/3 of pregnant women
• Backache is present in almost all pregnant women
• Constipation is common and is usually worsen by any iron supplement.
• Leg swelling is common but needs to be followed up by a doctor
• Leg cramps happens to approximately 1/3 of the ladies.
• Carpal tunnel syndrome may happen due to fluid retention
• Candida infection of the vagina may happen
  

APGAR Soring in neonates

The APGAR scoring is done when baby is born and at 5 minutes
The first scoring decides if any further rescue is needed for the baby
The 2nd scoring helps to give a prognostication of the baby's health

Heart rate
0 - Absent
1 - <100
2 - >100

Respiratory Effort
0 - Absent
1 - Weak
2 Strong Cry

Muscle
0 - Absent
1 - Limb flexion
2- Active Motion

Colour
0 - All Blue
1- Extremities Blue
2- All Pink

Reflex
0 - No response
1 - Grimace
2- Cry

Advice for pregnant women

There are a few common questions as to what the pregnancy women can consume during pregnancy. These are the general advice

Medications should be generally avoided, particularly in the first trimester. All pregnant women should be on folic acid supplement of 0.4mg per day. This should continue till at least 12 weeks of pregnancy.

Pregnant lady should generally avoid alcohol completely, although there is no known evidence of problems for drinking less than 2 units of alcohol a week.

Caffeine (coffee) is also generally avoided, again 1 cup a day seem to be the maximum allowed amount.

Smoking is an absolute no go and all women should stop smoking completely during the pregnancy. Smoking is known to increase the risk of miscarriage, pre-term labour and growth problems in the baby.

Light exercise is generally advised. Sexual intercourse is allowed unless the pregnant lady has certain conditions like placenta previa of which the doctor will advise the couple to avoid coitus.

Pregnancy Signs

These are the signs of pregnancy

• Menses not here (Amenorrhoea)
• Nausea and or vomiting
• Breast tenderness
• Urinary Frequency (Late sign)
  

How to estimate gestation age

• From the Last menstrual period (LMP)and using Nagle's rule

- Provided the menses is regular
- Need to adjust if usual period is more or less than 28 days

• Using Ultrasound scan

- Measuring the crown rump length (week 7 to week 14)
- Parietal diameter or femur length (Week 14 to week 20)
- Not useful for dating beyond 20 weeks
- More accurate than LMP

First visit to the obstetric doctor

The fist visit to the obstetric doctor is often scary. But this is one of the times when visiting the doctor does not mean you are sick. Here is what to expect on your first visit to the doctor. He will first begin by asking a series of questions known as history.

History

Personal
Name
Age
Occupation
Gestation (previous pregnancy)
Parity (previous child birth)

Present Pregnancy
Last Menstrual Period (LMP) :
- was it regular
- Any recent use of Oral Contraceptive (OCP)
Calculated Estimated Delivery date (EDD):
- Add 1 year and 7 days and subtract 3 months (Nagle's rule)
- Use an obstetric wheel

Complication of pregnancy
Any bleeding
Diabetes
Hypertension
Anemia or thalessemia
Urine infection
Concerns

Past Obstetric History
Mode of delivery
Gestation age
Birthweight and sex
Any complications
Any infection
Any gynaecological history

Physical Examinations
Height and weight
Temperature
Oedema/swelling of the ankle
Any pallor/anemia
Blood pressure
Cardiovascular examination
Abdominal examination
- Uterus palpable at 12-14 weeks
- Fundus (top of uterus felt) at umbilical at 20 weeks
- Any scars
- Any Linear Nigra
- Lie and presentation
- Fetal movement
Doppler Ultrasound: to listen to fetal heart beat

That is summary is the first visit to the doctor