Your three stages of pregnancy

three stages of pregnancy
Pregnancy is full of confusing medical jargon - but think of "trimesters" as just a handy way of dividing up your 40 weeks into stages or chunks of time.

The first trimester is 0 to 13 weeks, the second 14 to 26 weeks and the third 27 to 40. Obviously though not all pregnancies reach full term as babies are born prematurely and equally some are overdue.

Your first trimester

This starts from the first day of your last period, so by the time your period is late you are already technically 4/5 weeks pregnant - even though your baby is just 2mm long at this point.

  • What's happening to me now?
    You may not have noticed your period is late at week 4/5, but some women begin to notice changes in their body in the next few weeks. These can include breast tenderness, changes in your sense of smell and taste, (many women report a metallic taste in their mouth or go off tea or coffee). 

    You may also start to feel nausea as pregnancy hormones begin to flood your body. A pregnancy test will be able to confirm your pregnancy. Your GP or midwife should advise you to take folic acid during this time to prevent spina bifida, a neural tube defect.

  • What about my baby?
    By week seven the embryo will be 10mm long and the brain will be growing rapidly and small limb buds are visible. The heart can sometimes be seen beating on an internal vaginal ultrasound scan too.

    By week 10 the baby will be fully formed with almost all its internal organs formed and measure 85mm long.

  • What about baby scans?
    By around week 10 you'll usually have seen your GP or midwife to book in for care.

    Around now (between weeks 9 to 14), you'll be offered the chance to have a booking or dating scan to check your baby is the right size for your dates and give you an Estimated Delivery Date. As part of this scan you'll be usually offered a nuchal translucency scan, which measures fluid at the back of the baby's neck, as a part of a combined screening test for Down's syndrome.

    In some hospitals very early internal scans using trans vaginal equipment may be offered for special reasons such as threatened miscarriage.

Your second trimester

This is when you'll be telling most people - such as work colleagues and family that you're pregnant, as once you've entered the second trimester the risk of miscarriage recedes.

  • What's happening to me now? 
    In the second trimester you'll start to look visibly pregnant and develop a "bump" and need maternity clothes. Some women (but not all) experience a pregnancy " bloom" around this time with thicker, glossier hair and find they have more energy than earlier on.

    Your nausea should start to subside in most cases and around month five you should feel your baby move for the first time and definite kicks a few weeks later. 

  • What about my baby?
    Your baby will be hiccupping, swallowing and kicking by around week 16 . By week 18 they'll begin to look more human and even their fingernails and toenails are well developed. By 24 weeks they have a chance of surviving if more prematurely. 
  • What about baby scans?
    Between 19 and 24 weeks you'll be offered an anomaly scan, which checks for abnormalities in your baby. It can also tell you the sex of your baby. This is not compulsory though and your choice. If the scan does detect a problem though you'll be given expert counselling on what this means for your baby.

Your third trimester

Your bump gets big and the realisation that you're really going to become a mum finally sinks in. Yes it's real and it's going to happen.

  • What's happening to me now?
    Your body is starting to prepare for labour; your baby is moving down into your pelvis and you'll need to pass urine more frequently. You may experience Braxton Hicks contractions - where your uterus contracts (painlessly) in preparation for labour. You may feel you have less energy in the final weeks.

  • What about my baby?
    Your baby is gaining weight and their lungs are maturing; as the next weeks progress there will be less room for them to move around.

  • What about baby scans?
    You may have extra scans in the third trimester if there are concerns about your baby's growth, low lying placenta (where the placenta partially blocks the opening to the vagina) or any other complications.

  • Ultrasound Direct offers specialist private antenatal ultrasound scans at a time and place to suit you with clinics all over the UK . For a full list of scans including 3D and 4D scans click here