Maternal Adaptation to Pregnancy

Maternal physiology
During pregnancy, the woman undergoes many physiological changes, which are entirely normal, including cardiovascular, hematologic, metabolic, renal and respiratory changes that become very important in the event of complications.

Cardiovascular
The woman is the sole provider of nourishment for the embryo and later, the fetus, and so her plasma and blood volume slowly increase by 40-50% over the course of the pregnancy to accommodate the changes. This results in overall vasodilation, an increase in heart rate (15 beats/min more than usual), stroke volume, and cardiac output. Cardiac output increases by about 50%, mostly during the first trimester. The systemic vascular resistance also drops due to the smooth muscle relaxation caused by elevated progesterone, leading to a fall in blood pressure. Diastolic blood pressure consequently decreases between 12-26 weeks, and increases again to prepregnancy levels by 36 weeks. If the blood pressure remains abnormal beyond 36 weeks, the woman should be investigated for pre-eclampsia, a condition that precedes eclampsia.

Hematology
The plasma volume increases by 50% and the red blood cell volume increases only by 20-30%.
Consequently, the hematocrit decreases.
White blood cell count increases and may peak at over 20 mil/mL in stressful conditions.
Decrease in platelet concentration to a minimal normal values of 100-150 mil/mL
The pregnant woman also becomes hypercoagulable due to increased liver production of coagulation factors, mainly fibrinogen and factor VIII.

Metabolism
During pregnancy, both protein metabolism and carbohydrate metabolism are affected. One kilogram of extra protein is deposited, with half going to the fetus and placenta, and another half going to uterine contractile proteins, breast glandular tissue, plasma protein, and hemoglobin.

Nutrition
Increased caloric requirement by 300 kcal/day
Gain of 20 to 30 lb (10 to 15 kg)
Increased protein requirement to 70 or 75 g/day
Increased folate requirement from 0.4 to 0.8 mg/day (important in preventing neural tube defects)
All patients are advised to take prenatal vitamins to compensate for the increased nutritional requirements. The use of Omega 3 fatty acids supports mental and visual development of infants. Choline supplementation of research mammals supports mental development that lasts throughout life.

Gastrointestinal
nausea and vomiting ("morning sickness") may be due to elevated B-hCG, which should resolve by 14 to 16 weeks
prolonged gastric empty time
decreased gastroesophageal sphincter tone, which can lead to acid reflux
decreased colonic motility, which leads to increased water absorption and constipation

Renal
Increase in kidney and ureter size
Increased glomerular filtration rate (GFR) by 50%, which subsides around 20 weeks postpartum
Decreased BUN (blood urea nitrogen) and creatinine, and glucosuria (due to saturated tubular reabsorption)
Persistent glucosuria can suggest gestational diabetes
Increased renin-angiotensin system, causing increased aldosterone levels
Plasma sodium does not change because this is offset by the increase in GFR

Pulmonary
Increased tidal volume (30-40%)
Decreased total lung capacity (TLC) by 5% due to elevation of diaphragm from uteral compression
Decreased expiratory reserve volume
Increased minute ventilation (30-40%) which causes a decrease in PaCO2 and a compensated respiratory alkalosis
All of these changes can contribute to the dyspnea (shortness of breath) that a pregnant woman may experience.

Endocrine
Increased estrogen, which is mainly produced in the placenta
Fetal well being is associated with maternal estrogen levels
Causes an increase in thyroxine-binding globulin (TBG)
Increased human chorionic gonadotropin (β-hCG), which is produced by the placenta. This maintains progesterone production by the corpus luteum
Human placental lactogen (hPL) is produced by the placenta and ensures nutrient supply to the fetus. It also causes lipolysis and is an insulin antagonist, which is a diabetogenic effect.
Increased progesterone production, first by corpus luteum and later by the placenta. Its main course of action is to relax smooth muscle.
Increased prolactin
Increased alkaline phosphatase

Musculoskeleton and dermatology
Lower back pain due to a shift in gravity
Increased estrogen can cause spider angiomata and palmar erythema
Increase melanocyte-stimulating hormone (MSH) can cause hyperpigmentation of nipples, umbilicus, abdominal midline (linea nigra), perineum, and face (melasma or chloasma)

Others
Edema, or swelling, of the feet is common during pregnancy, partly because the enlarging uterus compresses veins and lymphatic drainage from the legs.

