1. Health

Lifestyle Factors That Increase Risk of Miscarriage and Stillbirth

Overview of Known Risk Factors That Increase Risk of Pregnancy Loss


Updated June 04, 2014

Rarely is pregnancy loss anyone's fault; random chromosomal abnormalities cause the vast majority of miscarriages. Even women with the healthiest lifestyles can and do have miscarriages. Some lifestyle factors, however, do appear to increase risk of miscarriage and stillbirth. The exact link is not always understood. Usually, no one can tell whether any particular factor caused a specific pregnancy loss, but avoiding known risk factors is one small way to reduce risk of pregnancy loss.

Smoking and Secondhand Smoke

The link between smoking and miscarriages is controversial and not yet well understood, but numerous studies have found statistical links between exposure to cigarette smoke and risk of pregnancy loss. Avoiding cigarette smoke is probably one of the biggest ways that women can reduce miscarriage and stillbirth risk (although, again, nothing will eliminate risk entirely, and even women with no miscarriage risk factors can have pregnancy losses).


Occasional, light drinking before conception probably does not affect risk of miscarriage, and recent research has found that having drunk heavily once or twice before finding out about a pregnancy is not likely to cause miscarriage.

However, regular intake of even moderate amounts of alcohol – especially while pregnant – is correlated with a higher risk of miscarriage.

Substance Abuse

Beside alcohol, using other drugs can be associated with increased risk of both miscarriage and of stillbirth. Marijuana may reduce oxygen supply to the baby, increasing risk of low birthweight, preterm delivery, and stillbirth. Cocaine increases miscarriage risk and risk of placental abruption, as does use of methamphetamines.


There is some data that suggests that maternal obesity can increase risk. Women should work to maintain a healthy weight before conception.

Certain Prescription Medications

Although they are used for legitimate health concerns, several prescription drugs are associated with increased risk of miscarriage and stillbirth. One common example is ACE inhibitors, a type of blood pressure medication. Drugs with FDA pregnancy safety rankings in Category D or Category X may be associated with pregnancy loss risk.


The link between caffeine and miscarriage is controversial; some studies have found a link with moderate to heavy caffeine intake. Other studies dispute this link, and some theorize the link between caffeine and miscarriage might instead by explained by a tendency toward more coffee intake by women already destined to miscarry (they tend to experience less nausea and morning sickness.)

Until researchers better understand the connection between caffeine and miscarriage, it seems prudent to avoid heavy exposure to caffeine while pregnant just to be on the safe side.

Untreated Chronic Health Conditions

With adequate prenatal care, women with chronic health conditions have excellent chances to have a normal pregnancy. But some health conditions, such as diabetes and systemic lupus erythematosus, may mean increased miscarriage or stillbirth risk if a woman conceives when the conditions are not under control.

Eating Unpasteurized Raw Foods While Pregnant

Listeria and a few other foodborne bacterial infections can cause miscarriage. It is good practice for women to avoid unpasteurized, raw cheese and deli meats during pregnancy.

Occupational Chemical Exposures

Certain chemicals, such as pesticides and other petrochemicals, are known to increase risk of miscarriage. Women working around chemicals, and women whose partners work around chemicals, may have increased pregnancy loss risks.


American Pregnancy Association, “Using Illegal Drugs During Pregnancy.” May 2007. Accessed 31 Dec 2007.

American Pregnancy Association, "What's the Real Scoop on Caffeine During Pregnancy." Aug 2007. Accessed 31 Dec 2007.

Figa-Talamanca, Irene. "Occupational risk factors and reproductive health of women." Occupational Medicine 2006. Accessed 31 Dec 2007.

Rasch, V, "Cigarette, alcohol, and caffeine consumption: risk factors for spontaneous abortion." Acta Obstetrics and Gynecology Scandinavia Feb 2003. Accessed 31 Dec 2007.

Related Video
How to Reduce the Risk of SIDS
Understanding Baby Eczema

©2014 About.com. All rights reserved.

We comply with the HONcode standard
for trustworthy health
information: verify here.