This report shows the estimated count and percentage of pregnant Vermont residents who smoked any time during their pregnancy by geography and year. Smoking during pregnancy can have a negative impact on the health of women, infants, and children by increasing the risk of fertility problems and pregnancy complications. It can also increase the risk for preterm birth, low birth weight, and sudden infant death syndrome – some of the leading and most preventable causes of infant mortality. Quitting smoking prior to and any time during pregnancy carries benefits, especially considering the many additional risks of postnatal tobacco smoke exposure for infants and children. These include, but are not limited to, respiratory infections, ear infections, and asthma. 

Data used in this report are from the Vermont Department of Health (VDH) Vital Statistics System. They are for Vermont resident births, regardless of whether the birth occurred in or outside of Vermont. Vermont’s vital records (data concerning births, deaths, fetal deaths, marriages, civil unions, divorces, and dissolutions) are collected according to state and federal laws and stored in VDH’s Vital Statistics System. When a birth occurs in the state, the physician, midwife, or other birth attendant is required by law to complete a birth certificate and file it with the town clerk in the town of birth within 5 days. For hospital births, medical records staff usually complete the birth certificate. The completed birth certificate is recorded and filed in the town where the birth took place, and a certified copy is sent to VDH for incorporation in the state’s Vital Statistics System. Data are then sent to the National Vital Statistics System (NVSS), the Federal compilation of each state’s vital records data across the county, where public access is provided to statistical information from birth certificates.

Smoking during pregnancy was defined as a pregnant woman who reported smoking any time during the first (0 to 13 weeks), second (14 to 26 weeks), and/or third (27 to 40 weeks) trimester. A record was counted as a ‘smoking’ record even if it indicated a pregnant woman smoked and then quit during any one of the three trimesters.

State-level data were aggregated by year while county-level data were averaged by discrete three-year periods to account for data that may fluctuate greatly from year to year, thus maximizing reliability. Values between 1 and 10 (inclusive) were suppressed/removed for a given geography and replaced with the value ‘-999.’ Secondary suppression occurred in instances where a data element could be used to calculate a related value that was suppressed (e.g., when a numerator was suppressed for a given percentage, the denominator was also suppressed to prevent reverse calculation of the numerator). The suppression rules were enforced to prevent the identification of individuals in an effort to preserve privacy and confidentiality.

Percentages for smoking during pregancy (statewide data) were calculated using the following formula:

([Smoking Count for the Year] / [Live Birth Records with Smoking Data for the Year]) * 100

Average percentages for smoking during pregnancy (county-level data) were calculated using the following formula:

([Average Smoking Count during the Three-Year Period] / [Average Count of Live Birth Records with Smoking Data during the Three-Year Period]) * 100

Average counts and percentages used for the county-level data must be interpreted with caution due to the small sample sizes in many instances. Smoking during pregnancy is also a self-reported measure, so there may be instances of under-reporting for time periods.