Background. Published literature has provided unclear evidence on the association between maternal delivery position and risk of perineal laceration. While much research has been done on this topic in the hospital setting, the frequencies of both delivery positions and perineal lacerations have not been determined for the women who deliver at home or in a birth center with midwives who contribute to the MANAstats database.

Methods. Basic descriptive statistics of the MANAstats 2.0 dataset were run using SPSS. The data was delimited for primiparous women who delivered term vertex singletons at home or in a birth center with a midwife. Findings were compared with that of the published research.

Results. This study included 788 cases. Of those, 69.2% (n=545) of women had any perineal, labial, cervical or vaginal trauma. Of the women who sustained a perineal laceration, 45.5% (n=247) sustained a 1st degree laceration, 34.4% (n= 187) sustained a second degree laceration, 1.1% (n=6) sustained a 3rd degree laceration, and 0.6% (n= 3) sustained a 4th degree laceration. Semi-sitting was the most frequent delivery position (33.0%; n=260), 16.1% (n=127) delivered in the hands-and-knees position, 12.6% (n=99) of women delivered on a birth stool, 10.5% (n=83) of women delivered in the squatting position, 9.4% (n=74) of women delivered on their side, 6.5% (n=51) of women delivered in an "other" position, 4.4% (n=35) delivered in McRoberts, 4.3% (n=34) delivered on their backs, and 3.2% (n=25) delivered standing. Standing had the highest rate of intact perineum (27.8%, n=5); squatting had the lowest rate (9.1%, n=6). Squatting had the highest rate of first degree perineal laceration (56.1%, n=37); semi-sitting had the lowest rate (29.6%, n=77). Delivering on back had the highest rate of second degree perineal laceration (42.9%; n=9); standing had the lowest rate (27.8%, n=5). The number of third- and fourth-degree perineal lacerations was small, 1.1% (n=6) and 0.6% (n=3) respectively.

Conclusions. Primiparas who delivered at home or in a birth center with midwives who were contributors to the MANAstats 2.0 dataset were more likely to utilize physiological (upright) positions than those reported in previously published studies on women who delivered in the hospital setting. However, the rate of second-degree laceration was similar to that of the published literature for home, birth center, and hospital deliveries. Therefore, women should not be discouraged from delivering in a position they find comfortable based on risk of perineal laceration.