Drinking alcohol while pregnant increases the chances of a miscarriage by up to 40 per cent, according to a new study.
It doesn’t matter how much or what kind of booze, drinking alcohol during the first five to ten weeks of pregnancy increases the risk of having a miscarriage, scientists have warned.
While most lay off the drink after finding out they are pregnant, it is not uncommon for women to consume alcohol before realising they have a baby on the way, whether planned or not.
Author Dr Katherine Hartmann at the Vanderbilt University Medical Center (VUMC) in the United States said: “Abstaining from alcohol around conception or during pregnancy has long been advised for many reasons, including preventing foetal alcohol syndrome.
“Nonetheless, modest levels of consumption are often seen as likely to be safe.”
How booze harms early pregnancy is not known, although scientists suspect it interferes with womens’ hormone levels, increasing oxidative stress, impairing key pathways and reducing the quality of implantation.
On average, one in six pregnancies ends in a miscarriage, which can cause emotional trauma and unanswered questions, according to the scientists.
Dr Hartmann said: “For this reason, our findings are alarming.
“Levels of use that women, and some care providers, may believe are responsible are harmful, and no amount can be suggested as safe regarding pregnancy loss.”
Getting the timings right is crucial considering women are most likely to consume alcohol in the first few weeks, when the embryo develops most rapidly and lays down the “pattern for organ development”.
Over 5,000 women planning or in early pregnancy from eight metropolitan areas in Tennessee, North Carolina and Texas, were interviewed about their alcohol consumption during their first trimester – a three month window.
Around half the women reported drinking alcohol around conception and during the first weeks of pregnancy.
The risk of having a miscarriage was almost 40 per cent higher compared to women who did not drink, the researchers found.
This was even among women who stopped drinking within three days of a positive pregnancy test or after missing their period.
Co-author Dr Alex Sundermann, who recently graduated from VUMC, said: “Combining the facts that the cohort is large, comes from diverse communities, captures data early in pregnancy and applies more advanced analytic techniques than prior studies, we’re confident we’ve raised important concerns.”
What kind of alcohol was consumed, how much and when, did not change the level of risk, the researchers also found.
The research affirms the importance of using home tests, which can detect pregnancy before a missed period, as well as advising women to stop drinking when planning to have a baby or when it is a possibility.
The findings were published in the American Journal of Obstetrics and Gynaecology.