obs Flashcards
pre-eclampsia
Mild preeclampsia is defined as the presence of hypertension (BP ≥140/90 mm Hg) on 2 occasions, at least 6 hours apart, but without evidence of end-organ damage, in a woman who was normotensive before 20 weeks’ gestation.
But if a patient has preexisting essential hypertension, preeclampsia is diagnosed if SBP has increased by 30 mm Hg or if DBP has increased by 15 mm Hg.
Severe preeclampsia is defined as the presence of 1 of the following symptoms or signs in the presence of preeclampsia:
- SBP of 160 mm Hg or higher or DBP of 110 mm Hg or higher on 2 occasions at least 6 hours apart
- Proteinuria of more than 5 g in a 24-hour collection or more than 3+ on 2 random urine samples collected at least 4 hours apart
- Pulmonary edema or cyanosis
- Oliguria (< 400 mL in 24 hours)
- Persistent headaches
- Epigastric pain and/or impaired liver function
- Thrombocytopenia
- Oligohydramnios, decreased fetal growth, or placental abruption
Intravenous labetalol or hydralazine should be considered as first-line agents for acute therapy of severe hypertension.
pathogenetic mechanisms of pre-eclampsia are best attributed to
uteroplacental ischaemia
Gestational Thrombocytopenia
– Benign. Mild and asymptomatic thrombocytopenia
– No past history of thrombocytopenia (except
possibly during a previous pregnancy)
– Occurrence during late gestation
– No association with fetal thrombocytopenia
– Spontaneous resolution after delivery.
– Platelet counts are typically greater than 70,000/microL, with about two-thirds being 130,000 to 150,000/microL.
– Frequency 5%.
congenital CMV infection
● The occurrence of fetal infection increases with advancing gestational age in women with primary CMV infection, though the occurrence of symptomatic disease decreases with advancing gestational age and is unlikely if a primary maternal infection occurs near term.
- Preconception period (two months to three weeks before the date of conception): 5.2 percent
- Periconceptional period (three weeks before to three weeks after the date of conception): 16.4 percent
- First trimester: 36.5 percent
- Second trimester: 40.1 percent
- Third trimester: 65 percent
● Once fetal infection occurs, the frequency of newborn disease and long-term sequelae is similar for infants of mothers with primary CMV infection during pregnancy and those who were CMV seropositive prior to pregnancy.
● Congenital infection may be symptomatic or asymptomatic in newborns. Most congenital infections are asymptomatic in the neonatal period.
● Both symptomatic and asymptomatic infected newborns are at risk for development of adverse sequelae in early childhood, but symptomatic newborns are at higher risk (eg, death 5 versus 0 percent, deafness 50 versus 10 percent).
mild - mod hypertension rx in pregnancy
Treatment of mild-moderate hypertension in pregnancy will NOT reduce the risk of the following outcomes:
1) superimposed preeclampsia
2) placental abruption
3) intrauterine growth retardation
4) Premature delivery
5) Perinatal mortality
6) Long term sequalae of hypertension
Treatment decreases the risk of:
1) Progression to severe hypertension
2) Respiratory distress in neonate
3) Induction of labour
4) Maternal stroke
Indications for IV Magnesium
1) Neurological signs in pre-eclampsia
2) Severe pre-eclampsia
3) Pre-eclampsia in developing countries
4) Less than 30 weeks delivery
NNT is 91.
Magnesium sulphate is thought to decrease the permeability of the blood brain barrier and also acts as a vasodilator.
Treatment of Grave’s disease:
Grave’s disease is the commonest cause of thyrotoxicosis in women of reproductive age.
1) Beta-blocker
– provide rapid partial symptomatic control
2) Thionamides (Carbimazole, Methimazole, PTU)
– inhibit thyroid hormone synthesis by interfering with thyroid peroxidase-mediated iodination of tyrosine residues in thyroglobulin
– However only PTU blocks the conversion of T4 to T3 within the thyroid and in peripheral tissues
– S/E: skin reaction, agranulocytosis.
– Treat for 12- 18 months
– Measurement of TSHr Ab titre prior to cessation of treatment may predict relapse.
3) Iodine131
– given to patients of all ages except in pregnancy and while breastfeeding.
– It accumulates in the thyroid and destroys the gland by local radiation but takes several months to
be fully effective.
