Prevalence of Nausea and Vomiting of Pregnancy and its Associated Factors at Three Teaching Hospitals in Ethiopia

A hospital based cross-sectional study was done. A structured questionnaire containing modified PUQE 24 score was administered by trained data collectors. SPSS for windows version 23 was used for data analysis and statistical significance was assessed using the odds ratios, 95% confidence intervals, and p values.


Introduction
Every third pregnant women coming for antenatal care or visited the emergency Ob-Gyn departments at St. Paul's Hospital Millennium Medical College and it's two affiliate Hospitals in Addis Ababa, from Monday through Friday, was recruited till the desired sample size was achieved. Data was collected by doing face-to-face interviews and using a structured questionnaire containing modified PUQE 24 score. Data was collected by nurses and midwives.
Pregnancy unique quantification of emesis and nausea scoring index (PUQE) was used to assess severity of emesis which had three questions regarding the time span of nausea, vomiting and retching respectively.

Modified PUQE-24 scoring system
A) On average in a day, how many times have you felt nauseated or sick to your stomach?
No time (1), 1-2 times (2), 3-4 times (3), 5-6 times (4) 7 or more times (5) PUQE-24 Score: Mild = 6; Moderate = 7-12; Severe = 13-15 Data editing was done by principal investigator to ensure consistence and completeness of data. Data was entered into a computer using Epi info 7. Final analysis was done using SPSS for windows version 23. Frequencies and measures of variation was used to describe study outcomes, including socio-demographic characteristics and other relevant variables. Multivariate regression analysis was done for predictor variables. Odds rations, 95% confidence intervals, and p value less than 0.05 was used to describe findings significance.

Results
From 350 pregnant women included in this study, the prevalence of nausea and vomiting of pregnancy was 74.9%. As shown in Table 2, mild nausea and vomiting of pregnancy which is PUQE score ≤ 6 was found to be 26.3%, while moderate nausea and vomiting of pregnancy (PUQE score between 7 and 12) represented 58% of the nausea and vomiting cases. Severe nausea and vomiting of pregnancy (PUQE score between 13-15) was observed in 15.6% cases of nausea and vomiting. The age of study participants ranged from 15-45 years with mean of 28 years, with 46.13% of them being in the age group between 25 -30 years ( Table 2).
In multimodal regression analysis (Table 3), having previous history of nausea and vomiting, multiple order pregnancy and family history of HEG were strongly associated with the occurrence of nausea and vomiting. Twenty-three percent of pregnant women with family history of nausea conditions, and both high and low maternal pre-pregnancy weight [7].
A range of treatment of HEG includes dietary and lifestyle modifications, complementary therapies (i.e. acupuncture), and pharmaceutical therapies including a variety of classes of anti-emetics and corticosteroids, and enteral/parenteral nutrition [7][8][9][10]. No single measure can easily define, quantify or evaluate the severity of nausea and vomiting of pregnancy, but an English pregnancy specific questionnaire PUQE (Pregnancy-Unique Quantification of Emesis) has been developed in order to assess the severity of nausea and vomiting in pregnancy [10].
HEG can cause a potentially life-threatening complication of pregnancy and is potentially lethal if not treated. The etiology and pathogenesis of HEG is unknown. But it is said to be multifactorial and the result of complex interaction of endocrinologic, psychoneurotic, genetic and environmental factors [11]. The aim of this study was to assess the prevalence of NVP and it's associated factors among Ethiopian pregnant women.

Methodology
With objectives of determining prevalence of nausea or vomiting of pregnancy among pregnant women at three teaching hospitals in Addis Ababa and it's associated factors and stratification of the severity of nausea or vomiting of pregnancy using modified PUQE score, a hospital-based cross-sectional study was conducted at St. Paul's Hospital Millennium Medical College (SPHMMC) and it's two affiliate Hospitals in Addis Ababa city.
A single population proportion formula was used with an assumption that was adopted from a previous study that reported a 74.5% prevalence of nausea and vomiting of pregnancy and 6.1% prevalence of severe nausea and vomiting of pregnancy [10]. With a 95% confidence interval, 5% margin of error (d = 0.05), 80% power of study and a 10% expected non-response rate, a total of 355 cases were included in the study, according to inclusion and exclusion criteria.

