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Fetal Mortality Data Technical Notes

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A fetal death is a death prior to the complete expulsion or extraction from its mother of a product of conception; the fetus shows no signs of life such as breathing or beating of the heart, pulsation of the umbilical cord, or definite movement of voluntary muscles. Fetal deaths are also referred to as stillbirths, miscarriages, or spontaneous abortions.

An infant death differs from a fetal death in that it is a death of a live-born infant within the first year of life. Infant death data are in the Infant Mortality Query.

Fetal Deaths

The fetal death certificate is the source document for the fetal death data in NJSHAD. Fetal deaths occurring after the completion of 20 or more weeks of gestation are required to be reported to the Office of Vital Statistics and Registry by New Jersey law. Induced abortions of 20 weeks or more gestation are encompassed by this requirement, but are not included in the fetal death count. Fetal death figures presented in NJSHAD, therefore, include only spontaneous fetal deaths (also called stillbirths) beyond 19 weeks of gestation. Fetal deaths of unknown or unstated gestational age are also included. Only fetal deaths occurring to females who were New Jersey residents are included.


Birth certificate data are used to calculate fetal mortality rates.

Out-of-State Fetal Deaths

Reporting of fetal deaths to New Jersey resident mothers which occurred in other states is encouraged but not required by the national Vital Statistics Cooperative Program (VSCP), which encourages the exchange of information on vital events between the states of occurrence and residence. Therefore, data files are augmented with data from CDC WONDER to obtain an accurate count of New Jersey resident fetal deaths of 20 or more weeks gestation. The fetal mortality data presented in the query system are for New Jersey residents, regardless of where the death occurred.

Data File Updates

The fetal death data in the query system were generated from data files available at the time of preparation of the back-end dataset. Any data pertaining to a fetal death for which a certificate was filed after that time or relating to corrections or revisions made since the data were processed for the electronic file are not included. Vital events computer files are periodically updated by OVSR and CHS staff based on correction reports received from local registrars and from data quality control analyses conducted by CHS. The query incorporates data from the most recently updated files.
The completeness of fetal death reporting by residence is dependent on the effective functioning of the interstate data exchange program for certificates which is fostered and encouraged by the National Center for Health Statistics (NCHS). Research has shown that by the mid-2000s, most other jurisdictions had stopped sharing fetal death records of New Jersey residents occurring in other states. Data from New York City for 2012-2017 was obtained by special request, but all that is known for other years and from other jurisdictions is the total number of missing records.

The quality of the data included in the query is a function of the accuracy and completeness of the information recorded on the respective certificates and of the quality control procedures employed in the coding and keying processes. A query program in which the individual(s) responsible for completing the certificate is questioned about missing or conflicting information is carried out by OVSR staff. This process is augmented by the data quality control analyses performed by the CHS using all of the NCHS edit criteria.
For public health planning and policy determination, the most useful population to study is usually the resident population of an area. In the case of vital events, the existence of resident certificate exchange agreements among the registration areas in the country permits analysis of resident vital event statistics regardless of where the event occurred. In the query system, the data presented represent fetal deaths to New Jersey resident mothers, regardless of where they occurred. Fetal deaths that occurred in New Jersey to non-NJ residents are not included.

Allocation of vital events by place of residence within the state is sometimes difficult because classification depends on the statement of the usual place of residence provided by the informant at the time the certificate is completed. For a variety of reasons, the information given may be incorrectly recorded. A common source of error is the confusion of mailing address with residence address. For this reason, all records are run through geocoding software to properly assign the county and municipality of residence.
Race, ethnicity, and nativity used in the Fetal Mortality Query are that of the mother. See the Birth Data Technical Notes for more information on maternal race, ethnicity, and nativity.
Rankable causes of death in the fetal mortality query are based on 45 distinct causes of death derived from the NCHS List of 124 Selected Causes of Fetal Death.
The presentation of fetal mortality rates facilitates comparisons between geographic areas with populations of different sizes or between subgroups of a population. Fetal mortality rates are calculated by dividing the number of fetal deaths of 20 or more weeks gestation to resident mothers of an area or demographic subgroup by the number of births plus fetal deaths of 20 or more weeks gestation to the residents of the same area or subgroup and are usually expressed per 1,000 births plus fetal deaths of 20 or more weeks gestation. Fetal deaths are limited to those that occur within a specific time period, usually a year, and the birth data used for rate calculation is that of the same year.

In order to compare fetal death experiences among various maternal ages and races/ethnicities, fetal mortality rates may be computed for subgroups of the population. These are referred to as age- or race/ethnicity-specific rates and are calculated by dividing the number of fetal deaths of 20 or more weeks gestation within a subgroup by the births plus fetal deaths of 20 or more weeks gestation in the subgroup. Fetal death rates from specific causes may also be calculated, with the numerator consisting of the deaths from the particular cause in an area and the denominator comprised of births plus fetal deaths of 20 or more weeks gestation in the same time period.

The definition of rates used in the query system are on the Definitions of Public Health Terms and Acronyms page . It should be noted that alternative forms exist for some of these statistics. Some other states and the federal government may employ different formulae for the computation of selected rates.
Caution should be exercised in the interpretation of rates based on small numbers. Chance variations in the number of fetal deaths occurring in sparsely populated areas can cause rates to fluctuate widely over time. In accordance with NCHS standards, rates based on fewer than 20 fetal deaths or fewer than 20 births in the denominator are considered unreliable for analysis purposes. Therefore, these rates are not displayed and are indicated by ** in the appropriate cell. For purposes of analyzing fetal mortality rates for small areas, calculation of three- or five-year average rates and other statistical methodologies for analyzing small numbers may provide more meaningful measures.
The information provided above is from the Department of Health's NJSHAD web site ( The information published on this website may be reproduced without permission. Please use the following citation: " Retrieved Sun, 14 August 2022 2:21:40 from Department of Health, New Jersey State Health Assessment Data Web site: ".

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