Chapter 6: US In Pregnancy And Prenatal Screening Flashcards
ULTRASOUND IN PREGNANCY AND PRENATAL SCREENING. You are a trainee intern in general practice seeing Eleanor, a 35-year-old G2P1 Pākehā woman who is 9 weeks pregnant. Eleanor requests your advice about prenatal testing for chromosomal abnormality. Her previous pregnancy was uncomplicated with a normal vaginal delivery at 40 weeks of a healthy male infant. Which of the following options has the greatest SENSITIVITY when screening for Trisomy 21 (Down Syndrome)?
Second trimester serum screening (MSS2)
Maternal karyotype
Non Invasive Prenatal Screening (NIPS)
First trimester combined screening (MSS1)
Nuchal translucency scan
Morphology scan at 18-20 weeks
Non Invasive Prenatal Screening (NIPS)
Very sensitive but not specific - not funded either
ULTRASOUND IN PREGNANCY AND PRENATAL SCREENING. You are a trainee intern in birthing suite with Nancy, a 32 year old New Zealand European woman, G1P0, who is 32 weeks’ gestation. Nancy has just been brought into hospital by ambulance after she was involved in a car accident. She has seatbelt bruising across her lower abdomen and some mild abdominal pain. She has had no vaginal bleeding. She has no other injuries. Her blood group is O negative. You arrange for an urgent ultrasound (which is normal), a CTG (reassuring) and an urgent maternal Kleihauer test (negative). Of the following options, which of the following statements to her about anti D administration is MOST APPROPRIATE?
A dose of 625 IU of anti D should be given
Anti D does not need to be given as there has been no vaginal bleeding
Anti D does not need to be given as the Kleihauer test is negative
Her husband’s blood group should be checked and if he is Rhesus negative, 625IU of Anti D should be given
Her husband’s blood group should be checked and if he is Rhesus positive then 250IU of anti D should be given.\
A dose of 625 IU of anti D should be given.
(NB we don’t check partners blood group routinely, paternity is not always true, however if he was Rh negative that would mean baby is Rh negative)
Kleihauer tests for fetal blood in mums blood, however we still give.
ULTRASOUND IN PREGNANCY AND PRENATAL SCREENING. You are a trainee intern in a general practice with Penny, a 24 year old primigravid New Zealand woman of Samoan ethnicity who is 5 weeks pregnant. As both she and her husband are blood donors, she knows she is rhesus negative, and her husband is rhesus positive. Penny asks you when she might require Anti D injections in her pregnancy. From the options provided, which statement is CORRECT regarding Anti D administration?
She will definitely need Anti D at birth
If she has an antepartum haemorrhage, a dose of 250IU of anti D will be given
She will require Anti D if she has an amniocentesis or chorionic villus sampling
As this is her first pregnancy, she will not be isoimmunised yet and so Anti D is not required.
She will require Anti D if she has NIPS free foetal DNA testing for Down Syndrome
She will require Anti D if she has an amniocentesis or chorionic villus sampling
ULTRASOUND IN PREGNANCY AND PRENATAL SCREENING. You are a trainee intern at an antenatal clinic with Kara, a 34 year old primigravid wahine Māori who is 34 weeks pregnant. When you see Kara her blood pressure is 125/80 and her urinalysis is negative for protein and glucose. You measure the fundal height at 30cm. The lie is longitudinal and the presentation cephalic. Kara’s baby’s movements have been reduced today. The fetal heart is heard and a CTG is normal. Your supervising registrar confirms your examination findings. Which of the following actions and justification is MOST appropriate?
Abdominal ultrasound (for growth measurements, liquor volume and Doppler blood flow measurements)
Blood for viral serology (as fetal infection likely)
Blood for group and cross match (as caesarean section required)
Vaginal examination (as induction of labour required)
Abdominal ultrasound (to confirm fetal morphology)
Abdominal ultrasound (for growth measurements, liquor volume and Doppler blood flow measurements)
30cm is a small fundal height for 34 weeks
ULTRASOUND IN PREGNANCY AND PRENATAL SCREENING. You are a trainee intern working in general practice seeing Frances, a 40 year old G2P1 Pākehā woman and her wife. Frances is 8 weeks pregnant in her second pregnancy. You discuss screening tests for Down syndrome and that at age 40 Frances has a 1 in 100 chance of her baby being affected by Down syndrome. They have seen advertising for NIPS – Non Invasive Prenatal Screening. Frances has read that NIPS is ‘over 99% accurate’. Frances’ wife is a biostatistician and asks you detailed questions about NIPS as a screening test. Which of the following statements is CORRECT?
The sensitivity of the NIPS test is not impacted by the prevalence of a condition i.e. it would be the same in Frances at age 40 as it would be in a woman age 30.
The specificity of the NIPS testing will be reduced because Frances is 40 and at age 40 she has an increased chance of having a baby affected by Down Syndrome.
The sensitivity of the NIPS testing will be increased because Frances is 40 and at age 40 she has an increased chance of having a baby affected by Down Syndrome.
