Assessing the Accuracy of Delivery Date Estimation in Rural Panama

INTRO: Although the maternal and infant mortality rates in Panama are reported as being within the best of the Latin American countries, there is a sharp contrast between the rates reported in urban and rural populations.... [ view full abstract ]

INTRO:

Although the maternal and infant mortality rates in Panama are reported as being within the best of the Latin American countries, there is a sharp contrast between the rates reported in urban and rural populations. According to the United Nations Population Fund (UNFPA), the maternal death rate in Panama averages 70 deaths per 100,000 live births; however, the death rate in indigenous populations, like the Ngöbe and Naso, is reported as reaching as high as 658 per 100,000 live births [1]. Extreme poverty, lack of transportation, and cultural practices and attitudes contribute to this stark difference between maternal mortality rates in Panama. This dichotomy is also found in infant mortality rates in urban versus rural Panama: the infant mortality rate in Bocas del Toro (a region primarily populated by these indigenous groups) is reported as being three times that of the country as a whole [2].

It is common for Ngöbe pregnant women to go into labor with only the company of a local midwife (partera), and many of these women live hours or days away from a hospital. Due to these barriers, Ngöbe pregnant women rarely travel the long distance to see a physician for prenatal visits or delivery. For the most part, populations of Bocas del Toro currently use last menstrual period (LMP) to predict delivery date. However, given the lack of prenatal care in the region, it is currently unknown if they are using LMP correctly to date their pregnancies.

The purpose of this study is to compare standard dating criteria of the Ngöbe population with best practices of dating established by the American College of Obstetrics and Gynecology [3] using LMP and ultrasound. It is important that this prediction is accurate given geographical, transportation, and financial barriers that the Ngöbe must overcome to travel to the mainland for delivery. The primary goal of this study is to quantify the difference between ultrasound and LMP dating results in this population, while the secondary goal is to review medical charts for actual delivery dates of women scanned in previous years and compare this to their estimated delivery dates.


METHODS:

This study is conducted in Bocas del Toro, Panama by a group of medical students partnering with Floating Doctors, a non-profit organization that provides medical care to the Ngöbe population. Pregnant women presenting to the Floating Doctors clinic are scanned using ultrasound according to the Rural Obstetric Ultrasound Triage Exam (ROUTE) protocol. Gestational age is measured using crown rump length (CRL) for pregnancies in the first trimester and biparietal diameter (BPD) for pregnancies in the second and third trimester. This data may then be compared with the gestational age calculated from patients’ self reported LMP using the first day of full flow during their last menstrual period as the specific date.

RESULTS:

Data collection for this study is currently on-going and is scheduled to continue until July 2016. Preliminary data from prior teams performing the ROUTE protocol and the same study design shows that, on average LMP and ultrasound measurement estimates of gestational age differ by 19.79 days (n = 99). Upon completion of the study, further analysis will be performed with a larger sample size.

CONCLUSION:

Initial findings reveal a discordance between gestational age calculated by LMP and ultrasound dating in the Ngöbe population. With continued data collection we expect to see a similar trend and with further analysis of this data we will determine the accuracy of these dating methods. If there proves to be a significant difference in accuracy of dating methods, this should be further investigated as there are many potential factors that could affect dating, such as inaccurately reported LMP and factors that affect the rate of fetal development. Having the ability to accurately and easily determine gestational age and estimated delivery date for the women of the Ngöbe tribe is important for providing these women the opportunity to have more planning and resources available to them at the time of their delivery and could potentially help to improve maternal and infant mortality rates in this population.