European Journal of Cardiovascular Medicine

The fluid that surrounds the foetus in utero is called Amniotic fluid. Transudation from maternal circulation, Amniotic membranal active section , Fetal secretions, such as those from the mouth, nose, trachea, and lungs, are the main source of its production. Foetal ingestion and membrane absorption are the main methods of removal . The dynamic equilibrium of the previously stated mechanisms determines the amount of amniotic fluid in the gestational sac.

Main functions of Amniotic fluid during pregnancy are provides cushion against trauma and protects foetus, allows growth of foetus by providing free space and free movement , maintains in utero temperature , nutritive function and helps in growth and differentiation of gastrointestinal tract and respiratory tract .

Main functions during labour by providing hydrostatic wedge for cervical dilatation and prevents decrease in placental circulation during uterine contractions.

Additionally, it is essential for assessing foetal lung maturity, and helping in the prenatal detection of structural and chromosomal abnormalities and is an important component of Biophysical profile (BPP) which is a test for foetal wellbeing.

To calculate Amniotic fluid we use ultrasound and Amniotic fluid index is calculated . Oligohydramnios is defined as AFI less than 5cm and Borderline Oligohydramnios as AFI 5.1 to 8 cms .

Various conditions leading to Oligohydramnios are foetal genitourinary abnormalities like renal agenesis , renal dysplasia ,bladder extrophy , TRAP, VACTER abnormalities  fetal gastrointestinal abnormalities , postterm pregnancy , uteroplacental insufficiency , maternal conditions such as hypertension , cardiac disease , inadequate hydration etc .

Increased maternal and neonatal morbidity and mortality are linked to oligohydramnios, which is associated with poor pregnancy outcomes. Preterm delivery, pulmonary hypoplasia, low APGAR scores, meconium passage, structural abnormalities, poor labour progress, an increase in the number of caesarean sections, and neonatal intensive care unit (NICU) admissions are a few of these.

Even though oligohydramnios has a wide range of causes, it can occasionally be observed in foetuses that are appropriate for their gestational age and free of maternal or foetal diseases. We refer to these cases as isolated oligohydramnios (IO).

Since isolated oligohydramnios is typically linked to inadequate maternal fluid intake, increasing the mother's oral fluid intake can improve the prognosis. There are, however, fewer research comparing the advancements made in hospital and home environments, particularly among Indian populations. In order to evaluate the improvement in AFI and perinatal outcomes after maternal oral hydration therapy in both home and hospital settings, this study was carried out.

Study site: This study was conducted in the Department of Obstetrics and Gynaecology in Konaseema Institute of Medical Sciences and Research Foundation , Amalapuram.

Study population : 50 cases of isolated borderline oligohydramnios (other high-risk pregnancy conditions not present) were included in the study (25 in home group and 25 in hospital group).

Study design : The current study is a prospective study.

Sample size :  50 (25 in home group and 25 in hospital group).

 Study duration : The present study is conducted during period from 1 st February 2023 to 31th January 2024 ( 1 year ) .

Inclusion criteria:

All non-high-risk, singleton pregnancies with borderline oligohydramnios ( AFI 5cm to 8cm ) .

Women with non-high-risk, singleton pregnancy with intact membranes, without any medical disorders with no congenital foetal anomalies, who were diagnosed as isolated oligohydramnios clinically and confirmed on ultrasonography through AFI of less than 8 cm, were included in the study.

Exclusion criteria:

Women with structural foetal malformation, maternal diseases as cardiac disease, pre-eclampsia, eclampsia, renal impairment, severe anaemia, diabetes, thyroid disorders, multiple pregnancy, premature and prelabour rupture of membranes were excluded from the study Patients refusing to consent for the study were also excluded.

Ethical consideration:

Study was approved by institutional human ethics committee.

Informed written consent was obtained from all the study participants and only those participants willing to sign the informed consent were included in the study.

The risks and benefits involved in the study and voluntary nature of participation were explained to the participants before obtaining consent.

Confidentiality of the study participants was maintained.

Methodology:

AFI is measured by four quadrant technique on ultrasonography by dividing the maternal abdomen into four quadrants, the linea nigra was used to divide abdomen into right and left halves and umbilicus was used to separate upper and lower halves.  The largest amniotic fluid pocket (anechoic) was identified in each quadrant free of foetal limbs and cord loops and its vertical diameter was taken. All four vertical diameters were added to obtain AFI in centimetres.

The selected cases were subjected to detailed history, general, systemic and obstetrical examination.

 Antenatal investigations were done especially to rule out systemic medical disorders.

 Written informed consent was taken from each selected case after thoroughly explaining about oral hydration therapy.

Antenatal patients who were diagnosed to have borderline oligohydramnios (AFI of 5 cm to 8 cm) in the third trimester and who met the inclusion and exclusion criteria were included in the study. Ultrasound-confirmed moderate oligohydramnios (when AFI is 5 cm to 8 cm) cases are taken. All non-high-risk, singleton pregnancies with oligohydramnios were included.