– Patients must be euthyroid before treatment
– causes permanent hypothyroidism
4) Surgery: subtotal thyroidectomy:
– permanent hypothyroidism.
– risk of recurrent laryngeal nerve damage.
Indications for either surgery or radioiodine are: – patient choice – persistent drug side-effects – poor compliance with drug therapy – recurrent hyperthyroidism after drugs.
Mechanisms leading to increased risk of thrombosis in pregnancy
– Increased fibrin formation
– Decrease fibrinolysis
– Increased activity of fibrinolytic inhibitors PAI-1 and PAI-2
– Increase coagulation factors II, VII, VIII, X
– Decrease Protein S and acquired resistance to protein C
– Compression of IVC
warfarin
- contraindicated during the antepartum period(6-9 weeks embryopathy)
but - safe to commence postpartum and is also compatible with breastfeeding.
Treatment with warfarin should be continued for at least 6 months postpartum for PE.
LFTs in pregnancy
ALP increases during pregnancy
AST,ALT,GGT,Bilirubin,Albumin Decreases during pregnancy.
ALP,Cholesterol,Caeruloplasmin Increases during pregnancy.
Drugs category
Category A:
No evidence of risk to fetus in the first trimester of pregnancy and also in later trimesters.
Category B:
Animal studies have shown adverse effect, but studies in pregnant women have failed to demonstrate a risk to the fetus in any trimester.
Category C:
Animal studies have shown adverse effect on the fetus and there are no studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.
Category D:
Positive evidence of human fetal risk but potential benefits may warrant use of the drug in pregnant women despite potential risks.
Category X:
Studies have demonstrated positive evidence of human fetal risk and the risks involved in use of the drug in pregnant women clearly outweigh potential benefits.
Principles of Management of HELLP syndrome
1) The cornerstone of therapy is delivery. Prompt delivery is indicated if: – pregnancies >34 weeks. – non-reassuring fetal status – Presence of severe maternal disease.
2) Antihypertensives to treat severe HT.
– labetalol,hydralazine,nifedipine.
3) Platelet transfusion if significant maternal bleeding.
4) Opioids for analgesia
Diagnostic criteria for HELLP syndrome(Hemolysis,Elevated Liver enzyme, Low Platelet)
- Haemolysis:
- schistocytes, burr cells, polychromasia on a peripheral blood smear, are diagnostic; however, peripheral blood smears are not routinely performed in clinical practice. Rather, elevated total and indirect (unconjugated) bilirubin (total bilirubin ≥20.5 micromol/L [ ≥1.2 mg/dL]), low serum haptoglobin, and elevated LDH are considered sufficient evidence of haemolysis. - Elevated liver transaminases:
- aspartate transaminase (AST) or alanine transaminase (ALT) ≥70 units/L. - Low platelets:
- severe thrombocytopenia
acute fatty liver of pregnancy
– Acute fatty liver of pregnancy is characterized by microvesicular fatty infiltration of hepatocytes which is unique to human pregnancy.
– Incidence is rare, approximately 1 in 7000 to 1 in 20,000 deliveries.
– More common with multiple gestations and possibly in women who are underweight.
– Typically in the third trimester. The disease is always present before delivery, although it is not always diagnosed prior to delivery.
– Most frequent initial symptoms are nausea or vomiting (approximately 75 percent of patients), abdominal pain (particularly epigastric, 50 percent), anorexia, and jaundice. About one-half of patients have signs of preeclampsia at presentation or at some time during the course of illness.
– Diagnosis is made clinically based upon the setting, presentation and compatible laboratory and imaging results.
– Laboratory tests that are helpful include serum aminotransferases, serum bilirubin, coagulation studies, electrolytes, serum glucose, uric acid level and creatinine, and a white blood cell count.
– Need to exclude HELLP syndrome, which is characterized by hemolysis, elevated liver enzymes and a low platelet count.
– Primary treatment is prompt delivery of the fetus after maternal stabilization.
– Some affected women and their fetuses might have an inherited enzyme deficiency in beta-oxidation that predisposes the mother to this disorder. The most common is G1528C mutation which causes (LCHAD) deficiency.
– Acute fatty liver can recur in subsequent pregnancies, even if the search of LCHAD mutation is negative.
