Volume 18 Issue 2 - April 2016 Flashcards
The primary function of peripheral natural killer (pNK) cells is to recognise foreign antigens. These cells are characterised by their surface antigens.
What is the characteristic surface antigen pattern in pNK cells?
CD56dim/CD16- CD56bright/CD16+ CD56dim/CD16+ CD56bright/CD16- CD56-/CD16+
CD56dim/CD16+
Central to the host defense mechanisms, are natural killer cells which play a vital role in the innate immune response. They are subtyped by virtue of their expression of CD56 and CD16 cell surface antigens. Most pNK cells exhibit CD16 but fewer CD56 surface antigens thus they are typically described as CD56dim/CD16+.
The population of cells in the endometrial stroma varies with the time of the menstrual cycle.
What proportion of the leucocyte population of the endometrial stroma during the later secretory phase is made up of uterine natural killer cells?
At least 10% At least 20% At least 30% At least 40% At least 50%
At least 30%
Uterine natural killer (uNK) cells are the predominant leucocyte population of the endometrium and account for at least 30% of the endometrial stroma during the later secretory phase of the menstrual cycle where they are found surrounding the spiral arteries (but not the veins).
A couple are anxious about the risk of their baby being born with an inherited autosomal recessive condition. Their anxiety stems from the fact that their relative recently had a baby with an autosomal recessive condition. They want to know what the most common autosomal recessive condition worldwide is.
What do you tell them?
α-thalassaemia β-thalassaemia Cystic fibrosis Haemophilia Sickle cell disease
β-thalassaemia
The most common autosomal recessive condition worldwide is β-thalassaemia. The most common autosomal recessive condition among Caucasians in Europe is cystic fibrosis. There are currently more than 1000 mutations responsible for cystic fibrosis and the most common is Δ508.
A couple had three IVFs, all of which failed to achieve a pregnancy. On each occasion the woman had a positive pregnancy test but by the time she attended for an ultrasound scan no intrauterine sac was demonstrated. She was therefore labelled as implantation failure.
What is the most common cause of implantation failure in couples like this undergoing IVF?
A very thick endometrium
Chromosome abnormalities in the embryo
Immunological disorders, such as antiphospholipid syndrome
Luteal phase deficiency (in the form of poor support)
Poor-quality embryos
Chromosome abnormalities in the embryo
Aneuploidies are the most frequent cause of spontaneous miscarriages and implantation failure in couples undergoing IVF. Structural chromosome rearrangements occur as a result of simultaneous breakage of chromosomal segments that then rejoin within the same or a different chromosome.
A 30-year-old has been diagnosed with acute kidney injury following an obstetric complication.
What is the most common cause of acute kidney injury in obstetrics?
Antepartum haemorrhage especially placental abruption Drugs such as NSAIDs Postpartum haemorrhage Pre-eclampsia Sepsis
Pre-eclampsia
More than one aetiology is responsible for AKI in pregnancy. Data from audit studies indicate that it complicates 1.4% of obstetric admissions in the UK and that the most common cause is pre-eclampsia. Most cases occur in women without pre-existing renal disease and over 40% go unrecognised by the treating clinical team.
You are part of the team managing a 24-year-old pregnant woman who developed acute kidney injury at 28 weeks of gestation following a road traffic accident.
What will be the pregnancy-specific indication for considering renal replacement in this woman?
Fluid overload refractory to medical management
Hyperkalaemia
Metabolic acidosis
Serum urea >17 mmol/l
Serum urea >17 mmol/l despite medical treatment
Serum urea >17 mmol/l despite medical treatment
The indications for renal replacement therapy in pregnancy mirror those in the nonpregnant population and include metabolic acidosis, hyperkalaemia and fluid overload refractory to medical management. In addition, urea is teratogenic and a serum urea of greater than 17 mmol/l, despite medical management, is a pregnancy-specific indication for renal replacement therapy.
You see a couple in the Gynaecology clinic with subfertility of 18 months’ duration. The woman, who is generally healthy, has a BMI of 24 kg/m2 and is ovulating normally as evidenced by 21-day progesterone test. The man, who is a smoker, has a BMI of 44 kg/m2.
What is the likely impact of his high BMI on their fertility?
Alters lipid content of seminal plasma Associated with hypothermia of the testicles Causes erectile dysfunction Increases libido Production of immature spermatozoa
Causes erectile dysfunction
Obesity can impair fertility in both men and women. In the man, it can contribute to subfertility by causing DNA damage to sperm, decreasing libido and causing erectile dysfunction. In the woman, it alters the follicular environment and leads to oocyte incompetence and suboptimal embryo quality, impairing implantation by negatively influencing the endometrium.
A 30-year-old woman is on the waiting list for IVF treatment and has been found to have a low ovarian reserve.
What is the implication of this to the woman with regards to her IVF?
An increased likelihood of cycle cancellation High miscarriage rates Increased risk of aneuploidy Low pregnancy rates Poor response to gonadotrophins
An increased likelihood of cycle cancellation
A woman’s age remains the single most important factor determining reproductive outcome; ovarian reserve can only predict ovarian response in an assisted reproductive technology cycle. Younger women with low ovarian reserve are more likely to have cycle cancellation caused by poor oocyte yield in IVF, but once the oocytes are retrieved they have almost normal pregnancy rates.
You are seeing a 29-year-old in the clinic for counselling. She has had four midtrimester miscarriages and the last two all followed a failed vaginal cerclage (one a McDonald and the other a Shirodkar). When she was examined at her last clinic visit there was very little vaginal cervix. She is now 6 weeks pregnant.
What would be the approach for minimising the risk of miscarriage in this woman?
Offer a transabdominal cerclage at 10–11 weeks
Offer an abdominal cerclage at this gestation
Repeat McDonald suture at 14 weeks
Repeat Shirodkar suture at 14 weeks
Serial ultrasound scan and insert Shirodkar when cervix is less than 15 mm long
Offer a transabdominal cerclage at 10–11 weeks
Where vaginal cerclages have failed and the vaginal cervix is absent or, as in this case, almost nonexistent, the patient should be offered a transabdominal cerclage. Although an interval suture has advantages over one performed in pregnancy, it’s best to offer it to this patient. The best timing of the procedure is after 10–11 weeks of gestation when first trimester miscarriages from other causes must have occurred. Some practitioners will perform an early anomaly ultrasound scan at 11 weeks before performing the procedure.
What is the estimated successful pregnancy rate following transabdominal cerclage performed by laparotomy at approximately 11 weeks of gestation?
40–50% 50–60% 60–70% 70–80% >80%
> 80%
The successful pregnancy rate for transabdominal cerclage varies depending on the experience of the surgeon and the timing of the procedure (whether it is an interval procedure or it is performed during pregnancy). In the reported series performed during pregnancy, the success rates have been at least 80%; some series report rates as high as 97.6%. The success rates from the laparoscopic approach have varied from 71.4% to 83.3%.