50 cases of isolated borderline oligohydramnios (other high-risk pregnancy conditions not present) were included in the study (25 in home group and 25 in hospital group).

Antenatal women enrolled in the study were assigned one of the two groups by randomization , namely,

• 25 cases in home group
• 25 cases in hospital group

The baseline AFI at day 1 was recorded for all the patients. Patients were encouraged for an additional 2 litres of oral rehydration solution, water, coconut water or fruit juices intake daily along with regular diet and fluids.  The fluid intake was unsupervised in the home group and supervised in the hospital group  Amniotic fluid index was re-evaluated by ultrasonography done at 48 hours of oral hydration therapy.  Difference in prehydration and post-hydration AFI was calculated. In addition to their usual fluid intake, women were urged to continue drinking two litres extra fluid per day orally until delivery.Mode of delivery  and APGAR score was recorded.

Demographic profile of patients:

The mean age of the women was 23.2 years and majority (64%) belonged to low socioeconomic status .  Oligohydramnios was found to be more common in primigravida (40%).  Most of the women selected for the study belonged to 32 to 36 weeks gestational age (52%).

Home hydration group

P VALUE :0.000008

As p value is <0.05 it is statistically significant .

Maximum number of women (92%) had pretreatment AFI between 6 and 7 . After 48 hours of oral hydration therapy, none of the women were having severe oligohydramnios (i.e. AFI < 5) and majority (80%) had AFI between 7 and 8. Mean prehydration AFI was 6.44 ± 0.65 cm while the mean posthydration AFI at 48 hours was 7.4 ± 0.76 cm. P value is <0.0001 , less than 0.05 , so statistically significant.

Hospital hydration group:

P value :0.000007

As p value <0.05 it is statistically significant.

Maximum number of women (80%) had pretreatment AFI between 6 and 7 . After 48 hours of oral hydration therapy, none of the women were having severe oligohydramnios (i.e. AFI < 5) and majority (84%) had AFI between 7 and 8. Mean pre hydration AFI was 6.08 ± 0.70 cm while the mean post hydration AFI at 48 hours was 7.92 ± 0.64 cm. P value is <0.0001 , less than 0.05 , so statistically significant.

Post hydration AFI:

Here the AFI is increased more in hospital group who were supervised in comparison to home group .

Mode of delivery:

Out of 50 women of isolated oligohydramnios, vaginal delivery occurred in 36% cases while 8% required assisted instrumental vaginal delivery . Elective caesarean section was performed in 24% cases while 36% women underwent emergency caesarean section. In women with AFI < 7, 18/24 (75%) required caesarean section. In women with AFI > 7 ,  10/26 (38.4%) required caesarean section in women with and this was found to be statistically significant (p = 0.0002).

The reduced volume of amniotic fluid surrounding the fetus in the amniotic cavity is known as oligohydramnios. Low amniotic fluid volume without any maternal or fetal disorders is referred to as "isolated oligohydramnios." We selected the cases of isolated oligohydramnios for evaluating the effect of oral hydration therapy on AFI and neonatal outcome.

In our study, isolated oligohydramnios was more common in primigravida (40%). Garmel et al found 67% while Jandial et al found 60% of the women to be nulliparous with isolated oligohydramnios. Most of the isolated oligohydramnios (52%) belonged to 32 to 36 weeks gestational age group.

Oral maternal hydration therapy is a simple, noninvasive, safe, and trouble-free method of treating oligohydramnios.

The mean AFI increased from 50.8 to 67.2 mm (p < 0.001) with maternal oral hydration therapy, according to Ghafarnejad.

In contrast, it increased from 62.6 mm to 76.5 mm in just 48 hours in the current study.

Researchers have found that oral hydration raises the AFI by 2.01 cm (95% Cl; 1.43-2.56) in oligohydramnios and 4.5 cm (95% Cl; 2.9-6.1) in normal pregnancy. Similar findings were published by Fait et al., who noted that when mothers continue to drink "2" litres of fluid every day for a week, the short-term increase in amniotic fluid volume lasts into the long term when they continue drinking the same. After 48 hours, the mean AFI rose to 7.92 ± 0.62 cm, confirming this in the current investigation .The gestational age at time of oral hydration and the amount of time until birth determine whether or not there is improvement in AFI in isolated oligohydramnios .

Sixty percent of the cases in our study had caesarean sections. Insufficient time for hydration and other obstetrical variables like continuous intrapartum monitoring caused high caesarean rate in our study. In their study, Rawat et al reported 48% caesarean section rate, Jandial et al. reported a 56% cesarean section rate, but Bangal et al. reported 44%.All newborns had APGAR scores in the range of 7-9/10.Our investigation found no infant mortality during the intrapartum or postpartum period.

In isolated oligohydramnios instances, maternal oral hydration therapy is an easy, safe, non invasive, and efficient way to increase the volume of amniotic fluid; however, it must be administered continuously over an extended period of time in order to enhance the neonatal outcome.
By increasing the volume of amniotic fluid, maternal oral hydration therapy enhances the perinatal outcome.
The implementation of supervised hydration therapy is advised due to inadequate adherence to home-based treatment.

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