Counting contractions: the interval that matters

Your belly goes hard, stays that way for a while, then softens again. Was that a contraction? And if so, which kind? In the last few weeks the question comes up every single day, and the answer decides whether you go back to sleep, pack your bag or get in the car. Here's what tells the different types of contractions apart, how to time them, and when to call.

Three types of contractions

The uterus is a muscle, and it starts practising long before the birth. That feels different at different stages.

Practice contractions (Braxton Hicks) can turn up from the middle of pregnancy onwards. Some women feel them from week 20, many not until week 30. Your belly goes hard for twenty to sixty seconds, then relaxes again. They're irregular, stay mild, don't hurt, and they disappear when you change position, drink a glass of water or take a warm bath. They often come in the evening, after exertion, or when your bladder is full.

Lightening contractions come in the last three to four weeks. They push your baby deeper into your pelvis. You feel them as a downward pulling, similar to period pain, and sometimes in your back too. Afterwards breathing is easier, because there's less pressure on your diaphragm, and trips to the toilet get more frequent, because there's more pressure on your bladder. These are irregular as well, and they don't get stronger.

Labour contractions are different, in three ways: they come regularly, they get stronger, and they don't stop, no matter what you do. At first perhaps every fifteen or twenty minutes, then every ten, then every five. Each one lasts longer than the one before, and the pain often travels from your back to the front or the other way round. During a real contraction you can no longer chat alongside it.

The difference isn't in the strength of a single contraction, it's in the pattern over an hour. That's why you count.

What you're measuring

Two numbers and one observation.

The duration is the time from the start to the end of one contraction: from the moment your belly goes hard until it's soft again. Practice contractions usually last under a minute. Labour contractions start out at thirty to forty seconds and get longer over the hours, until they last a minute or more.

The interval is the time from the start of one contraction to the start of the next. Not from the end to the next start. That's the most common mistake when timing at home, and it makes a real difference: with a duration of one minute and a four minute break, the interval is five minutes, not four. In the delivery room it's counted from start to start, so count it the same way at home.

Regularity is the observation: does the interval stay roughly the same over an hour, or does it get shorter? Practice contractions come after eight minutes, then twenty, then three. Labour contractions keep their rhythm.

The rule hospitals ask about

Most hospitals and midwives give a similar rule of thumb: call when contractions are coming about every five minutes, each one lasts about a minute, and it's been going like that for an hour.

The rule has exceptions, and you should talk them through with your midwife in advance:

• With a second or third baby it's often faster. Many hospitals will then say: set off when contractions are seven to ten minutes apart.
• If you have a long journey to the hospital, set off earlier too.
• For a planned home birth or birth centre birth, what you've agreed with your midwife applies, not the rule.
• If you've had a caesarean before, or there are other special circumstances, the hospital may specifically ask you to come in earlier.

And the rule is about the numbers. There are reasons to leave straight away, whatever the clock says.

Go now, whatever the clock says

• Your waters have broken, even without contractions. Especially if the fluid is greenish or brownish.
• Bleeding that's more than the slightly bloody mucus you see when the mucus plug comes away.
• Contractions before 37 completed weeks.
• You feel your baby moving noticeably less than usual.
• Severe, constant pain that doesn't come and go in waves like contractions.
• Severe headache, vision changes, sudden swelling in your face.
• Something just doesn't feel right to you. That's reason enough.

When in doubt, calling is always the right move. The people in the delivery room will listen, ask questions, and tell you whether to come in. That's what they're there for, at three in the morning too.

Counting without the stress

Not every tightening of your belly needs to be timed. If a few practice contractions turn up in the evening, watch them, change position, have something to drink. If they disappear, that was it.

Start timing when the contractions start to feel regular or get stronger. Then you need an hour's worth of times. Paper works fine: start, end, start, end. More practical is something that does the maths for you, because you don't want to be subtracting numbers mid contraction. Lunabia has a contraction timer for this: tap when one starts, tap when it ends, and the app works out the interval from start to start and the duration, shows you the last hour, and tells you when the rule is met. And the person handling the phone can be your partner, while you look after the contraction.

Between contractions: move around if you can, drink, eat something small, go to the toilet. An empty bladder gives contractions room. And if it all starts at night and the intervals are still long, try to sleep. The contractions will wake you when it's time.