16 Weeks Pregnant

What’s happening this week

Your baby…

  • measures about 11 cm
  • weighs about 100 grams
  • can hold his head erect
  • has expressions on his face
  • limb movements are becoming more coordinated
  • empties his bladder every 40-45 minutes
  • all organs and structures have formed and a period of simple growth begins.


  • may begin to feel your baby move (particularly if this isn’t your first baby)
  • some women experience headaches due to the changes in blood volume and vacular tone
  • may feel hungrier than usual.

If you have decided to have an amniocentesis, it may be done this week.


Amniocentesis is usually carried out on week 15 or 16 of your pregnancy.  Indications for having this test performed are:

  • If results from earlier blood tests show a high risk of your baby having an abnormality.
  • You have a family history of genetic abnormalities.

What is amniocentesis?

It is a diagnostic test to detect genetic abnormalities such as Spina bifida, Down syndrome and other rare conditions. An amniotic fluid sample is taken from around the baby.

How is it carried out?

A needle is guided by direct ultrasound scan (to ensure no harm to the baby) and will be inserted through the wall of your abdomen.  A sample of amniotic fluid is taken. The doctor will show you your baby’s heartbeat after the test to ensure all is well.  You are advised to rest for 24 hours.  Amniotic fluid contains cells from the fetus. Culture of these cells in a laboratory will determine whether your baby has a genetic abnormality such as Down syndrome. Results can take from 7 days to 3 weeks.

Are there any risks?

A small risk that the procedure can cause miscarriage – 1:100 to 1:200.

What next?  Amniocentesis results

If you decided to have an amniocentesis the results are usually back within 7 – 10 days, and in some areas, a preliminary report may be back as early as 48 hours.  You may feel very relieved, but some parents have results that are worrying.  It’s very important to talk these results through with your LMC or obstetrician.  You may want to go away and talk with your family, your spiritual adviser or just have some time alone.  It’s not often that you have to make an instant decision.  Take the time you need and ask for the help you need.

If your baby is found to have a condition after diagnostic testing, you will be given the opportunity to make choices about either continuing or terminating the pregnancy.

Whatever your choice, support is available.

Jargon busters

Wonder what all those strange abbreviations on your medical notes stand for? All is revealed…

 Alb – Albumin

A protein – protein in your urine could mark a potential problem or an infection like cystitis.

 BP – Blood Pressure

You’ll see two figures in this reading: the top one is the systolic measurement (when your heart pushes the blood through your body) and the lower one is the diastolic pressure (in the pause between heartbeats); a sudden rise in blood pressure could indicate a problem.


Descent, similar to engagemnet, and the more favoured term.  Descent may be measured in 5ths so you may see a number here.

 EDD – Expected Date of Delivery (sometimes EDC, Expected Date of Confinement)

Worked out using the date of your last period and sometimes using ultrasound dating scans.

 Eng – Engagement

When your baby’s head moves down into your pelvis later in pregnancy.

FH – Fetal Heart

Fetal heart rate heard and recorded.

FMF – Fetal Movement Felt

Your baby may manage a good kick during a check up.

Fundus – fundal height

The height the fundus (top of your uterus) has reached in your abdomen is a sign of how many weeks pregnant you are.


Good Fetal movements.

GLU/Glucose… means sugar!

It’s common to find a trace of sugar in your urine, but a high level could mean further tests to see if you are developing diabetes (see Week 14).

Hb – Haemoglobin

The part of the red blood cells that carry oxygen around your body, and which need iron to work well. Levels below 120mm/1 may mean you need extra iron.

LMP – Last Menstrual Period

This date is used to work out when your baby is due.

NAD – No Abnormality Detected

It means everything’s fine.


The position of the lowest part of the baby in relation to points on the mother’s pelvis, primarily assessed by the location of the baby’s back on palpation.

 Pres – Presentation

The way the baby is lying – head up or down, or sideways.


This means swelling. It may be measured by +(mild), ++ (moderate), +++(severe) or Nil (which means none).

 T or Tr – trace

You may see “Tr ketones” or “+ ketones” if there is a small amount of ketones in the urine. Your LMC will explain why this is occurring.