Women who drink moderately do not face a longer wait to become pregnant

November 28, 2001

Women who regularly drink a moderate amount of alcohol while trying to conceive do not have to wait longer than teetotallers to become pregnant, according to new research published today (Thursday 29 November) in Europe's leading reproductive medicine journal, Human Reproduction*.

In fact, the study shows that women who do not drink at all can actually take longer to become pregnant than those women who consume an average of between a half and 14 alcoholic drinks a week.

The study of nearly 40,000 women in Denmark is large enough to offer reassuring evidence which contradicts the findings of previous, smaller studies suggesting that even low levels of alcohol intake are associated with longer waiting times to pregnancy. In women who had never given birth before, neither moderate nor high alcohol intake was related to a longer waiting time to pregnancy.

However Mette Juhl, the Danish researcher who headed the study, sounded a cautionary note: "Our research does not mean that consuming alcohol is better for fertility than not drinking alcohol at all. It is known from other studies that non-drinkers differ from moderate drinkers in many other aspects; for instance they may have a weaker constitution or other health problems which can influence fertility, directly or indirectly," she said.

Ms Juhl and her colleagues, from centres in Copenhagen and Aarhus, did find that women who had given birth before and who consumed more than the Danish recommended maximum weekly intake of 14 alcoholic drinks did have to wait longer to get pregnant. However, the evidence from the study was not strong for this as there were few women in this group. Older women and women who smoked or who were over-weight also had to wait longer to become pregnant. Non-drinking, over-weight women had to wait the longest of all. These findings support the evidence of previous studies.

The study was carried out within the Danish National Birth Cohort, a nationwide study of pregnant women and their babies. The researchers asked 39,612 women between 1997 and 2000 how much alcohol they had drunk weekly on average prior to conception and how long it had taken them to become pregnant. Low levels of drinking were measured as being between a half and two drinks a week, moderate drinking was between two and a half and 14 drinks a week, and high was measured as over 14 drinks a week.

Out of the 39,612 pregnancies, 29,844 were planned and did not have complicating factors such as endometriosis, ovarian or cervical cancer. Of these 29,844 women, roughly half became pregnant within two months of trying, but 15% had to wait more than a year. Most women (79%) reported an alcohol intake of between a half and seven drinks a week, 12% reported no intake at all and one per cent reported a high intake.

Of the women with a high alcohol intake, 22% had to wait more than a year to become pregnant, while only 14% in the low-drinking group had to wait that long. In the group of women who drank no alcohol 18% had to wait more than a year.

The researchers adjusted their results to take account of confounding factors such as pelvic disease, a history of fertility treatment, partly-planned pregnancies, age, smoking, the women's weight and whether they had given birth before or not.

Ms Juhl said: "Recent studies on alcohol and fertility suggest that even low levels of alcohol intake are associated with longer waiting times to pregnancy. Our very large study does not show the same association, even for women who consume up to 14 drinks a week. The slightly higher waiting times for women who consumed more than that disappeared after we took account of whether they had given birth before or not. However the results of our study do not provide arguments against the Danish recommended intake of less than 14 drinks a week for women.

"The most consistent finding was a longer waiting time to pregnancy in women who reported no alcohol intake. We do not expect alcohol to improve a woman's fertility, but a moderate intake may correlate with a higher frequency of intercourse, which may explain the longer waiting times in women who reported no intake. Small amounts of alcohol may have a positive impact on the female reproductive system, perhaps by helping women to feel more relaxed.

"However it is important to underline that we only had information on average weekly intake of alcohol before pregnancy. Our results cannot rule out that alcohol intake on specific occasions around the time of ovulation may reduce the chance of becoming pregnant in that menstrual cycle."
* Moderate alcohol consumption and waiting time to pregnancy. Human Reproduction. Vol 16. No 12. pp 2705-2709.

1. PDF version of this press release and full embargoed text of the paper with complete results and participating research teams can be found from 09.00 GMT Tuesday 27 November on website: http://www3.oup.co.uk/eshre/press-release/dec01.pdf

2. Human Reproduction is a monthly journal of the European Society of Human Reproduction and Embryology (ESHRE). Please acknowledge Human Reproduction as a source. ESHRE's website is: http://www.eshre.com

3. Printed texts available on request from Dr Helen Beard, Managing Editor. Tel: +44 (0) 1954 212404 or email: beard@humanreproduction.co.uk

Emma Mason (media relations officer) Tel: +44 (0) 1376 563090. Fax: +44 (0) 1376 563272. Mobile: +44 (0) 7711 296986. Email: wordmason@aol.com

European Society of Human Reproduction and Embryology

Related Fertility Articles from Brightsurf:

What are your chances of having a second IVF baby after fertility treatment for the first?
As the restrictions on fertility clinics start to be lifted and IVF treatment resumes, research published in Human Reproduction journal offers reassuring news to women who have had to delay their treatment for a second IVF baby because of the coronavirus.

Fertility preservation use among transgender adolescents
Transgender adolescents often seek hormonal intervention to achieve a body consistent with their gender identity and those interventions affect reproductive function.

A new way to assess male fertility
Current tests for male fertility include measuring the concentration and motility of spermatozoa.

Male fertility after chemotherapy: New questions raised
Professor Delb├Ęs, who specializes in reproductive toxicology, conducted a pilot study in collaboration with oncologists and fertility specialists from the McGill University Health Centre (MUHC) on a cohort of 13 patients, all survivors of pediatric leukemia and lymphoma.

Vaping may harm fertility in young women
E-cigarette usage may impair fertility and pregnancy outcomes, according to a mouse study published in the Journal of the Endocrine Society.

Are fertility apps useful?
Researchers at EPFL and Stanford have carried out an analysis of the largest datasets from fertility awareness apps.

Marijuana and fertility: Five things to know
For patients who smoke marijuana and their physicians, 'Five things to know about ... marijuana and fertility' provides useful information for people who may want to conceive.

How could a changing climate affect human fertility?
Human adaptation to climate change may include changes in fertility, according to a new study by an international group of researchers.

Migrants face a trade-off between status and fertility
Researchers from the universities of Helsinki, Turku and Missouri as well as the Family Federation of Finland present the first results from a new, extraordinarily comprehensive population-wide dataset that details the lives of over 160,000 World War II evacuees in terms of integration.

Phthalates may impair fertility in female mice
A phthalate found in many plastic and personal care products may decrease fertility in female mice, a new study found.

Read More: Fertility News and Fertility Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.