What screening tests are offered before 14 weeks?
At 9 to 13+6 weeks, blood can be tested for beta-hCG and PAPP-A.
At 11 to 14 weeks a NT ultrasound scan can be performed to measure the space between the skin and spine on the neck.
These tests are to detect chromosomal abnormalities.
An increased subcutaneous space between the skin and the cervical spine on a NT scan is associated with what?
An increased risk of aneuploidy, particularly trisomy 21 (Down syndrome), trisomy 18 (Edwards Syndrome), and trisomy 13 (Patau's syndrome).
What is CVS and why is it carried out?
Chorionic Villus Sampling (CVS) is generally carried out in the first trimester.
The placenta is located by ultrasound scan and a sample of the chorionic villi is taken and analysed for chromosomal abnormalities. The sample is taken transabdominally or through the cervix. Test results take a few days (rapid).
Reasons for CVS include: woman's age, risk of aneuploidy, to determine sex of baby for families with x-related disorders.
Risks: miscarriage (2%), fetal limb abnormality (when done before 10 weeks), infection, cervical damage, haemorrhage, ambiguous results.
What is amniocentesis and why is it carried out?
Amniocentesis is a sample of amniotic fluid that is taken to test for genetic disorders, chromosomal abnormalities, and some infections. Performed between 15 and 18 weeks gestation.
A needle is passed through the abdominal wall into the uterine cavity under ultrasound guidance. ~20mL of amniotic fluid is withdrawn. Examination of liquour for raised levels of alpha fetoprotein (associated with NTDs such as spina bifida), and fetal cells contained in the sample. Fetal cells are cultured. Results take some weeks to obtain. A negative test is only negative for abnormalities looked for, does not necessarily indiciate 'normality'.
Risks: miscarriage (0.5-1%), failure of cells to culture (1:500), damage to baby or cord, infection, SROM or leakage.
Rh neg women require anti-D following procedure.
What is anti-D and why might it be required in pregnancy/after birth?
Anti-D is a blood product that is given (with consent) to prevent maternal antibody production against fetal cells.
If a woman is Rh negative and her baby is Rh positive, the presence of fetal cells in the maternal circulation can induce production of antibodies which can cross the placenta and cause haemolysis in the baby's circulation. Usually problematic in subsequent pregnancies. Anti-D should be given to Rh neg women when fetomaternal isoimmunisation may occur, e.g. after procedures such as CVS, amniocentesis, ECV and birth.
When is a woman routinely screened for antibodies during pregnancy?
At booking, 28 weeks, and 36 weeks.
What blood tests are offered after birth, to a Rhesus negative woman and her baby?
The woman is offered a Kleihauer test, which estimates the number of fetal cells present in the maternal blood.
The cord blood from the baby is tested for blood group and rhesus factor, and a direct Coombs test measures the level of maternal antibodies.
Abortion is the expulsion of products of conception prior to 20 completed weeks of pregnancy. May be spontaneous or induced.
When can an induced/therapeutic abortion be carried out, and what Act is this under?
Abortion can be induced when two certifying consultants agree that there is substantial danger to the woman's life, to her mental or physical health, when there is fetal abnormality, or if the baby will be mentally subnormal.
Governed by the Contraception, Sterilisation and Abortion Act 1977 and the 1961 Crimes Act.
Abortion obtained outside of these requirements is a criminal abortion and is an offence.
What is an implantation bleed?
A small amount of bleeding as the trophoblast embeds into the endometrium. Usually occurs 8-12 days after fertilisation (about when a period would normally be due - may be mistaken for this).
What are three kinds of cervical lesions?
A cervical polyp is a small, fleshy growth attached by a pedicle to the cervix. May have slight blood loss when agitated.
A cervical ectropion is the proliferation of cervical canal columnar epithelium, caused by pregnancy hormones. Reddish area can be visualised. May bleed slightly when agitated. Usually regresses when pregnancy hormones subside.
A cervical cancer is hard, irregular and bleeds easily. This is the most frequently diagnosed cancer in pregnancy and has a poor prognosis. Frequently women are advised to terminate their pregnancy to assist chances of survival.
A woman at 11 weeks rings and tells you she is bleeding. What do you say and do?
- - How much blood loss is there?
- - When did it start?
- - What colour is the loss, and is there any pain associated with the bleeding?
- - Is the bleeding definitely coming from the vagina and not the rectum?
- - Is she at home, and who is with her?
- - Ask her to keep all pads and items with blood on.
Scant red or brown loss is threatened miscarriage
. Advise to rest, book for non-urgent USS, and ask her to phone you if bleeding becomes heavier or has clots in it.
If bleeding heavily, she needs to be seen directly. If she is alone, she should call an ambulance. If close, go directly to her home, otherwise talk to the emergency department and the ambulance service. If bleeding continues to be heavy, this is an inevitable abortion/miscarriage
. Woman needs to be admitted to hospital for heavy bleeding, IV fluids commenced via a large bore cannula, monitor vital signs, be prepared for resuscitation.
DO NOT perform digital examination. Visualise the cervix (if required) using a speculum.
USS can be used to assess viability of the baby. Care, support and information are vital.
What is ectopic pregnancy? What are possible causes?
Ectopic pregnancy occurs when a fertilised ovum implants outside the uterine cavity. Incidence is 1:150 pregnancies.
95% of ectopic pregnancies occur in the uterine tubes (tubular pregnancy), but it also may occur in the abdominal cavity or the ovary.
- - delayed in transport of zygote along fallopian tube
- - malformation of fallopian tubes
- - scarring or damage to fallopian tubes
- Risks for ectopic pregnancy:
- - previous ectopic pregnancy
- - uterine tube surgery
- - PID
- - endometriosis in uterine tubes
- - pelvic surgery causing adhesions
- - use of hormonal drugs to cause ovulation (e.g. clomiphene) which may affect motility of tubes
- - IUDs
- - IVF pregnancy
- - post-coital contraception
- - STD such as Chlamydia
How is an ectopic pregnancy diagnosed? What should you do if rupture is suspected?
- - Woman may not experience amenorrhoea
- - Early pregnancy bleeding
- - Pain as tube distends to accommodate growing fetus
- - May be confused with PID
- - Nausea, diarrhoea, pain on defacation
- - Diagnostic sign is an empty uterus on USS
of ectopic pregnancy diagnosed prior to rupture is managed with use of Methotrexate. Only available to women with minimal pain/bleeding who are haemodynamically stable.
Rupture usually occurs between 7-10 weeks gestation, depending on site of implantation (if in tube, may be 5-7 weeks; if in ampulla, may be 10 weeks).
- - considerable haemorrhage into intraperitoneal space
- - intense abdominal pain
- - pain referred to shoulder (if blood tracks towards diaphragm)
- - tender abdomen
- - pale and shocked
- - examination of uterus/cervix will be intensely painful
- - admission to hospital
- - large guage cannula sited
- - bloods taken for group and cross-match
- - IV fluids
- - resuscitation if required
- - transfer to theatre
- - laproscopic salpingotomy may be performed, or is woman deeply shocked, laparotomy may be performed