Noninvasive fetal RhD status determination in early pregnancy.

INTRODUCTION: The aim of this study was to examine if noninvasive fetal RhD genotyping from maternal blood cell-free fetal DNA performed in the first trimester of pregnancy is accurate enough to propose its routine application to replace usual immunoprophylaxis. MATERIAL AND METHODS: We carried out a prospective study analyzing fetal RhD genotype in 149 nonimmunized RhD-negative women with single pregnancies between 8 and 13 weeks of gestation. Fetal RhD genotype was detected by quantitative PCR targeting exons 5 and 7. The results were compared with postnatal cord blood phenotype, and discrepancy rates were calculated. RESULTS: The concordance of fetal RhD genotypes in maternal plasma and newborn D phenotypes at delivery was 98.2%, including 1 false-positive and 1 false-negative result. The specificity and sensitivity of the assay were 97.5% (95% CI 87.1-99.9) and 98.6% (95% CI 92.7-99.9), respectively, and 6.5% of the results were inconclusive. The application of this test in early pregnancy would avoid unnecessary antenatal prophylaxis in about 27% (40/143) of nonsensitized RhD-negative women. DISCUSSION: Determination of the fetal RhD status from cell-free fetal DNA in maternal plasma in the first trimester of pregnancy is feasible and highly accurate, thus allowing consideration of replacing general routine immunoprophylaxis in the cases of mothers with Rh-negative fetuses.

Risk of episiotomy and perineal lacerations recurring after first delivery.

BACKGROUND: To assess whether the presence of an episiotomy or spontaneous perineal trauma at the first delivery increases the risk of perineal trauma at the following one. METHODS: We studied 2,695 women who gave birth twice at Virgen de las Nieves University Hospital of Granada, Spain. All second deliveries were from 2004 to 2011 and prenatal database records were used to obtain information about the first deliveries. All births, first and second, were single, vaginal, unassisted, and in a cephalic presentation. Two groups were made as follows: Intact perineum (no perineal trauma or first-degree spontaneous tear at the first delivery) and perineal trauma (episiotomy or second-degree or higher spontaneous tear at the first delivery). Both groups were compared according to the degree of perineal trauma at the second delivery. RESULTS: Women included in the perineal trauma group were significantly older and a higher proportion was attended by a midwife with an obstetrician present in the delivery room. No differences were observed according to gestational age, epidural analgesia or fetal birth weight. Adjusting for these possible compounding factors and the year of birth, the risk of undergoing a second-degree or higher spontaneous tear at their next delivery was fivefold (adjusted OR 5.15, 95% CI 3.11-8.54), and the risk of undergoing an episiotomy in the second delivery was threefold (adjusted OR 3.20, 95% CI 2.19-4.69) for the perineal trauma group. CONCLUSION: The risk of undergoing a spontaneous perineal tear or an episiotomy in the second delivery is increased by the practice of episiotomy in the first one.