100 Cases in Obstetrics & Gynaecology Flashcards

Question

What are the diagnostic tests used for Down's syndrome in-utero?

Answer 1

**Chorionic villous sampling:** * Performed 11 to 14 weeks’ gestation * Ultrasound guidance * Sample of placental tissue collected generally using needle inserted through the abdominal wall * Small risk of miscarriage (about 1 per cent) associated with the procedure * Inconclusive result in 1 per cent of cases (so amniocentesis then required) **Amniocentesis:** * Performed any time from 15 to 16 weeks’ gestation * Ultrasound guidance * Sample of amniotic fluid collected using needle inserted through the abdominal wall * Small risk of miscarriage (about 1 per cent) **Cell-free fetal DNA:** * This recently developed non-invasive diagnostic test detects cell-free fetal DNA in a sample of maternal blood from 10 weeks’ gestation. It is used to identify the common trisomies (21, 18, 13) and fetal gender

Answer 2

**Fetal:** * Low birth weight * Neonatal anaemia * Cognitive impairment **Maternal:** * Antenatal symptoms (fatigue, fainting, dizziness) * Peripartum complications (haemodynamic compromise from extensive blood loss)

Answer 3

**Maternal blood:** * Bloody show (blood-stained cervical mucous from ruptured cervical vessels) * Bleeding placenta previa * Placental abruption * Cervical ectropion * Infection (e.g. candida) **Fetal blood:** * Vasa previa

Answer 4

* Predictable timing of delivery (unless labour occurs prior to the planned date of caesarean) * Avoidance of the need for an emergency caesarean, which has higher complication rates * Avoidance of the possibility of birth trauma to the baby, although the studies do not show a difference in incidence of hypoxic ischaemic encephalopathy or intra- cranial haemorrhage * Reduction in the chance of pelvic floor weakness (although this occurs in part due to pregnancy itself and therefore incontinence and prolapse are not completely avoided by caesarean section) * Lower rate of immediate postpartum haemorrhage * Lower rate of injury to the vagina and perineum

Answer 5

* Increased rate of admission of baby to neonatal care unit * Greater pain following abdominal surgery * Possibility of intraperitoneal trauma to bowel or bladder at surgery * Increased risk of wound infection * Possibility of thrombosis (although this is minimized by the use of heparin prophylaxis) * Longer hospital admission * Increased likelihood of needing caesarean section in a subsequent pregnancy * Very small increase in chance of hysterectomy for postpartum haemorrhage or of cardiac arrest

Answer 6

* Women who do not want to give birth naturally due to mental health or anxiety problems should be referred to specialist for support and counselling * If despite support and counselling the woman still insists on caesarean section, it may be offered

Answer 7

**Maternal:** * Diabetes * Infection (e.g. parvovirus, listeria) * Thrombophilia (e.g.antiphospholipidsyndrome) **Fetal:** * Chromosomal abnormality (e.g.trisomy) * Other genetic abnormality (e.g. Gaucher’s disease) * Haemolytic disease * Cord incident (e.g. ‘knot’ in cord) **Placental:** * Placental abruption * Uteroplacental insufficiency (e.g. secondary to pre-eclampsia) * Postmaturity **Unexplained**

Answer 8

* Fetal bradycardia on CTG is defined as fetal heart rate dropping \<100/min * Though in many cases the cause is unknown, common causes include: 1. Placental abruption 2. Uterine rupture 3. Maternal hypotension (e.g. after epidural insertion) 4. Bleeding vasa praevia

Answer 9

**Rule of 3:** 1. If the deceleration has not recovered at 3 min call for help. 2. If the deceleration has not recovered at 6 min transfer to theatre and prepare for immediate delivery. 3. If the deceleration has not recovered at 9 min deliver immediately by category one (‘crash’) caesarean section (if immediate instrumental vaginal delivery is not pos- sible). This will usually involve general anaesthetic unless an effective spinal anaesthetic is achievable by an experienced anaesthetist in a similar time.

Answer 10

**Advantages:** * Reduced risk of stillbirth associated with prolonged pregnancy – the relative risk of stillbirth from induction of labour after 41 weeks (versus expectant management) is 0.30. * Some women express the wish to deliver soon after 40 weeks because of discomfort, anxiety or social reasons. **Disadvantages:** * Uterine hyperstimulation (1–5 percent). * Failed induction (15 percent) – may require repeat induction process or caesar- ean section. * Induction of labour can be a prolonged process – sometimes taking more than 24 h for labour to be established. * Approximately 500 women need to undergo induction of labour to prevent one baby death. * There is some evidence that induced labour is associated with greater analgesia requirement than spontaneous labour.

Answer 11

Urate levels (in mmol/L) should be no higher than the current gestational week

Answer 12

* Copper coil * Contraceptive vaginal ring * Contraceptive implant * Contraceptive depot injection * Levonorgestrel-containing intrauterine system (IUS)

Answer 13

* Has she been missing any pills? * Has she taken any other medication which might interfere with the COCP (e.g. anti- biotics, enzyme inducers)? * Has she had any intercurrent illnesses causing diarrhoea or vomiting? * Has she ever had any sexually transmitted infections, or been investigated for this? * How many sexual partners has she had in the last 3 months? * Has she recently changed the COCP that she uses?

Answer 14

**COCP-related causes:** * Poor compliance * Intercurrent infection causing poor pill absorption * Drug interactions, reducing the COCP efficacy * Inadequate oestrogen component for that woman * Pregnancy **Unrelated causes:** * Cervical ectropion * Cervical carcinoma * Sexually transmitted infection – chlamydia, gonorrhoea, trichomonas * Candidal vaginitis * Cervical or endometrial polyp * Bleeding disorder (rare)