What to expect & what to do for each stage of pregnancy

Dr Nick Walker outlines what to expect in each trimester and offers a handy to-do list to help you on your way.

1st Trimester

FROM CONCEPTION TO AROUND 14 WEEKS

Two weeks after your last menstrual cycle, ovulation then conception occurs, and a tiny group of cells that will become your baby settles into your uterus. As those cells then begin to multiply, they attach and begin to draw nutrients from the heightened blood supply forming there. These new cells create a special hormone known as HCG, which, when released into the mother’s blood stream, causes both the symptoms of pregnancy and the triggering of the ‘positive’ indicator on a home pregnancy test: you’re pregnant!

If this is your first pregnancy, this confirmation will be especially exciting, and perhaps a bit nerve-wracking as you then consider what to do next!

The HCG hormone can also be measured by a blood test, which is more precise than a domestic urine test. A blood test is usually only necessary on the advice of your doctor; many women gain no extra benefit from blood testing during early pregnancy.

THE FIRST SCAN

The very best next step in confirming your pregnancy is to arrange for an early ultrasound scan, a good time being between seven and ten weeks gestation. The scan is low-tech, zero harm, and much fun: you’ll easily see a tiny body and hear a rapid heart beat (or even two of each as the scan may reveal twins!).

CHOOSING AN LMC

Around the same time as your scan, start considering who will look after your pregnancy, professionally speaking. In New Zealand you can choose an 'LMC' (Lead Maternity Carer) who guides you through the next nine months.  LMCs are predominantly midwives (independent or hospital-based), though a small proportion are doctors (GPs or obstetricians) depending on local availability. Choosing an LMC can be difficult so if in doubt, ask friends and family or contact your local family medical centre or District Health Board. 

HEALTH SCREENING

Your LMC will arrange another round of scans and blood tests – all part of routine ‘screening’ for the health of you and your baby. Testing for detectable genetic disorders has evolved a lot in the last five years, and your LMC can guide you through these processes and manage your results. They will also be on hand to help with common problems like nausea and fatigue, and to address any questions or concerning symptoms.

IMPORTANT DIETARY SUPPLEMENTS: FOLATE 

There is a range of dietary supplements on offer for those planning pregnancy and waiting to conceive, but the most important micronutrient contained in these is folic acid, or folate. Folic acid has a direct action in reducing the likelihood of a birth defect known as spina bifida. Many women become pregnant without planning beforehand, and may miss the ideal window of folic acid supplementation, therefore ideally you should be taking a folate supplement just prior to conception, and aim to continue using it until at least 12 weeks of pregnancy.

IODINE SUPPLEMENTS

Several years ago, the New Zealand Ministry of Health recommended universal supplementation of the mineral iodine during pregnancy and lactation. This recognises the facts that our soils and therefore food sources are low in iodine, and that fewer people these days are regularly using iodised salt. Your iodine requirements increase during pregnancy and breastfeeding, and the consequences of iodine deficiency can be severe. The supplement is recommended from the first trimester onwards. Any excess iodine you take in is easily cleared through your urine, so it does not matter if you already use iodised salt.

PROBIOTIC SUPPLEMENTS

Another common type of ‘supplement’ is a probiotic capsule. These contain colonies of various types of bacteria thought to be beneficial to health.  In a 2017 study into their use during pregnancy, a surprise outcome was the finding that their use was associated with a lower risk of post-natal depression. Further research should provide more insight into this interesting matter: watch this space!

YOUR DIET

A well-balanced diet will provide all the necessary ingredients for a healthy pregnancy and baby. As long as you were nutritionally sound going into the pregnancy there's no cause for concern about your dietary needs at this stage. Babies efficiently take what they need directly from their mother’s bloodstream, and do not yet need too many calories.

First trimester recap:

✔ Get a dating scan 7-10 weeks after your last menstrual period.

✔ Book your care with an LMC, who will then arrange pregnancy specific tests from 11-14 weeks.

✔ Survive any nausea/vomiting. 

2nd Trimester

14 – 28 WEEKS

The most important step in your second trimester is for your LMC to help arrange another ultrasound scan, often called the '20-week scan', the 'anatomy scan' and the 'morphology scan'. This scan is a comprehensive assessment of baby’s physical wellbeing, and will also assess placental location and position. 

