18 Weeks Pregnant

What’s happening this week

Your baby…

  • measures around 12cm
  • weighs around 190 grams
  • ears move to their final position and stand out from the head
  • bones are continuing to ossify
  • a white waxy substance called vernix protects the baby which helps delicate skin from being chapped or scratched
  • pads on the fingers and toes are formed and fingerprints are developing.


  • you may feel faint or dizzy if you stand up suddenly due to adjustments in your new circulatory patterns
  • may feel a little short of breath.

You should be told the results from all the tests you’ve had even if everything’s fine. Ask your LMC – sometimes routine normal results get tucked away in your notes without you noticing!

Group Strep B

As many as 40% of pregnant women carry Strep B bacteria in their vagina – you may not even know it, as the bacteria don’t usually cause problems or symptoms. If your baby catches the infection, he could become seriously ill. Your baby is more likely to develop a Strep B infection if:

  • you have previously had a baby infected with Strep B
  • you go into labour before 37 weeks of pregnancy
  • your waters break before 37 weeks (with or without other signs of labour)
  • your waters break more than 18 to 24 hours before you have your baby
  • you have a raised temperature during labour
  • Strep B has been found in your urine during this pregnancy.

As Strep B is a normal organism for many women it cannot be eradicated by taking antibiotics by mouth. If Strep B is found in your urine or vagina however, it will be treated. In labour you may be given intravenous antibiotics from the start of your labour or from when your waters break (whichever comes first) until your baby is born, to prevent infections in your baby.

I’ve been told my blood pressure is high

Your blood pressure is taken at every antenatal visit because a rise in pressure can be a warning sign of potential problems. However, a slight rise at one visit isn’t a cause for worry – being nervous, rushing to an appointment, worrying about something at work, all of these can send your blood pressure up. You may be told to take things easy for a while, and you may find that things are back to normal at your next visit.

If you develop symptoms such a sudden onset of vomiting, headaches, visual disturbance, chest pains and swelling don’t hesitate to call your LMC.

Standing at work

If you need to stand for long periods at work, try these tips to keep you as comfortable as possible:

  • Stand with knees relaxed
  • Try to stand upright – no slouching!
  • Keep your weight evenly distributed
  • Wear comfortable shoes and clothes
  • Wriggle your toes
  • Wear support stockings – rather than tights, which can increase your risk of developing thrush; they will help prevent varicose veins, too.
  • Move as much as possible – it helps to avoid stiffness and gets your circulation working well.
  • Take regular breaks.

Clothes to suit your changing figure

Just because you’re pregnant, it doesn’t mean you have to wear a tent! There’s a wide range of maternity clothes available in stores and online. Don’t rush out and buy too many outfits at this stage though. You’ve still got some growing to do, and you can’t predict how that growing will go!

What may be comfortable now, may not be comfortable later, and maternity clothes can be expensive when you consider they’re worn for such a short time. Borrow where you can, and look out for second-hand bargains to see you through the next couple of months.

Twins or more?

Approximately 845 sets of twins and 10 sets of triplets are born every year in New Zealand. Quads and quins are rare. The chance of multiple pregnancies increases with age, if there is a history of twins in your own or your partner’s family, if you have taken a fertility drug, or conceived through in vitro fertilization (IVF).

The New Zealand Multiple Birth Association (NZMBA) – 0800 489 467

Provides support, clubs, information and advice via newsletters and resource material.