[AllegraM]

Spoilsport scientists!

http://www.abc.net.au/science/articles/201.../22/3638581.htm


"There is a widespread belief that sex during the later stages of pregnancy can jumpstart labour, but that doesn't appear to be so - at least according to a study from Malaysia.

The researchers, whose work appeared in BJOG: An International Journal of Obstetrics and Gynaecology, found that there were no differences in the timing of delivery between women who had sex near term and those who abstained.

"We are a little disappointed," says Tan Peng Chiong, an obstetrics and gynecology professor at the University of Malaya and one of the authors of the study.

"It would have been nice for couples to have something safe, effective and perhaps even fun that they could use themselves to help go into labour a little earlier if (they) wanted."

Tan says that many women believe intercourse can induce labour, and scientists have proposed plausible biological explanations for why it might help.

For one, semen contains a hormone-like substance called prostaglandin, which is used in synthetic form to induce labour. Breast stimulation is also thought to hasten labour and orgasm can trigger uterine contractions.

"Labour induction for prolonged pregnancy is common and many women are also tempted for a variety of personal reasons to trigger labour in the very later stages of pregnancy," says Tan.

Randomised trial

The researchers invited more than 1100 women to participate, all of whom were 35 to 38 weeks pregnant and none of whom had had sex in the previous six weeks.

Roughly half of the women were advised by a physician to have sex frequently as a means of safely expediting labour. The other half were told that sex was safe during pregnancy, but that its effects on labour were unknown.

The researchers then tracked the women to determine how long their pregnancies lasted and whether they required any medical intervention to start labour.

They found that about 85 per cent of the women who were encouraged to have sex did follow the doctor's advice, while 80 per cent of women in the other group also had sex.

Women in the group advised to have sex also had it more frequently for the remaining duration of their pregnancies - three times versus two.

But the rates of induced labour were similar in both groups: 22 per cent of those advised to have sex and 20.8 per cent of the other group, a difference so small it is likely to have been driven by chance.

Pregnancy 'robust to the end'

Earlier research relied primarily on surveys of women about their sexual experiences during pregnancy, but this study was "the first attempt to really randomise the experience, for some to have sex and some to not, which is a very hard thing to do," says Dr Jonathan Schaffir, an associate professor of obstetrics and gynaecology at the Ohio State University College of Medicine.

"Even though this study did not show any increase in the rate of labour or a decrease in the rate of induction, it helped to cement the idea that having sex is probably safe if you want it," he says.

Tan says the results show that pregnancy evolved to be resistant to disruption.

"Human pregnancy has to be robust to a little adventure like intercourse and unfortunately for our purpose, it seems pretty robust to the very end," he says."

This post has been edited by AllegraM: 23/11/2012, 06:45 AM

[HeroOfCanton]

Hmm, study says no, but that doesn't mean people can't keep trying

[girltribe4]

I wasn't trying to bring labour on as I was only 37wks but DD#2 's birth started a few hours after we DTD , She was my only early baby .

[diegov]

Not a very well controlled study when both groups having sex.... Lol
It's the prostaglandin in semen that induce labour. More to the point, prostaglandins ripen the cervix for labour.

[InsertAwesomeHer...]

Not a very well controlled study when both groups having sex.... Lol
It's the prostaglandin in semen that induce labour. More to the point, prostaglandins ripen the cervix for labour.

I knew this already but just curious. If you are already dilating slowly (due to previous pregnancies) and slightly thinned out is it really going to make a difference?

[Bluenomi]

Thank goodness! The last thing I wanted to do at 40 weeks was the deed.

[maneki_neko]

May as well make the most of it though, chances are you won't be up to it for at least a few weeks afterwards!

[soontobegran]

Hmm?
Not sure about the trial but having sex will not bring on labour unless you are 'ready' anyway but I most definitely think that depositing a heap of prostaglandins onto the cervix does get things going in many women.
The number of women who have come in post sex in labour would make it seem to be a bit of a coincidence if it does nothing......no harm in trying

[CallMeProtart]

A bit odd that it was the 'rates of induced labour' they used as their measure of success?

I mean I get that it would be faults in any measure, but wouldn't average gestation at occurrence of natural labour be the better measure?
I'd have thought that the women who had to be induced were probably not going to go into labour by any subtle or natural means anyway - it'd be the ones who were on the brink of natural labour that would go earlier due to the prostoglandins...

What their experiment is effectively measuring is "Is sex as effective an inducer of labour as syntocin?" which is a much bigger claim...
Assuming the reporting of the study is correct.

ETA. HangonWHUT? Did I read it correctly? Both groups had sex at roughly the same rate anyway (80-85%).... but they still figured it was valid to compare both groups induction rates and draw a conclusion? Um.... scientific method FAIL!

This post has been edited by CallMeAliG: 23/11/2012, 01:42 PM

[diegov]

I knew this already but just curious. If you are already dilating slowly (due to previous pregnancies) and slightly thinned out is it really going to make a difference?

Yes will make a difference! Helps dilation speed up/ happen easier