Your baby is now officially an embryo and is about the size of a poppy seed.
Please visit www.nhs.uk/conditions/pregnancy-and-baby/4-weeks-pregnant/ for more information.
Related links
ARC (Antenatal Results & Choices)
The Down's Syndrome Association
SOFT Association - help for Patau's & Edwards' Syndrome
CLAPA ( Cleft lip & palate association)
TAMBA (Twins and Multiple Birth association)
BPAS (British Pregnancy Advisory Service)
Testing and screening
At your first booking appointment your community midwife will discuss and offer you a range of screening tests. The screening tests offered are to help identify any health problems that you may have or that could affect your baby, and may include blood tests and ultrasound scans.
Information on screening tests for you and your baby is available digitally from Public Health England here , and from the QR Code below.
This information is available in 12 different languages, easy read and MP3 audio files.
A screening animation for pregnant women and parents with newborn babies is available here .
Screening is optional and we understand choosing to have the screening tests is a personal choice - you do not have to accept any of the tests offered, however we would like you to understand the purpose of tests so you can make an informed choice. Please ask if you do not understand any of the information provided.
Some of the screening tests for Downs, Edwards and Patau syndrome , sickle cell disease and thalassaemia may lead to difficult decisions and choices of whether to have a diagnostic test. Some tests are invasive and on rare occasions may lead to a miscarriage. You may also need to decide whether you want to continue the pregnancy, depending on the risks described by the test results. Your midwife team or consultant can support you with this decision making.
Some of the screening tests can only be offered in early pregnancy.
Ultrasound scans
It is recommended in England that all women are offered a minimum of two ultrasound scans during their pregnancy. You will be offered an early pregnancy scan, which is usually performed between eight weeks and 14 weeks + 1 day of pregnancy.
The purpose of the scan is to assess how many weeks' pregnant you are, how many babies you are having and to check on your baby's wellbeing.
The early pregnancy scan leaflet can be accessed here .
Between 18+0 and 20+6 weeks pregnant you will be offered an anomaly scan, further information can be accessed here .
Group B Strep (GBS)
GBS is a common bacterium (bug) which is carried in the vagina and rectum of 2 - 4 in 10 women (20 – 40%) in the UK. GBS is not a sexually transmitted disease and most women carrying GBS will have no symptoms.
Carrying GBS is not harmful to you, but it can affect your baby around the time of birth. It can sometimes be found during pregnancy when you have vaginal or rectal swabs or a urine test.
GBS can occasionally cause serious infection in newborn babies and, very rarely, during pregnancy and before labour.
Information on GBS is now available in 14 new languages - Arabic, Bengali, Chinese, French, Hebrew, Latvian, Lithuanian, Polish, Portuguese, Punjabi, Romanian, Somali, Urdu and Welsh - the translated leaflet can be accessed here .
Genital herpes and cold sores in pregnancy
Genital herpes is a common sexually transmitted infection caused by the herpes simplex virus (HSV). There are two types, HSV-1 and HSV-2, both of which can cause infection in the genital and anal area (genital herpes). Herpes simplex can also occur around the mouth and nose (cold sores) and fingers and hand (herpetic whitlows).
Information on genital herpes in pregnancy from the Royal College of Obstetricians and Gynaecologists can be accessed here and additional information on cold sores in pregnancy is here .
