Question

An investigator examined cases of fetal death in 27,000 pregnancies and classified mothers according to whether they had experienced sexual intercourse within 1 month before delivery. It was found that 11% of the mothers of fetuses that survived had had sexual intercourse during the period. It was concluded that intercourse during the month preceding delivery caused the fetal deaths.

This conclusion:

a) May be incorrect because mothers who had intercourse during the month before childbirth may differ in other important characteristics from those who did not.
b) May be incorrect because there is no comparison group.
c) May be incorrect because prevalence rates are used where incidence rates are needed.
d) May be incorrect because of failure to achieve a high level of statistical significance.
e) Both b and c.

Answer 1

The correct answer is option A.

Explanation:

Fetal deaths imply the death of a fetus The death of a fetus at or after 28 weeks of pregnancy is known as a stillbirth. Usually, fetal deaths are associated with complications during pregnancy, sexual intercourse during pregnancy, infections, smoking, poor health in mother, drug abuse, e.t.c.

However, recent studies conclude that in an uncomplicated pregnancy, sexual intercourse during pregnancy is not harmful to the fetus or the mother.

Due to sexual intercourse, 11% of the mothers had fetal deaths. However, when compared, 2.5% of mothers who also experienced sexual intercourse before childbirth had survived fetuses.

The prevalence rate gives the number of affected individuals in the population, whereas, the probability of an individual being diagnosed with a specific condition and from a limited sample size. The statistical significance can be obtained based on how well the sample is measured.

Thus, the options b,c,d, and e are incorrect.

The mothers who experienced fetal deaths due to sexual intercourse, when compared to those mothers who had survived fetuses may differ in other characteristics such as issues with placenta or umbilical cord, malaria, or mothers age above 35.

So, the correct answer is option A.