Obstetrics Flashcards
What % of couples have a problem with conceiving?
85% will conceive within a year of regular unprotected sex. 1 in 7 couples will struggle to conceive naturally.
When are investigations done for infertility?
Investigation and referral for infertility should be initiated after the couple has been trying to conceive without success for 12 months. This can be reduced to 6 months if the woman is older than 35, as her ovarian stores are likely to be already reduced and time is more precious.
List causes of infertility
Sperm problems (30%)
Ovulation problems (25%)
Tubal problems (15%)
Uterine problems (10%)
Unexplained (20%)
40% of infertile couples have a mix of male and female causes.
Suggest investigations for infertility.
Initial investigations, often performed in primary care:
Body mass index (BMI) (low could indicate anovulation, high could indicate PCOS)
Chlamydia screening
Semen analysis
Female hormonal testing (see below)
Rubella immunity in the mother
Female hormone testing involves:
Serum LH and FSH on day 2 to 5 of the cycle
Serum progesterone on day 21 of the cycle (or 7 days before the end of the cycle if not a 28-day cycle).
Anti-Mullerian hormone
Thyroid function tests when symptoms are suggestive
Prolactin (hyperprolactinaemia is a cause of anovulation) when symptoms of galactorrhea or amenorrhoea
Suggest treatments for anovulation.
Weight loss for overweight patients with PCOS can restore ovulation
Clomifene may be used to stimulate ovulation
Letrozole may be used instead of clomifene to stimulate ovulation (aromatase inhibitor with anti-oestrogen effects)
Gonadotropins may be used to stimulate ovulation in women resistant to clomifene
Ovarian drilling may be used in polycystic ovarian syndrome
Metformin may be used when there is insulin insensitivity and obesity (usually associated with PCOS)
Outline how sperm problems are managed
Surgical sperm retrieval
Surgical correction of an obstruction in the vas deferens may restore male fertility.
Intra-uterine inseminsation
Intracytoplasmic sperm injection (ICSI)
Donor insemination with sperm from a donor is another option for male factor infertility.
How is a sperm sample taken?
Abstain from ejaculation for at least 3 days and at most 7 days
Avoid hot baths, sauna and tight underwear during the lead up to providing a sample
Attempt to catch the full sample
Deliver the sample to the lab within 1 hour of ejaculation
Keep the sample warm (e.g. in underwear) before delivery
What is measured in a sperm sample?
Semen volume (more than 1.5ml)
Semen pH (greater than 7.2)
Concentration of sperm (more than 15 million per ml)
Total number of sperm (more than 39 million per sample)
Motility of sperm (more than 40% of sperm are mobile)
Vitality of sperm (more than 58% of sperm are active)
Percentage of normal sperm (more than 4%)
What terms are used for sperm cell numbers?
Normospermia (or normozoospermia) refers to normal characteristics of the sperm in the semen sample.
Oligospermia (or oligozoospermia) is a reduced number of sperm in the semen sample. It is classified as:
Mild oligospermia (10 to 15 million / ml)
Moderate oligospermia (5 to 10 million / ml)
Severe oligospermia (less than 5 million / ml)
Cryptozoospermia refers to very few sperm in the semen sample (less than 1 million / ml).
Azoospermia is the absence of sperm in the semen.
What are the features of OHSS?
Early OHSS presents within 7 days of the hCG injection. Late OHSS presents from 10 days onwards.
Features of the condition include:
Abdominal pain and bloating
Nausea and vomiting
Diarrhoea
Hypotension
Hypovolaemia
Ascites
Pleural effusions
Renal failure
Peritonitis from rupturing follicles releasing blood
Prothrombotic state (risk of DVT and PE)
How is OHSS managed?
Oral fluids
Monitoring of urine output
Low molecular weight heparin (to prevent thromboembolism)
Ascitic fluid removal (paracentesis) if required
IV colloids (e.g. human albumin solution)
What is the bagel sign?
Ectopic pregnancy
What hcg represents an ectopic pregnancy?
A rise of less than 63% after 48 hours may indicate an ectopic pregnancy. When this happens the patient needs close monitoring and review.
How are ectopic pregnancies managed?
There are three options for terminating an ectopic pregnancy:
Expectant management (awaiting natural termination)
Medical management (methotrexate)
Surgical management (salpingectomy or salpingotomy)
Criteria for expectant management:
Follow up needs to be possible to ensure successful termination
The ectopic needs to be unruptured
Adnexal mass < 35mm
No visible heartbeat
No significant pain
HCG level < 1500 IU / l
Define gravida
Gravida (G) is the total number of pregnancies a woman has had
Define para
refers to the number of times the woman has given birth after 24 weeks gestation, regardless of whether the fetus was alive or stillborn
What is nulliparous, primiparous and multiparous?
Nulliparous (“nullip”) refers to a patient that has never given birth after 24 weeks gestation
Primiparous technically refers to a patient that has given birth after 24 weeks gestation once before (see below)
Multiparous (“multip”) refers to a patient that has given birth after 24 weeks gestation two or more times
What are the trimesters?
The first trimester is from the start of pregnancy until 12 weeks gestation.
The second trimester is from 13 weeks until 26 weeks gestation.
The third trimester is from 27 weeks gestation until birth.
What vaccines are given in pregnancy?
Whooping cough (pertussis) from 16 weeks gestation
Influenza (flu) when available in autumn or winter
What vaccines are avoided in pregnancy?
MMR and live vaccines
What are some milestones for pregnancy?
Between 10 and 13 + 6 -Dating scan
16 week antenatal appointment
Between 18 and 20 + 6 - anomaly scan
Oral glucose tolerance test in women at risk of gestational diabetes (between 24 – 28 weeks)
Anti-D injections in rhesus negative women (at 28 and 34 weeks)
Ultrasound scan at 32 weeks for women with placenta praevia on the anomaly scan
Serial growth scans are offered to women at increased risk of fetal growth restriction
What tests are done during antenatal testing?
Discuss plans for the remainder of the pregnancy and delivery
Symphysis–fundal height measurement from 24 weeks onwards
Fetal presentation assessment from 36 weeks onwards
Urine dipstick for protein for pre-eclampsia
Blood pressure for pre-eclampsia
Urine for microscopy and culture for asymptomatic bacteriuria
Discuss advice given to pregnant women.
Take folic acid 400mcg from before pregnancy to 12 weeks (reduces neural tube defects)
Take vitamin D supplement (10 mcg or 400 IU daily)
Avoid vitamin A supplements and eating liver or pate (vitamin A is teratogenic at high doses)
Don’t drink alcohol when pregnant (risk of fetal alcohol syndrome)
Don’t smoke (smoking has a long list of complications, see below)
Avoid unpasteurised dairy or blue cheese (risk of listeriosis)
Avoid undercooked or raw poultry (risk of salmonella)
Continue moderate exercise but avoid contact sports
Sex is safe
Flying increases the risk of venous thromboembolism (VTE)
Place car seatbelts above and below the bump (not across it)
When must pregnant women stop flying?
The RCOG advises flying is generally ok in uncomplicated healthy pregnancies up to:
37 weeks in a single pregnancy
32 weeks in a twin pregnancy
After 28 weeks gestation, most airlines need a note from a midwife, GP or obstetrician to state the pregnancy is going well and there are no additional risks.