Academic Week 6 Flashcards
What are the three types of hypertension in pregnancy and how are they defined?
Chronic hypertension (which exists before pregnancy)
Gestational hypertension (that develops after 20 weeks gestation without proteinuria)
Pre-eclampsia (which is hypertension that develops after 20 weeks gestation with proteinuria).
What are the complications of pre-eclampsia?
This is the leading cause of maternal death.
For the mother:
Pre-eclamptic seizures, HELLP syndrome, stroke, pulmonary oedema, renal failure, liver failure and disseminated intravascular coagulopathy.
For the foetus:
Intrauterine growth restriction, premature delivery and subsequent respiratory distress syndrome and even some stillbirths.
These children are at higher risk of heart disease, hypertension, stroke and diabetes.
What are the risk factors for pre-eclampsia?
Primiparous, family history, personal history, older mothers, obese mothers, multiple pregnancy, pre-existing conditions of diabetes, hypertension or antiphospholipid syndrome and coagulation disorders.
What genes are involved in the genetic predisposition to pre-eclampsia?
Factor V leiden, prothrombin gene variant, MTHFR and angiotensinogen 235THr.
How does the genetic predisposition lead to the development of pre eclampsia?
The genetic predisposition causes an abnormal immune response in pregnancy.
This causes deficient trophoblast invasion so spiral arteries in pre-eclamptic women are not as dilated and have a higher resistance than normal spiral arteries. Higher pressure is needed to perfuse the foetus and hence pre-eclampsia develops.
This hypo perfusion causes intrauterine growth restriction.
The proteinuria occurs as a result of the calculate endothelial cells of the renal arteries being damaged.
How is pre-eclampsia treated?
The only cure is delivery of the baby.
Treatment is aimed at minimising the risk to the mother and extending gestation when it is safe to do so. Blood pressure control is achieved with labetolol, nifedipine and methyldopa.
Timely antenatal steroids promote fetal lung development if premature delivery is likely to occur.
Women at high risk of pre-eclampsia should be given prophylaxis with magnesium sulphate. Women who have had pre-eclampsia in previous pregnancies should take 150mg aspirin OD for the first trimester.
What is eclampsia and how is this managed?
Eclampsia is defined as seizure activity unrelated to other cerebral conditions in a pregnant woman with pre-eclampsia. There is no cure other than removal of the placenta. The aim of treatment is to prevent death by stabilising the mother. Treatment involves lowering blood pressure with labetalol or hydralazine, anticonvulsants of magnesium sulphate and strict fluid resuscitation to prevent pulmonary oedema. Remember, hypertension is not the problem, fluctuations in blood pressure are!
What are the risk factors for gestational diabetes?
BMI over 30, previous macrocosmic baby over 4.5 kg, previous gestational diabetes, family history of diabetes, south asian ethnicity and any woman who has developed glycosuria during pregnancy.
What is the definition of gestational diabetes?
Gestational Diabetes is defined as any degree of glucose intolerance with its onset or first recognition in pregnancy. This definition is independent of the treatment regime or whether or not the condition persists after pregnancy. This affects 7% of pregnancies.
How is gestational diabetes diagnosed?
Oral glucose tolerance test is used (2-hour 75g glucose often performed at 24-28 weeks). Diagnosis is made if the woman has a fasting plasma glucose of 5.6 mmol/L or above or a 2-hour plasma glucose level of 7.8 mmol/L or above.
How is gestational diabetes treated?
Treatment of women with GDM is dependent on regular monitoring of capillary blood glucose. Diet and exercise control is used for women with a fasting glucose below 7 mmol/L at diagnosis, metformin is used if blood glucose targets are not met within 2 weeks of diet and exercise changes and insulin can be used if this is still ineffective or the patient cannot tolerate metformin.
What are the complications of gestational diabetes?
Complications of GDM for the mother include higher chance of C-section, miscarriage, gestational hypertension and pre-eclampsia and a higher risk of a pre-term birth. The complications for the fetus include macrosomia, polyhydramnios, birth trauma like shoulder dystocia, stillbirth, prematurity and neonatal hypoglycaemia.
What is the definition of obstetric cholestasis?
Obstetric Cholestasis is also known as intrahepatic cholestasis of pregnancy and is a multifactorial condition characterised by pruritis in the absence of a rash with abnormal LFTs. Neither of these findings have an alternative cause and both resolve after delivery. This condition has a higher prevalence in Indian or Pakistani Asian communities and is associated with genetics and environmental factors.
How is obstetric cholestasis diagnosed?
Obstetric Cholestasis is diagnosed when otherwise unexplained pruritis occur in pregnancy and abnormal LFTs or raised bile acids occur in the pregnant woman and resolve after birth. This typically occurs in the third trimester and the pruritis normally affects the palms and soles and is worse at night. The differential diagnosis is Hepatitis A, B and C, Epstein Barr Virus, Cytomegalovirus, autoimmune liver disease and primary biliary sclerosis.
What are the risks of obstetric cholestasis?
Prematurity, meconium staining, increased chance of reoccurrence and possibly miscarriage
How is obstetric cholestasis managed?
Symptomatic relief with chlorphenamine for the itching and surveillance of the fetus.
