Total days of pregnancy lost per 1000 births
The total number of days of pregnancy lost per 1000 births in a group is a sensitive measure of preterm birth.
The number of days of pregnancy lost because of preterm birth increased significantly from 2021 to 2022 in San Francisco.
Data notes and sources
Data notes and sources
The days of pregnancy lost variable sums up the total days of pregnancy lost for each member of a population group. If one person is meant to have 40 weeks of pregnancy, it calculates how many days short they are and sums it up for the population group.
It detects small changes in preterm birth risk over time. It detects preterm birth risk for small groups with as few as 10 total births. A large number of days of pregnancy lost means that a few babies in the group were born many weeks early AND/OR many babies in the group were born only a week early.
The measure provides early warning of need for services.
Data source:
- California Department of Public Health (CDPH) Vital Record Business Information System (VRBIS). VRBIS data include one birth certificate record for each and every baby born in California.
- Data were analyzed by the San Francisco (SF) Department of Public Health Maternal Child & Adolescent Health Epidemiology Section.
Data notes:
- Preterm birth is defined as live birth before 37 weeks of pregnancy. Very preterm birth is live birth before 32 weeks of pregnancy.
- We count preterm births experienced by San Francisco residents between January 1 and December 31 of each year.
Data limitations:
- Data are not shown if the number of preterm births in the group is less than 20 to protect the privacy of individual people in the group.
- The total numbers shown here may undercount the true numbers, because we do not count preterm births that happened outside of California, in other states or countries.
- We do not count babies delivered in San Francisco by people who are not San Francisco residents.
Two rates are significantly different if their 95% confidence intervals do not overlap. The 2022 rate is significantly different form the rate for 2021. The 2022 rate is also significantly higher than the rate ten years ago in 2013.
Days of pregnancy lost because of preterm birth by population group
Last year, the risk of preterm birth increased significantly for population groups with the following risk factors:
- Under age 25
- Black or African American
- Missing or unknown prenatal care
- Eligible for WIC but not receiving WIC services
- Gonorrhea
- Address is a Single Resident Occupancy Hotel (SRO)
- Birth at UCSF
Data notes and sources
Data notes and sources
Data source:
-
California Department of Public Health (CDPH) Vital Record Business Information System (VRBIS). VRBIS data include one birth certificate record for each and every baby born in California.
-
Data were analyzed by the San Francisco (SF) Department of Public Health Maternal Child & Adolescent Health Epidemiology Section.
Data notes:
-
Abbreviations: CPMC: California Pacific Medical Center; UCSF: University of California San Francisco; ZSFG: Zuckerberg San Francisco General.
-
Race and ethnicity were self-reported by the parent(s) and grouped by the California Department of Public Health, which separates multi-race Hispanic and single race Hispanic groups.
-
Quality of prenatal care was checked using the Kotelchuck index
-
The birth record notes if the birthing parent was ever diagnosed by a doctor with high blood pressure before or during pregnancy and if they were ever diagnosed with diabetes before or during pregnancy.
Data limitations:
-
Data are not shown if the number of preterm births in the group is less than 20 to protect the privacy of individual people in the group.
-
The numbers shown here may undercount the true number of preterm births because we did not count preterm births delivered by San Francisco residents outside of California, in other states or countries. The birth record data may be incomplete because of health conditions that were not diagnosed.
-
We do not count babies delivered in San Francisco by people who are not San Francisco residents.
Days of pregnancy lost because of preterm birth by zip code
The number of days of pregnancy lost because of preterm birth increased significantly in several zip codes in San Francisco.
The worst increase was in the Treasure Island zip code (94130).
Data notes and sources
Data notes and sources
Data source:
-
California Department of Public Health (CDPH) Vital Record Business Information System (VRBIS). VRBIS data include one birth certificate record for each and every baby born in California.
-
Data were analyzed by the San Francisco (SF) Department of Public Health Maternal Child & Adolescent Health Epidemiology Section.
Data notes:
-
Abbreviations: CPMC: California Pacific Medical Center; UCSF: University of California San Francisco; ZSFG: Zuckerberg San Francisco General.
-
Race and ethnicity were self-reported by the parent(s) and grouped by the California Department of Public Health, which separates multi-race Hispanic and single race Hispanic groups.
-
Quality of prenatal care was checked using the Kotelchuck index
-
The birth record notes if the birthing parent was ever diagnosed by a doctor with high blood pressure before or during pregnancy and if they were ever diagnosed with diabetes before or during pregnancy.
Data limitations:
- Data are not shown if the number of preterm births in the group is less than 20 to protect the privacy of individual people in the group.
- The numbers shown here may undercount the true number of preterm births because we did not count preterm births delivered by San Francisco residents outside of California, in other states or countries. The birth record data may be incomplete because of health conditions that were not diagnosed.
- We do not count babies delivered in San Francisco by people who are not San Francisco residents.
More information
See linked pages about preterm birth in San Francisco