Frequency of denial of pregnancy: results and epidemiological significance of a 1-year prospective study in Berlin.

Abstract

There has been an increasing number of reports on denial of pregnancy. However, only very few studies have involved a large number of patients. To date, no reliable calculation of this condition's general frequency, also from an epidemiological perspective, has been available. A prospective case sampling was performed between 1 July 1995 and 30 June 1996 in the metropolitan area of Berlin. All institutions in which deliveries have taken place were engaged. The lower limit for inclusion was the 20th week of gestation as the first physician's earliest diagnosis of pregnancy. Furthermore, the woman herself must not have had any subjective perception. Recruited women were divided into three groups. Altogether 62 cases and 29 462 deliveries within the 1-year study period were valid for the frequency calculation, leading to a ratio of 1 : 475 (all cases) and of 1 : 2455 for totally unexpected births with a viable newborn (intrapartal diagnosis of the pregnancy). This first prospective, population-based study has also certain epidemiological relevance. From projecting the ratio of 1 : 475 for all of Germany, approximately 1600 cases of denied pregnancies per year are diagnosed, at the earliest, from the 20th week of gestation. Totally unexpected deliveries of a viable fetus without any presumption of being pregnant with 300 projected yearly births would occur threefold more often than triplets. Occurrence of denied pregnancy seems yet to be similar across different socio-demographic conditions. The common view that denied pregnancies are exotic and rare events is no longer valid. More studies of similar design are needed.