Oligohydramnion in the First Half of Pregnancy in the Fetuses with Congenital Abnormalities: Ultrasound Diagnostics and Obstetric Outcomes

Background. Oligohydramnion in the first half of pregnancy, combined with congenital abnormalities in the fetus has objective difficulties in diagnosis. The morphology features and type of defects associated with oligohydramnion, which manifests in the first half of pregnancy, are not sufficiently studied at the present stage. 

Aims — to evaluate the clinical significance of diagnosing oligohydramnion in the first half of pregnancy in women with congenital fetal malformations. 

Materials and methods. The analysis of the course of pregnancy and perinatal outcomes in 77 women with low water content in combination with congenital malformations of the fetus and 72 patients with a normal amount of amniotic fluid and no congenital malformations of the fetus was performed. The patients of the main group were divided into two subgroups depending on the severity of oligohydramnion: the 1st subgroup (n = 54) —patients with severe oligohydramnion and the 2nd subgroup (n = 23) — patients with moderate oligohydramnion. The amount of amniotic fluid was determined by 3D/4D ultrasound (13–21 weeks of gestation) and the structure of fetal abnormalities associated with oligohydramnion was analyzed. We evaluated perinatal outcomes in women with congenital malformations of the fetus in combination with oligohydramnion and the effect of its severity on the outcome of pregnancy. 

Results. In the main group (n = 77), fetal abnormalities were detected in patients: urinary system — 39 (50.6%), respiratory system — 4 (5.2%), heart — 1 (1.3%), chromosomal and genetic abnormalities — 14 (18.2%), central nervous system — 3 (3.9%), osseous system — 3 (3.9%), multiple — 13 (16.9%). In the main group (n = 77), pregnancy was terminated for medical indications in 47 (61%) cases, in 6 (7.8%) spontaneous miscarriage occurred, in 5 (6.5%) — antenatal fetal death. 19 (24.7%) children were born alive, and surgical treatment in the neonatal period was required in 8 (10.4%) cases. In the 1st subgroup (n = 54) in 53 (98.1%) cases, there was a loss of the fetus, in 1 (1.9%) — the newborn died on the 9th day. In the 2nd subgroup (n = 23), fetal death occurred in 5 (21.7%) cases, 18 (78.3%) children were born alive, and 8 (44.4%) newborns were operated on in the neonatal period. In the control group, all pregnancies ended with the birth of healthy children. A decrease in ultrasound imaging of internal organs in the fetus was observed when a pregnant woman was obese (BMI more than 35). 

Conclusions. Oligohydramnion in the first half of pregnancy in combination with fetal malformation should be considered an extremely unfavorable clinical sign for the prognosis of pregnancy and the health of the fetus and newborn. 3D/4D ultrasound scanning allows you to reliably determine oligohydramnion in the first half of pregnancy, and the degree of its severity to assume the nature of complications.