Inclusion criteria
• Pregnant women who come for prenatal care and who visited emergency gynecologic OPD (EGOPD) at SPHMMC and 2 of its affiliated teaching hospitals in Addis Ababa during the study period and who volunteered to participate in the study.

Exclusion criteria
• Pregnant women who had medical or surgical disorders as a cause of nausea and vomiting.
Ethical approval for the research was obtained from SPHMMC Ethics and Research Committee and a written informed consent was taken from each correspondent before participation in the study and only volunteers who agreed to participate in the study were included. Questionnaires were coded and patients' names was kept anonymous. Privacy and confidentiality was safeguarded throughout the course of the study.

Discussion
Nausea and vomiting in pregnancy (NVP) is an extremely common disorder in pregnancy that ranges in spectrum from mild to moderate nausea and vomiting to pathologic HG [12]. It is estimated that 70-80% of pregnant women experience NVP [13]. In this study, the prevalence of NVP was found to be 74.9% (out of which 15.6 percent were severe NVP). Findings of this study is similar to a previous report of 74.5% from a similar study done in Addis Ababa (Ethiopia) in 2013 [11]. It is however lower than an 88% prevalence reported in a recent study done in Finland [14].
According to a systematic review done in 2013, 70% pregnant women have NVP in pregnancy [1]. Another systemic review and meta-analysis done in the same year, in which 79 studies on NVP from around the world were analyzed, showed that the prevalence of NVP is similarly 70%, (severe NVP representing 14% of the cases) [15]. Our NVP prevalence report is consistent with these two reports and another meta-analysis report that showed 70% of American pregnant women suffer from NVP with 1.2% of them having the severe form of NVP [16].
The finding of 15.6% severe NVP in our study is close to the report of 14% and higher than a report of 8.2% in the Finish study and in a recent study from Southern Ethiopia respectively [17].     [18,19]. In a 2008 study done in California (USA), in which 1225 pregnant were studied, approximately 28% of women reporting a history of HG in their mothers [20]. Our study showed that 23.3% of the women studied had a family history of nausea and vomiting, which is statistically significant ([AOR=5.134 (CI 1.864-14.140)], p-value of 0.002). In another similar study, women without a history of nausea during prior pregnancies were found to have a low risk of developing nausea and vomiting in an index pregnancy [21]. A different study done in 1993 found that approximately two thirds of women who described their vomiting as severe in one pregnancy had similar symptoms in the next pregnancy [22]. In our study, 41% of those who have NVP in index pregnancy had previous history of NVP, which is statistically significant finding (AOR = 2.28 (CI0.057-0.272, p-value of 0.0001).
Multiple pregnancy is listed among the risk factors for NVP [23]. Furthermore hyperemesis gravidarum (HG), the severe form of NVP, occurs more frequently in multiple pregnancies [24]. Multiple gestation was strongly associated with presence of NVP in our study, which is consistent with a report from a study done in Japan in 2018 that showed mothers with twin pregnancies were shown to have higher odds for the presence of NVP and severe NVP. In the study 91,666 pregnant women were analyzed and out of which 75,828 (82.7%) experienced at least some symptoms of NVP (which is higher than our study finding) and 10,159 (11.1%) experienced severe NVP (lower than found in our study) [25]. In our study 12% from those who had NVP were found to be multiple pregnancies, which is again statistically significant (AOR=7.054 CI (1.892-26.309), p-value of 0.004).
Contrary to most reports from different studies, lack of family support, history of previous psychiatric illness and primigravidity were not statistically associated with either presence or severity of NVP in this study. These differences may have arisen from the difference in methodology -some of the studies that found such associations focused on the severest end of spectrum of NVP, which is Hyperemesis Gravidarum, and difference in patient profile included in the study.

Conclusion
The prevalence of NVP in our study was 76.4%, which is similar to the reports from previous studies. Women with personal history of NVP, family history of NVP, and multiple gestation have an increased susceptibility to develop NVP. Identification of such risk factors is important in prepregnancy counselling.

Declarations Ethics approval and consent to participate
Ethics approval was obtained from IRB at SPHMMC and written informed consent was obtained from study participants.