1) The stillbirth rate is the number of stillbirths divided by the number of pregnancies of seven or more months' duration (all live births plus stillbirths).
2) The early neonatal mortality rate is the number of early neonatal deaths divided by the number of pregnancies of seven or more months' duration (all live births plus stillbirths).
3) The perinatal mortality rate is the sum of the number of perinatal deaths (stillbirths and early neonatal deaths) divided by the number of pregnancies of seven or more months' duration (all live births plus stillbirths).
Coverage:
Population base: Pregnancies of seven or more months to women age 15–49 at time of survey (IR file, BR file)
Time period: Five-year period preceding the survey (v008 to v008-59)
Numerator:
1) Stillbirth rate: Number of fetal deaths in pregnancies of 28 weeks or more or seven or more months
2) Early neonatal mortality: Number of deaths of live-born children in the 0–6 days following birth
3) Perinatal mortality: Number of fetal deaths in pregnancies of seven or more months plus number of deaths of live-born children in the 0–6 days following birth
4) Ratio of stillbirths to early neonatal deaths: See numerator 1 and 2 above.
Denominator:
a) Number of pregnancies of 28 weeks or more (or seven or more months) that terminated in a fetal death plus pregnancies that ended with a live birth
b) Number of live-born children born in the time period
c) Number of pregnancies of 28 weeks or more (or seven or more months) that terminated in a fetal death plus pregnancies that ended with a live birth
d) See numerator 2 above
Variables: IR file, BR file.
DHS-7 and prior
|
vcal_1 |
Calendar |
|
v008 |
Date of interview (CMC) |
|
v018 |
Row (position) in calendar of month of interview |
|
b3 |
Date of birth of child (CMC) |
|
b5 |
Child is alive (1 = yes, 0 = no) |
|
b7 |
Age at death in months (imputed) |
|
v005 |
Woman’s individual sample weight |
DHS-8
|
p3 |
Date of end of pregnancy (CMC) |
|
p19 |
Months since pregnancy outcome |
|
p20 |
Duration of pregnancy |
|
p32 |
Pregnancy outcome |
|
v005 |
Woman’s individual sample weight |
DHS-7 and earlier surveys
For DHS-7 and earlier surveys the perinatal mortality rate was calculated as the quotient of the sum of the two parts of the numerator (stillbirths plus early neonatal deaths) divided by the sum of the two parts of the denominator (stillbirths plus all live births), as follows:
Numerators:
The sum of the number of stillbirths plus the number of early neonatal deaths in the five years preceding the survey.
a) Number of stillbirths: From the reproductive calendar, number of pregnancies that lasted seven or more months and terminated in a fetal death in the five years preceding the survey.
· For each position in the calendar (vcal_1) from v018 to v018+59: tally stillbirth if there is a “T” (termination) in the position followed by six “P”s (pregnancy) (“TPPPPPP”).
b) Number of early neonatal deaths: Number of children who died at age 0–6 days after birth in the five years preceding the survey.
· For births in the birth history tally all early neonatal deaths (b6 in 100:106) if the birth took place in the five years preceding the survey (v008 >= b3 >= v008-59).
Denominators:
The sum of the number of stillbirths plus the number of live births in the five years preceding the survey.
a) Number of stillbirths, given in numerator 1 above.
b) Number of live births in the five years preceding the survey (v008 >= b3 >= v008-59).
Perinatal mortality rate: Quotientof numerator divided by denominator multiplied by 1000.
DHS-8
In DHS-8 surveys, the perinatal mortality rate and the stillbirth rate are calculated in a conceptually similar manner to the approach used in DHS-7 but use a different source of information, namely the pregnancy history, rather than the calendar for the information related to stillbirths, with pregnancy durations reported in weeks or months, rather than just months. This also allows the counting of stillbirths from twins, either as a live birth and still birth, or twin stillbirths, and may result in a slightly higher estimate of perinatal mortality than was possible with the prior approach.
Numerator:
1) Number of stillbirths: From the pregnancy history, number of pregnancies that lasted 28 or more weeks (or seven or more months) and terminated in a fetal death in the five years preceding the survey.
· For each pregnancy in the pregnancy history with p3 from v018 to v018+59: tally stillbirth if the pregnancy outcome was “born dead” (p32 = 2) and the duration of the pregnancy was 28 weeks or more (or 7 months or more) (p20 in 128:150,207:211).