New RCOG Guidelines

UMBILICAL CORD PROLAPSE

Cord prolapse has been defined as the descent of the umbilical cord through the cervix alongside (occult) or past the presenting part (overt) in the presence of ruptured membranes.1,2 Cord presentation is the presence of the umbilical cord between the fetal presenting part and the cervix, with or without membrane rupture.

The overall incidence of cord prolapse ranges from 0.1% to 0.6%. In the case of breech presentation, the incidence is slightly higher than 1%.12 It has been reported that male fetuses appear to be predisposed to cord prolapse. The incidence is influenced by population characteristics and is higher where there is a large percentage of multiple gestations.

To view the RCOG Guidelines click here

ORAL CONTRACEPTIVE USE AND CANCER RISK

New evidence
A paper published in September 2007 in the BMJ from Hannaford et al has reported
findings on the use of oral contraceptives and cancer risk.

Key findings
• contraceptive pill use is associated with a 12% decrease in the risk of
developing cancer overall
• there is a statistically significant reduction in the rates of large bowel or
rectal cancer and cancer of the uterine body or ovaries
• there are no differences between ever and never users in their risk of
breast cancer
• there was no increase in the risk of cancers of the lung, cervix, central
nervous system overall
• there was a very small increased risk in cervical cancer in women using
OC for , 8 years (rate 38 per 100 000 woman years)


Reference
Hannaford P, Selvaraja S, Elliot, A, Angus V, Iversen L and Lee A. Cancer risk among users of oral contraceptives: cohort data from the royal College of General Practitioner’s oral contraceptive study. British Medical Journal September 2007 www.bmj.com)

Part I MRCOG Online Course, Based on New Curriculum

Part I MRCOG Online Course,
Based on new RCOG Curriculum

Dear MRCOG candidate

Get yourself prepared and practice online from the biggest online database

Part I MRCOG Online Revision MCQs & EMQs

4000 MCQs covering all the subjects according to the RCOG updated Syllabus

300 EMQs With new style recommended by the RCOG in forthcoming exam

Subscription Expires at exam date
You can use and benefit from your revision till exam time

To make your payment
Log in to http://www.mrcogexam.org.uk/ and Register

Click Add Subject
Choose the required Course or Subject

If you are already registered then Click Add subject from your control Panel
If you require any assistance, Contact us at info@mrcogexam.org.uk

Course Briefing:
Part I MRCOG Exam Online Course is an online MCQs database
Course Material and practice are done online.
Practice the question in exam like format.
Mark each question individually to see your progress.
Stop at any point and get back to it at any time.
Tackle more than one subject simultaneously.
Search your question database to have a custom exam on one topic (eg, Ovary)
No repetition or replication

Part I MRCOG Online Course Consists of the following:
 Individual Subjects Practice
 Part I MRCOG EMQs
 Paper I and Paper II Mock Exams
 Final Revision Papers

Individual Subjects Practice
Practice online from a huge library of MCQs.
(Biggest MCQs database online) more than 4000 MCQs
Questions encountered at past papers.
Answers are updated on regular basis.
Get feed back by email on question you are query about.
Mark your answers instantly and see your progress


Part I EMQs Practice
Practice online from a huge library of EMQs. (Biggest EMQs database online) more than 300 EMQs

Paper I and Paper II Mock Exams
Practice online in Exam like conditions (Number of question, Timing)
Each Time you practice the MOCK Exams you get a different set of questions, (Endless Random Combination of questions)


http://www.mrcogexam.org.uk/

Register Now

Part II MRCOG Online Revision Courses

Dear MRCOG Candidate

Mrcogexam.org.uk is dedicated to “The assistance and support for all Candidates applying for the MRCOG (Membership of the Royal College of Obstetricians and Gynaecologists).

www.mrcogexam.org.uk is a web based learning Resource intended to complement your theoretical knowledge.

We all have gaps in our knowledge; by training and practice we aim to fill these gaps

Course Structure

• 120 Short Essay Question (sets of short answer essay lessons; equivalent to 30 set of exam papers.)

• The new style short answer essay format

• 3000 MCQs Covering the entire syllabus targeting questions which encountered at past exams.

• 400 EMQs with detailed explanations.

• Answers to difficult Past Papers MCQs and Essays

You can purchase the whole Course or each item can be purchased separately (Essay Course, EMQ Course, MCQ Course); helping candidates who want to improve in a particular area save their money.

Register Now