Histopathological Examination of Products of Conception
Why Ask Me to Read This Leaflet Now After My Pregnancy Loss?
We are sorry about your pregnancy loss and appreciate this must be a difficult time for you. We are talking to you now to avoid further distress. This leaflet aims to give you practical information about the histological examination.
The tissue from the pregnancy is often called the ‘products of conception’. This is usually made up of the afterbirth (placenta), the lining of the womb and blood clot. It is important that tissue from your pregnancy is examined visually and under the microscope.
Sometimes when products of conception are examined visually, an embryo or fetus (developing baby) is found. It is not necessary to examine the embryo or fetus further. However, very occasionally small amounts of fetal material are revealed under the microscope.
Why Do You Need to Examine the Products of Conception?
There are important reasons for carrying out a histological examination.
a. Ectopic Pregnancy. If you had an ectopic pregnancy, the histological examination will confirm that a pregnancy was present in the tube and therefore rule out any other problem such as a cyst or a growth
b. Rarely, a fertilised egg will not develop into a fetus and the cells multiply in an uncontrolled way. This is called a molar pregnancy or a partial molar pregnancy. The molar tissue is abnormal to the naked eye and may have been suspected by its appearance on an
a. ultrasound scan or an unusually high hormone level in the blood. A partial molar is much more difficult to detect and can only be determined by examination under a microscope.
If molar or partial molar tissue is found then you will be followed up. Close follow-up is required to prevent uncontrolled tissue formation in the future.
b. Histological examination may provide evidence that the fetus was within the womb.
What Happens at a Histological Examination?
There are two stages to a histological examination. First a naked eye examination of the products of conception is carried out by a medically trained doctor known as a pathologist. At this stage material is selected for the second stage, microscopic examination. If there is a recognisable fetus or fetal material, this will not be selected for microscopic examination but will be kept on one side.
The material (samples) selected for microscopic examination are normally each about 20mm square and 4mm thick (about the size of a postage stamp). It is usual to take between two and four further samples. This may constitute the whole of the products of conception (excluding any recognisable fetus).
Each sample is placed into a small plastic box and then treated with chemicals to remove the water and to replace it with wax. Once the tissue is embedded in solid wax it is known as a block. Using a special machine called a microtome with a very sharp knife, a slice or thin section is then cut from each block. The sections are extremely thin (approximately ten times thinner than a human hair). Each section is placed
onto a glass slide and stained with special dyes to enable the cells and other tissue components to be examined using a microscope. These techniques are no different from those used on all specimens sent for histological examination.
Results of the Histological Examination
When the examination is complete, the results will be sent to your consultant obstetrician and gynaecologist. The consultant will write to your general practitioner enclosing a copy of the results.
You may wish to contact your GP approximately eight weeks after your pregnancy loss to discuss the results of the histological examination.
If an ectopic pregnancy has not been excluded or molar tissue has been found, you will be contacted by the hospital for further investigations.
What Happens to the Products of Conception?
Any products of conception, not sampled for histological examination, including the fetus where one was identified by the naked eye, will be disposed of legally and respectfully.
Before this happens, you will be asked to sign a consent form allowing us to dispose of the products of conception and informing us whether or not you wish to be involved.
In a very small number of cases, fetal tissue may only be detected by histological examination. If this is the case and you have previously requested it on the consent form, then the
material embedded in wax will be reunited with the rest of the specimen prior to disposal. Fetal tissue present in sections or slides will, with your consent, be kept by the hospital as part of the medical records. Slides are kept for a period of 30 years after which time they will be legally and respectfully disposed of.
You may withhold your consent to the hospital retaining slides in this way and have the slides released to you with all other fetal tissue.
A separate information leaflet on the disposal of fetal tissue is available with details of specific requirements.
USEFUL NUMBERS
Child Bereavement UK
Clare Charity Centre, Wycombe Road, Saunderton, Buckinghamshire HP14 4BF
Telephone: 01494 568900
Email: support@childbereavementuk.org
Web: www.childbereavementuk.org
Support, information and resources for bereaved families and for professionals.
The Miscarriage Association
17 Wentworth Terrace, Wakefield WF1 3QW
Telephone: 01924 200799 (Mon to Fri, 9am-4pm)
Web: www.miscarriageassociation.org.uk
Support and information for those affected by pregnancy loss. Network of support groups and telephone contacts throughout the UK.
Cruse Bereavement Care
Web: www.cruse.org.uk
Support for bereaved by death, in any way, whatever their age, nationality or belief. Help includes counselling, bereavement support and advice or information on practical matters.
Ectopic Pregnancy Trust
Web: www.ectopic.org.uk
Support and information for people who have been affected by an ectopic pregnancy.
Kate Boxall - Midwife for Bereavement Services
The Princess Alexandra Hospital NHS Trust
Hamstel Road, Harlow, CM20 1QX
Telephone: 01279 962694
Web: www.pah.nhs.uk