Defining the perinatal mortality rate
The perinatal mortality rate measures deaths around the time of birth. Its numerator combines fetal deaths at 28 weeks of gestation or more (late fetal deaths) and early neonatal deaths, which are deaths in the first 7 days of life. Its denominator is total births: live births plus those same fetal deaths. The numerator and denominator both include the late fetal deaths, because these babies were part of the population at risk of dying around birth.
Working the numbers
The municipality recorded 960 live births and 8 fetal deaths at 28 weeks or more. Of the 24 infant deaths, 15 occurred in the first 28 days and 10 of those in the first 7 days. Only the 10 early neonatal deaths belong in the numerator. Perinatal mortality rate = (8 + 10) ÷ (960 + 8) × 1,000 = 18 ÷ 968 × 1,000 = 18.6 per 1,000 total births. The rest of the data, including the 24 infant deaths and the 15 neonatal deaths, are distractors for this calculation.
| Indicator | Numerator | Denominator | Result |
|---|
| Perinatal mortality rate | Fetal deaths 28 wk+ and deaths under 7 days (18) | Live births + fetal deaths (968) | 18.6 |
| Neonatal mortality rate | Deaths under 28 days (15) | Live births (960) | 15.6 |
| Early neonatal deaths over live births | Deaths under 7 days (10) | Live births (960) | 10.4 |
| Infant mortality rate | Deaths under 1 year (24) | Live births (960) | 25.0 |
How each distractor was built
10.4 uses only the early neonatal deaths over live births and leaves out the fetal deaths in both numerator and denominator. 15.6 is the neonatal mortality rate, which counts deaths up to 28 days and includes no fetal deaths. 23.8 adds fetal deaths to all 15 neonatal deaths instead of only the 10 deaths in the first week, so it extends the perinatal period to 28 days. Watch out! The word perinatal means around birth, and its newborn component stops at 7 days, not 28 days.
Exam takeaway
For the perinatal rate, add late fetal deaths to the numerator and to the denominator, and count only the first 7 days of life. This indicator reflects the quality of prenatal, intrapartum, and immediate newborn care, so a high value directs the RHU toward antenatal checkups, skilled birth attendance, and essential newborn care. When rounding, carry the full division (18 ÷ 968 = 0.01859...) before multiplying and rounding to one decimal place.