The positive predictive value of the NIPS test will be reduced in Frances (compared with a 30 year old woman) because Frances has an increased chance of having a baby affected by Down Syndrome
The positive predictive value of the NIPS test is not impacted by the prevalence of a condition i.e. it would be the same in Frances at age 40 as it would be in a woman age 30
The sensitivity of the NIPS test is not impacted by the prevalence of a condition i.e. it would be the same in Frances at age 40 as it would be in a woman age 30.
sensitivty + specificity not affected by prevalence
ULTRASOUND IN PREGNANCY AND PRENATAL SCREENING. You are a trainee intern in antenatal clinic seeing Dharshani, a G2P1 New Zealander of Indian ethnicity who is 36 weeks’ gestation. In her previous pregnancy she required a caesarean section for fetal distress in early labour and her son weighed 2kg and was admitted to the neonatal unit with hypoglycaemia. This pregnancy, Dharshani has taken prophylactic aspirin. Dharshani had an ultrasound scan done immediately prior to her clinic appointment. The ultrasound showed an EFW of 1.8kg with an abdominal circumference on the 1st centile, reduced liquor volume and the umbilical artery Doppler showed reversed end-diastolic flow. A CTG shows a baseline of 140 beats per minute with absent variability but no decelerations. Dharshani is not having any contractions. Which of the following options should be the next step in management?
Administer two doses of steroids 24 hours apart and then do a caesarean section.
Immediate caesarean section
Admit for twice daily CTGs. If they are abnormal, do a caesarean section.
Administer two doses of steroids 24 hours apart and then an induction of labour
Admit and repeat the CTG in 6 hours. If it is abnormal, do a caesarean section.
Fetal Scalp pH
Immediate caesarean section
ULTRASOUND IN PREGNANCY AND PRENATAL SCREENING. You are a trainee intern at an antenatal clinic seeing Geeta, a 36 year old primigravid New Zealander of Indian ethnicity who is 37 weeks gestation. She has not felt fetal movements for eight hours and has had some abdominal and back pain. Her blood pressure is 130/90. On abdominal examination the fundal height is 32cms, and the fetal heart cannot be heard with the clinic Sonicaid Doppler. The maternal pulse is 100. Which of the following is the most important investigation to arrange?
Kleihauer Test
Pregnancy ultrasound
Measure her temperature
A CTG
Full Blood Count
Urine Protein: Creatinine ratio
Pregnancy ultrasound
ULTRASOUND IN PREGNANCY AND PRENATAL SCREENING. You are a trainee intern in an antenatal clinic reviewing Leila, a 32 year old primigravid Pākehā woman and her partner. Leila is 17 weeks pregnant and first booked for pregnancy care 2 weeks ago. As it was too late for MSS1 screening to be done, Leila had MSS2 screening done, along with her booking blood tests. The results of the MSS2 have come back reporting a raised alpha-feto protein level, indicating that Leila’s baby has an increased chance of a neural tube defect. Which of the following is the next action that you should recommend for Leila?
Termination of pregnancy
Repeat maternal blood testing for alpha-feto protein
Amniocentesis
Chorionic villus sampling (CVS)
A fetal morphology scan
A fetal morphology scan
ULTRASOUND IN PREGNANCY AND PRENATAL SCREENING. You are a trainee intern in an antenatal clinic with Penina, a 32 year old primigravid Samoan woman and her husband. Penina is 15 weeks pregnant. She missed the window for MSS1 screening as she was on holiday. You discuss the option of 2nd trimester maternal serum screening with Penina and her husband. Which of the following disorders is 2nd trimester maternal serum screening MOST sensitive in detecting?
Cardiac anomalies
Trisomy 21
Spina bifida
Klinefelter’s Syndrome (XXY)
Cystic fibrosis
Trisomy 21
ULTRASOUND IN PREGNANCY AND PRENATAL SCREENING. You are a trainee intern working in general practice seeing Georgina, a 32 year old primigravid Māori lawyer who is 9 weeks pregnant. You offer her first trimester combined screening (MSS1). Which of these following options is the MOST IMPORTANT ANALYTE in the first trimester serum screen?
PAPP-A
Inhibin A
Alpha-feto-protein
Alpha HCG
Unconjugated oestriol
PAPP-A
ULTRASOUND IN PREGNANCY AND PRENATAL SCREENING. You are a trainee intern working in a general practice seeing Angela, a 27 year old primigravid American woman who is now 13 weeks pregnant. You had seen Angela 3 weeks earlier and offered her a first trimester combined screen. The results have come back reporting the risk for Trisomy 21 is 1 in 250 which is classed as ‘increased chance’. You discuss the results with Angela and offer her referral to see a maternal fetal medicine specialist. Angela is worried that invasive tests might cause a miscarriage as this pregnancy was conceived after 3 cycles of IVF. She asks you what the specialist is likely to recommend. As Angela is not a New Zealand resident, she needs to pay for all of her medical care. She has comprehensive medical insurance. From the following options, what is the MOST LIKELY management to be offered initially?
Consideration of termination of pregnancy by prostaglandin therapy
Consideration of termination of pregnancy by suction curettage
Non Invasive Prenatal Screening - NIPS
A detailed morphology scan at 18-20 weeks followed by a cardiac echo at 24 weeks
Chorionic villus sampling (CVS)
2nd trimester maternal serum screening
NIPS
and then diagnostic is still required