Define a biological medicine
A biological medicine is defined as a medication whose active substance is made by or derived from a biological source. Any substance made in a laboratory from a living organism. These include insulin, vaccines, stem cells and tissue therapies. Biological drugs are usually of a high molecular weight and immunogenic.
Define biosimilars
Biosimilars is a biological medicine which is highly similar to another already approved biologic. It has a similar structure, biological activity, efficacy, safety and immunogenicity. These are not exact replications of biologic agents. A biosimilar can be considered for approval for one or more indications for which the reference product is approved, without itself being subjected to clinical testing for every indication.
What are the adverse reactions to biologics?
Standard infusion reactions occur within the first hour of infusion. the symptoms include fever, shaking chills, musculoskeletal pain, nausea, vomiting, diarrhoea and skin rashes. They are usually moderate in intensity but can be fatal.
Hypersensitivity reactions include degranulation of muscles and basophils, pruritis, urticaria and angioedema. They do not usually occur on 1st infusion but are triggered on subsequent infusions. All immediate reactions should be managed on an individual basis.
Non-immediate reactions include high cytokine release, cytokine storm, autoimmunity as seen in SLE, atopic dermatitis and depression. Biologics inhibit the immune system so increase the risk of infections such as TB, especially if they have latent TB. Live vaccines should be avoided such as BCG, MMR and Rubella. Risk of malignancy is unknown.
How is pre-term birth sub-categorised?
Pre-term is defined as babies born alive before 37 weeks of pregnancy are completed. There are sub-categories of pre-term birth based on gestational age:
- Extremely pre-term (<28 weeks)
- Very Pre-term (<32 weeks)
- Moderate to late preterm (32-37 weeks)
What are the causes of pre-term birth?
Causes of pre-term birth include uterine overdistention, cervical disease, breakdown of maternal-fetal tolerance, stress, decidual senescence, vascular disorders and infections.
What are the consequences to the baby in pre-term birth?
Cerebral palsy, impaired learning, vision problems, dental problems, behavioural and psychological illness and chronic health conditions.
When should vaginal progesterones be given?
When a patient has a cervix shorter than 25mm pre-term.
What infections can cause pre-term birth?
Infection in pregnancy which can cause pre-term birth include bacterial vaginosis, chlamydia, vaginal candidiasis and trichomonas vaginalis. Asymptomatic bacteriuria is a significant cause of pre-term birth meaning pregnant women are the only patient group who should receive antibiotics for asymptomatic bacteriuria.
How should a patient who is suspected to be pre-term be managed?
Treatment can be with a cervical cerclage, a purse strings suture that strengthens the cervix mechanically. Hormonal treatments with progesterone as this has an anti-inflammatory effect and reduces some tocolytic such as silent contractions. The cervical pessary is a mechanical silicon pessary which fits around the cervix to strengthen it.
How should threatened pre-term birth be managed?
Threatened pre-term labour is a diagnostic challenge and difficult therapeutically. If confirmed then it should be treated with corticosteroids and magnesium sulphate. This is very effective. Tocolytics are used to suppress contractions and temporarily arrest labour to give steroids and magnesium to improve outcomes for the baby.
What are the biochemical properties of the combined hormonal contraceptive pill and what are there effects?
Combined Hormonal Contraception contains ethinyl oestradiol (EE) which is a synthetic oestrogen. EE suppresses LH and FSH and inhibits ovulation. EE can stimulate hepatic production of sex hormone binding globulin (SHBG). The Combined Hormonal Contraceptive pill also used one of several progesterone which prevent over-proliferation of the endometrium, thicken cervical mucus and suppress ovulation.
How does the combined transdermal patch work?
The combined transdermal patch (CTP) is given through the brand Evra. It uses EE with norelgestromin. The patch is changed weekly, and hormones are absorbed through the skin. It is less effective in women who weigh more than 90kg.
What are the non-contraceptive benefits of the combined contraceptive methods?
There are many non-contraceptive benefits of the combined contractive methods. These include reduction of heavy menstrual bleeding, reduced menstrual pain, benefits for premenstrual syndrome symptoms (PMS), continuous CHC can reduce the risk of recurrence of endometriosis after surgical management, management of acne, management of hirsutism, management of irregular menstrual cycles associated with PCOS, reduction in headaches, mood changes, bloating, cramps, nausea, and breast discomfort and reduction in endometrial, ovarian and colorectal cancer risks.
Describe the mechanism of action of some progesterone only pills
Progesterone only methods include progesterone only pills and LARC (Long-acting reversible contraception) methods which require administration less than once per cycle such as injectable progesterones, sub dermal implants and intrauterine systems.
Desogestrel (DSG) containing the POP is taken daily with no hormone free interval. Brands include Cerazette and Zelleta. The must be taken daily within the same 12-hour window. They work by increasing the volume and viscosity of cervical mucus to prevent sperm penetration and ovulation is suppressed in 97% of cycles. It may also hinder implantation in the endometrium and reduce fallopian tube cilia activity.
The traditional POP is also taken daily with no hormone free interval. They have to be taken daily in the same 3-hour window. Examples include norethisterone and levonorgestrel. They work by increasing the volume and viscosity of cervical mucus and ovulation is suppressed in 50% of cycles. It may also hinder implantation and reduce fallopian cilia activity. This may increase the chance of an ectopic pregnancy.
