Perinatal outcomes among three types of vasa previa: Nationwide survey in Japan

To clarify whether the maternal backgrounds and perinatal outcomes of the three types of vasa previa (VP) differ based on placental location and cord insertion.

A retrospective questionnaire survey of VP cases in all 408 perinatal centers in Japan was conducted. The survey covered the clinical information of VP cases, including maternal characteristics, prenatal management, and perinatal outcomes, between January 2020 and December 2022. These backgrounds and events were compared among the three types of VP.

Two-hundred and seventy-nine cases of VP were analyzed. The type of VP was confirmed postnatally in 254 cases. The rates of confirmed type diagnoses were 67.7 % of Type 1, 17.7 % of Type 2, and 14.6 % of Type 3. Pre- and postnatal VP type diagnoses matched in 97.6, 92.6, and 76.5 % of cases of Types 1, 2, and 3, respectively. A low-lying placenta was less common in Type 1 (29.1 %) than in Type 2 (51.1 %) and Type 3 (45.9 %), while no significant differences were observed in other maternal characteristics. In all cases, VP was diagnosed prenatally with a high probability (Type 1: 98.8 %, Type 2: 95.6 %, Type 3: 100 %). There were no cases of fetal or neonatal death. Furthermore, no significant differences were noted in pre- or perinatal management or in the frequency of poor short-term perinatal outcomes (e.g., the rate of umbilical artery pH < 7.2 and Apgar score 5 mins < 7).

In all VP types, VP was diagnosed prenatally in > 95 % of cases. A low-lying placenta was less common in Type 1 VP, while no significant differences were observed in maternal backgrounds or short-term perinatal outcomes among the three types of VP.