Pregnancy & Birth

A new NZ study on pregnancy has revealed what time of day babies are most likely to kick

How often babies kick varies widely, but the time of day they're most active was consistent across the board.

A new study led by researchers at Auckland University has shed light on what’s ‘normal’ in terms of when you should feel your baby ‘kick’ during pregnancy – and it really is a case of ‘when things go bump in the night’.

The study has found that in late pregnancy babies are more active in the evening and bedtime, and babies’ movements tend to keep getting stronger even as they near term.

The study of pregnant women’s own observations, published in scientific journal PLOS One, debunks some myths about babies’ movements during pregnancy and gives much-needed, clear guidance to women and their health professionals about what is normal.

“Pregnant women are often advised to keep an eye on their baby’s movement pattern and report any decrease in movements,” says lead author, Billie Bradford, a PhD student in the University’s Faculty of Medical and Health Sciences and a practicing midwife.

“But, even though there is a link between decreased movements and stillbirth, most women who report a drop in activity will go on to have a healthy baby. The problem is, there is limited evidence about what normal patterns of movement look like, and around the world women are getting mixed advice. We thought this would be useful information, particularly for first-time mothers who are getting to know what a normal pattern is for them.”

The research team interviewed pregnant women from across New Zealand who were in their third trimester (after 28 weeks of pregnancy) about the nature and frequency of their babies’ movements.

The main findings were:

• Almost two thirds (59 per cent) of women reported feeling movements getting stronger in the previous two weeks (to birth)

• Strong movements were felt by most women in the evening (73 per cent) and at night-time including bedtime (79 per cent)

• Women were more likely to perceive moderate or strong movements when sitting quietly compared with other activities

• Almost all women reported feeling their babies hiccup

“Probably the most surprising finding was just how profound an influence time of day was – only 3.7 percent of women did not feel strong or moderate movements in the evening,” says Bradford.

Pregnant women have always reported more baby movements in the evening but up until now this has been put down to the mother being too distracted or busy during the day to notice when her baby moves.

But Bradford says that may not be the case.

“A number of ultrasound and animal studies have shown that the fetus has a circadian pattern that involves increased movement in the evening, and this is likely to reflect normal development.”

Interestingly, newborn babies are very active in the evening and sometimes at night. Known as the ‘witching hour’ every parent of a newborn will have experienced this.

The study showed that the number of kicks pregnant women reported feeling varied widely, from four to 100 an hour – so counting kicks is a less accurate measure of how your unborn baby is doing.

The take-home message for pregnant women: if your baby usually gets busy at night, rest (if you can) assured. If you’re concerned that your baby is moving less often, less strongly or not moving in the evening as they normally would, don’t wait until the next day for a check-up.

“It may be an antisocial hour for adults, but it is a social hour for the fetus (and incidentally the newborn), so lack of movement at that time warrants an urgent check-up,” says Bradford.

The study’s other authors were from the University of Auckland and the Liggins Institute.

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