EXERCISING AND RELAXING

Most women find the troublesome earlier symptoms have resolved and look to get back into general exercise, which is beneficial and recommended during pregnancy for physical and mental wellbeing. Remember, though, that pregnancy will limit your ability to exercise to your usual standard; it’s easier to become tired and out of breath even from the early stages of pregnancy.  Steady walking and light jogging are acceptable, while yoga- and Pilates- type exercises are very popular and also completely safe. Many instructors even offer pregnancy-specific classes to cater for the demand from women who wish to remain strong and flexible in preparation for labour and birth.

The opposite of exercise is relaxation, and you should definitely put aside time for this. The ultimate form of relaxation is of course sleep, which is as important now as at any other time in your life.  Unfortunately, sleep disturbance is really common during each trimester due to a range of issues, such as nausea (first trimester), frequent visits to the toilet to empty the bladder (second trimester), foetal activity (third trimester) and musculoskeletal discomfort (any trimester!).

AVOID HARMFUL SUBSTANCES

No article on staying healthy during pregnancy would be complete without a reminder to avoid tobacco, alcohol and drugs. Smoking produces carbon monoxide in your blood, lowering the oxygen levels available to your baby.  During pregnancy, the developing baby is thought to be particularly sensitive to alcohol exposure, as evidenced by the most extreme example – foetal alcohol syndrome.  There is no known safe limit for alcohol in pregnancy, so an absolute tee-total approach is the only recommendable option.  

DIABETES AND IRON TESTING 

Between 24 and 28 weeks your LMC will arrange a second round of lab tests, to assess for various issues such as anaemia and low iron, pregnancy-induced diabetes and urinary tract infections. The diabetes testing involves a deliberate challenge of your metabolism with a liquid glucose drink, which can be a daunting task even for those claiming to have a ‘sweet tooth’. Once these results are collated and managed, the second trimester is over!

Second trimester recap:

✔ 20-week scan, the most important scan of any pregnancy.

✔ Repeat blood and urine tests, including diabetes glucose challenge.

✔ Enjoy the general ‘normal’ feeling between the relatively more difficult first and third trimesters.

✔ See your LMC about every four weeks. 

3^rd Trimester

28 WEEKS - BIRTH

Now comes the hardest part for most women. The physical size and resultant pressure of the uterus will commonly cause breathlessness, heartburn, haemorrhoids and musculoskeletal discomfort, especially in the pelvic joints and lower spine. Your LMC can usually help advise on how to relieve these nuisances, to a degree.

In this trimester you will start having fortnightly visits to your LMC, moving to weekly visits in the month leading up to your due date. The increased frequency of visits is designed to detect (in a timely manner) the major problems encountered at this final stage: blood pressure issues, baby growth issues and baby position issues.

FINAL PREPARATIONS

Your best ways to prepare for labour and birth are to attend antenatal classes (both to meet other expectant parents and therefore experience the range of normal pregnancies), and to spend time with relatives or friends with small babies, if possible. Continuing to eat, sleep and rest well is important. It's best practice to initiate sleep on your sides as a more favourable position than your back. Your body position during sleep and upon waking is not important, only the ‘start’ position, so don’t be concerned if you wake up on your back – simply go back to your side to resume sleep. 

At some point, most LMCs will run through a so-called 'birth plan' – a bit of a misnomer as it is actually better described as a set of options, preferences, contingencies and safety checks. 'Birth plan' is simply an easier and more friendly sounding term! Key points in the birth plan are considerations such as your pain relief plan and agreed place of delivery, which of course vary widely according to the woman’s wishes and circumstances. You should receive basic information on ‘normal’ and ‘danger’ pregnancy symptoms so you have a good level of awareness and confidence about when to call your LMC.

Third trimester recap:

✔Consider antenatal classes or a refresher course.

✔ See your LMC fortnightly/weekly.

✔ Survive that final month: rest, rest and more rest.

✔ Complete a birth plan: know where to go, and when.

We could well continue through to the ‘fourth trimester’ (from birth to six weeks) but those challenges are well beyond my scope! By that stage, hopefully all hands are on deck to help with your brand new baby, now safely arrived into this world.

Dr Nick Walker is a specialist obstetrician working in public practice at National Women's Hospital and private practice in Auckland. He divides his time between these roles and helping his wife care for their four children.

Top image: @dashapats via Twenty20