Influence of oligohydramnios in late preterm on the mode and outcome of pregnancy

Objective To investigate the influence of oligohydramnios on the mode and outcome of pregnancy in late preterm. Methods Forty-six pregnant women with reduction of amniotic fluid volume in the late trimester of pregnancy who gave birth in Jiexiu Maternal and Child Health Care Planning Service Center from March 2016 to December 2017 were selected as observation group, and 46 cases of pregnant women with normal amniotic fluid volume in the same period were selected as control group. Non-stress test (NST) score, the ratio of systolic to diastolic (S/D), delivery mode, and pregnancy outcome were compared between the two groups. Pregnancy outcome and delivery mode were compared among pregnant women with different degrees of amniotic fluid reduction. Results The ratio of S/D ≥3.0 in observation group was higher than that in control group (P 0.05); the rate of caesarean section in observation group was significantly higher than that in control group, and the cesarean section rate in pregnant women with a borderline amniotic fluid was higher than that in pregnant women with oligohydramnios (P<0.05). The proportion of amniotic fluid grade Ⅲ pollution, neonatal asphyxia and low weight infants of observation group was significantly higher than that of control group (P<0.05). Compared with the women with a borderline amniotic fluid, the incidence of amniotic fluid grade Ⅲ pollution and rate of low weight infants were higher in pregnant women with oligohydramnios (P<0.05). Conclusions The decrease of amniotic fluid volume during the third trimester will increase the rate of cesarean section and the incidence of low weight infants, and the incidence will continuously increase with the decrease of amniotic fluid volume. Key words: Late pregnancy; Oligohydramnios; Delivery mode; Pregnancy outcome