Reference ranges of amniotic fluid index in late third trimester of pregnancy: what should the optimal interval between two ultrasound examinations be?

Does the Summer Season Affect the Amniotic Fluid Volume during Pregnancy?

Amniotic fluid is crucial for the well-being of the fetus. Recent studies suggest that dehydration in a pregnant woman leads to oligohydramnios. We assessed the variation in the amniotic fluid index (AFI) during the summer and non-summer seasons and evaluated neonatal outcomes. We retrospectively reviewed electrical medical records of pregnant women who visited the Konkuk University Medical Center for antenatal care, between July 2005 and July 2019. A total of 19,724 cases from 6438 singleton pregnant women were included after excluding unsuitable cases. All AFI values were classified as 2nd and 3rd trimester values. Additionally, borderline oligohydramnios (AFI, 5–8) and normal AFI (AFI, 8–24) were assessed according to the seasons. The average AFI between the summer and non-summer season was statistically different only in the 3rd trimester; but the results were not clinically significant. In the 3rd trimester, the summer season influenced the increased incidence of borderline oligohydramnios. The borderline oligohydramnios group showed an increased small-for-gestational-age (SGA) rate and NICU admission rate. In the summer season, the incidence of borderline oligohydramnios was seen to increase. This result would be significant for both physicians and pregnant women.

Correlation of perinatal outcomes with amniotic fluid assessment techniques in high-risk pregnancies in a Tertiary Hospital in Southern Nigeria

BACKGROUND

Oligohydramnios is a predictor of fetal compromise and a useful tool in pregnancy management. It has been assessed using various techniques, including two-diameter pocket (2-DP) and amniotic fluid index (AFI).

OBJECTIVES

To determine which of these two techniques best diagnose oligohydramnios and predicts adverse perinatal outcomes.

METHODS

This was a comparative cross-sectional study conducted at Delta State University Teaching Hospital, Oghara in southern region of Nigeria over eight months period. One hundred high-risk pregnant women were recruited and ultrasound determination of amniotic fluid was performed using AFI and 2-DP. The women were followed up till delivery to determine adverse perinatal outcomes.

RESULTS

The indices of validity of AFI and the 2-DP were calculated and compared. The 2-DP had a higher sensitivity than AFI for adverse outcomes in high-risk pregnancies complicated by oligohydramnios.

CONCLUSION

The 2-DP technique should preferably be used for the assessment of oligohydramnios in high-risk pregnancies.

Association Between Fetal Middle Cerebral Artery and Umbilical Artery Doppler Ratio with Fetal Distress in 38-40 Weeks of Gestation

BACKGROUND AND OBJECTIVE

Knowing the factors affecting fetal distress is of particular importance in improving prognosis in newborns. The study aimed to determine the relationship between fetal middle cerebral artery pulsatility indexes and umbilical artery Doppler ratio with fetal distress at 38-40 weeks of gestation.

MATERIALS AND METHODS

In this prospective cohort, 181 consecutive pregnant women with 38-40 weeks of gestational age were selected by a non-random convenience sampling method from January 2016 to January 2017. Women with labor pain and embryos with chromosomal and structural disorder were excluded. Color Doppler sonography was done for all of them, and the association of this ratio with fetal distress consequently was assessed as well.

RESULTS

In this study, abnormal amniotic fluid index (AFI) (1.1%), low birth weight (< 2500 g) (5.5%), emergency cesarean (11.6%), neonatal intensive care unit (NICU) admission (12.2%), low 5th minute Apgar (< 7) (0.6%), abnormal fetal monitoring (10.5%), fetal distress (11.6%), meconium aspiration syndrome (10.5%), and respiratory distress (3.9%) were present. The mean cerebroplacental ratio was 1.9. There was a significant association between low fetal middle cerebral artery pulsatility index and umbilical artery Doppler ratio with fetal distress, abnormal monitoring, and urgent cesarean (P = 0.006). The cutoff 1.94 led to sensitivity, specificity, positive predictive value, and negative predictive value of 80.95, 50, 17.5, and 95.2%, respectively.

CONCLUSION

It may be concluded that in our study a cutoff for fetal middle cerebral artery to umbilical artery ratio of 1.94 at 38 weeks was considered statistically significant in predicting fetal distress at 38-40 weeks. However, further studies with larger sample size and multi-center sampling would develop more definite results for wider application.

Sonographic Estimation of Amniotic Fluid Volume Using the Amniotic Fluid Index and the Single Deepest Pocket in a Resource-Limited Setting

Objective

To determine the normal value of amniotic fluid (AF) volume among pregnant women in a Northern Nigerian population and to determine if there is a relationship between AF index (AFI) and single deepest pocket (SDP) with anthropometric variables.

Materials and Methods

A prospective cross-sectional study was conducted among singleton pregnant women at late second and third trimester attending the antenatal clinic in Abubakar Tafawa Balewa Teaching Hospital, Bauchi, from December 2016 to April 2017. The mean AFI and SDP were measured by sonography. Ethical approval was obtained from the institution and informed consent was sought for from all the participants. Descriptive statistics, i.e. mean, standard deviation, and correlation coefficient, were used for the analysis.

Results

A total of 206 women, aged between 18 and 40 years, with fetal gestational ages between 22 and 39 weeks were included in the study. The values for AFI in the study ranged from 12 to 28.7 cm, with a mean value of 19.84 ± 3.64 cm, and SDP ranged from 3.7 to 9.1 cm with a mean value of 6.04 ± 1.12 cm. This study found a weak relationship between the anthropometric variables and AFI and SDP and a strong relationship between AFI and SDP with a correlation coefficient of R = 0.901 and P = 0.014.

Conclusion

This study found the mean values for AF volume using AFI and SDP in the studied population to be 19.84 ± 3.64 cm and 6.04 ± 1.12 cm, respectively; a strong positive relationship between AFI and SDP; and a negative relationship between body mass index with AFI and SDP.

The Influence of Fasting in Summer on Amniotic Fluid During Pregnancy

Objectives:

Ramadan is a holy month in which eating and drinking are forbidden from dawn to sunset. In this study, we investigated using ultrasonography (USG) whether fasting in summer (as occurred in Ramadan 2014) had an influence on the volume of amniotic fluid during pregnancy.

Materials and Methods:

The study included 119 pregnant women in total who were admitted to our department with a request of obstetric USG between June 28, 2014, and July 27, 2014. The fasting group included 61 pregnant women and the control group of 58 pregnant women. In our study, all the fasting pregnant women had Sahur (predawn meal eaten before starting fasting) and Iftar (the evening meal for fast-breaking) every day, regularly. The women in the control group did not fast. In addition to amniotic fluid index and fetal biometric measurements during Ramadan, amniotic fluid volume was measured ultrasonographically throughout pregnancy. All ultrasound examinations were performed at least 8 h after Sahur during Ramadan. Chi-square test was utilized to compare the measurements of amniotic fluid volume, and Mann–Whitney U-test was utilized to analyze the differences in fetal growth data. Moreover, difference was considered statistically significant when the P value was <0.05.

Results:

The mean age was 25.7 years in the fasting group and 25.8 years in the control group. Other characteristics and mean gestational weeks of the two groups were similar. Ultrasonographically, there was no significant difference between two groups in respect to amniotic fluid amount during pregnancy (P = 0.7). There was no significant difference with regard to fetal growth parameters either (P > 0.05).

Conclusion:

In pregnant women who had regular predawn and fast-breaking meals, fasting in summer did not elicit alteration in the amount of amniotic fluid throughout pregnancy.