2) Number of early neonatal deaths: Number of children who died at age 0–6 days after birth in the five years preceding the survey.
· For births in the birth history tally all early neonatal deaths (b6 in 100:106) if the birth took place in the five years preceding the survey (v008 >= b3 >= v008-59). This part is unchanged from DHS-7.
3) Sum of numerator 1 and numerator 2.
Denominators:
4) The sum of:
a) Number of stillbirths, as calculated in numerator 1, and
b) Number of live births in the five years preceding the survey (v008 >= b3 >= v008-59).
5) Number of live births in the five years preceding the survey (v008 >= b3 >= v008-59).
6) Same as denominator 1.
Calculation:
1) Stillbirth rate: Quotient of numerator 1 divided by denominator 1 multiplied by 1000.
2) Early neonatal mortality rate: Quotient of numerator 2 divided by denominator 2 multiplied by 1000.
3) Perinatal mortality rate: Quotient of numerator 3 divided by denominator 3 multiplied by 1000.
4) Ratio of stillbirths to early neonatal deaths: Quotient of indicator 1 divided by indicator 2.
Missing values are not allowed for any of the variables that make up the rate. Age at death for children who died is imputed if unknown or missing.
The perinatal mortality rate is defined by dividing the number of perinatal deaths (stillbirths and early neonatal deaths) by either the number of live births or by the sum of live births and stillbirths. Both definitions are prevalent in the literature. The DHS Program has chosen to report the latter.
The definition of the pregnancy duration for stillbirth in general has changed in the literature over time. Originally, it was pregnancies lasting 28 weeks that ended in a fetal death. The duration limit was subsequently lowered to 24, 22, and even 20 weeks. For the purpose of calculating perinatal mortality, however, the definition remains at 28 weeks. DHS asks and records pregnancy duration in weeks or months. The durations of pregnancy are taken as reported by the respondents and do not necessarily have a clinical basis.
In DHS-7 and earlier surveys, the number of stillbirths was estimated from the Contraceptive Calendar. See the Contraceptive Calendar Tutorial at https://www.dhsprogram.com/data/Calendar-Tutorial/index.cfm for a description of the calendar, how the data are stored and how to analyze the calendar data, and videos on Completing the Contraceptive Calendar and the Data Structure of the Contraceptive Calendar. See particularly Example 4: Still births and perinatal mortality at https://www.dhsprogram.com/data/Calendar-Tutorial/index.cfm#example4. In DHS-8, the number of stillbirths is calculated from the pregnancy history.
Earlier DHS reports prior to about 1998 used a somewhat different basis for perinatal rates. Deaths of live-born children were considered early neonatal deaths if they occurred 0 to 7 days after birth, given the large amount of heaping on day 7 and the consideration of the likelihood of rounding “in the first week of life” by interviewers to seven days, due to questionnaire coding requirements. In more recent years The DHS Program has used the stricter definition of 0 to 6 days. Also, the denominator for the rates was previously the number of live births rather than the sum of live births and stillbirths.
In DHS-7 and earlier surveys, the number of stillbirths was estimated from the Contraceptive Calendar and excluded stillbirths that were twins of live births, or pairs or triplets of stillbirths as the contraceptive calendar only allowed for a single entry in each month. In DHS-8 a pregnancy history is used, and this captures all stillbirths including those that are twins of live births or pairs or triplets of stillbirths, and thus estimates of stillbirths and perinatal mortality may be slightly higher than those reported in earlier surveys.
DHS Contraceptive Calendar Tutorial. Example 4 – Still births and Perinatal Mortality. https://www.dhsprogram.com/data/Calendar-Tutorial/index.cfm#example4
DHS-8 Tabulation plan: Tables 8.4
API Indicator IDs:
CM_PNMR_C_PMR
(API link, STATcompiler link)
DHS Contraceptive Calendar Tutorial: https://www.dhsprogram.com/data/Calendar-Tutorial/index.cfm
DHS Contraceptive Calendar Tutorial Video Part 1: Completing the Contraceptive Calendar https://www.youtube.com/watch?v=_7V6S5ljnZc
DHS Contraceptive Calendar Tutorial Video Part 2: Data Structure of the Contraceptive Calendar https://www.youtube.com/watch?v=T2pS8IM0jyU