Oral Health Related Quality of Life during Pregnancy and Postpartum: A systematic review

The impact of diseases on psychosocial well-being or the normal function of a person has been commonly defined as health-related quality of life .High prevalence of Dental and periodontal problems during gestation period may have a negative effect on oral-health-related quality of life (OHRQoL) in pregnant and postpartum women. This systematic review aims to perform a quality assessment and to give a critical overview of the current research available on OHRQoL in pregnant and post-partum women. Abstract BACKGROUND: The impact of diseases on psychosocial well-being or the normal function of a person has been commonly defined as health-related quality of life .High prevalence of Dental and periodontal problems during gestation period may have a negative effect on oral-health-related quality of life (OHRQoL) in pregnant and postpartum women. OBJECTIVE: This systematic review aims to perform a quality assessment and to give a critical overview of the current research available on OHRQoL in pregnant and post-partum women. The main conclusion of this review is that the presence of signs and symptoms of dental and gingival disease negatively affects the self-perception of OHRQoL in pregnant women. The most affected domains of OHRQoL in pregnant women were related to mental and psychological discomfort followed by physical and functional problems. Considering that the available evidence is limited to cross-sectional design, longitudinal studies are needed to investigate the impacts of oral health status during pregnancy. Our objective was to perform a quality assessment and to give a critical overview of the current research available on OHRQoL in pregnant and post-partum women.in this paper we also review and explain all the instruments and questionnaires employed for assessing OHRQoL up to now. Among many instruments, three of them have been used for measuring OHRQoL in pregnant women up to now. It should be noticed that none of these questionnaires are specifically designed and developed for pregnant women. The major conclusion of this review is that the presence of signs and symptoms of dental and gingival disease negatively affects the self-perception of OHRQoL in pregnant women.

Pregnancy is a period which some changes occur in physical and emotional status of women's health. These alterations lead to notable changes in the oral environment and cause some painful clinical signs and symptoms.
Feeling pain in oral cavity, bleeding and redness of gums and also changes in sensation of taste are the common problems reported by pregnant women. It is conceivable that these symptoms may impair the perceptions of oral condition and Oral Health Related Quality of Life (OHRQoL). Despite the existence of many studies regarding the objective assessment of oral health status in pregnant women, there is no consensus report regarding the status of OHRQoL in pregnant women. This is the first systematic review concerning OHRQoL in pregnant and post-partum women. It takes into account the quality of studies and the 5 most affected domains of OHRQoL in pregnant women.
Our objective was to perform a quality assessment and to give a critical overview of the current research available on OHRQoL in pregnant and post-partum women.in this paper we also review and explain all the instruments and questionnaires employed for assessing OHRQoL up to now. Among many instruments, three of them have been used for measuring OHRQoL in pregnant women up to now. It should be noticed that none of these questionnaires are specifically designed and developed for pregnant women.
The major conclusion of this review is that the presence of signs and symptoms of dental and gingival disease negatively affects the self-perception of OHRQoL in pregnant women.

Introduction
During the period of pregnancy the body undergoes some important hormonal and physiological changes which could be associated to some alteration in oral health status( 1 ). Moreover the alteration in physical and emotional demands of a pregnant woman might contribute to the neglect in oral hygiene behaviors and develop some problems (   2  ,   3 ). Dental caries, pregnancy epulis, Gingivitis and periodontal disease are the most common problems that pregnant women face ( 4-6 ).
The main etiological factor of dental caries and periodontal disease is the ecology or the bacterial flora of dental plaque. During pregnancy, the immunological and vascular changes due to alteration in endogenous steroid hormones, amplify the inflammatory response in presence of dental plaque and calculus( 7 , 6 8 ). Poor oral hygiene cumulated with systemic changes in the body of pregnant women may lead to high prevalence of dental caries and periodontal disease in gestation period ( 9-11 ).
Dental and periodontal problems during pregnancy are not usually fatal, even so feeling pain or discomfort in oral cavity, functional limitations, smiling and social relationships due to teeth appearance or soft tissue problems tend to have a substantial effect on individual wellbeing (   12 ).
The impact of diseases on psychosocial well-being or the normal function of a person has been commonly defined as health-related quality of life ( 13 , 14 ). High prevalence of oral diseases may have a negative effect on oral-health- These databases were searched using the following strategy and keywords: ("quality of life ") AND ("oral health" OR "Dental Caries" OR "Periodontal Diseases" OR " Gingival Diseases " OR " Odontalgia " OR " Pain ") AND ("Pregnancy" OR "Pregnant" OR "Postpartum").This search was not restricted by date or language. In addition, the proceedings of several scientific meetings were hand-checked and the reference lists of all selected articles were also reviewed for potentially relevant studies.

Study selection
Citations found through systematic search were inserted to a Microsoft Excel Software 2010 (Microsoft, Redmond, WA). Titles and abstracts were reviewed by two reviewers (OF and ZSM), independently. After the abstract selection, full-text copies of the selected papers were retrieved and the final selection for inclusion was made. After both reviewers performed the complete selection procedure, the results of the searches were compared and discussed in case of disagreement.

Eligibility criteria
For this systemic review all original and peer-reviewed human studies which investigated 8 OHRQoL of women during pregnancy or post-partum period were searched. For the selection of studies, predefined criteria were used.
All English-written studies providing quantitative information about the status of OHRQoL in pregnant women assessed by a validated questionnaire were included. All the case reports, Letters to the editors, conference proceedings, unpublished studies, narrative reviews and duplicate articles were excluded. When multiple papers were identified on the same population, the study with more information on the data was included in the present review. Studies using general (health related) quality of life measures were excluded. Our search strategy was not restricted to the publication date. Hence all the related evidence up to December 2018 which met the inclusion criteria was assessed. In Fig.1, the flowchart of the study selection is presented. Regarding the OHRQOL measure, the mean and standard deviations of OHRQOL as well as the number of subjects per subgroups were extracted. Meta-analysis was not possible.
Thus, the data from the studies were evaluated qualitatively.
Methodological quality assessment: Methodological quality was assessed using modified items recommended by the Newcastle-Ottawa Scale for observational studies( 9 17 , 18 ). As cross-sectional studies were included in this systematic review, a modified version of the cohort and case-control study scales was employed (Appendix 1). The following items were measure for each study: representativeness of the sample (evaluated by the sample generation methods and sample origin, e.g., community, specific population groups); comparability (evaluated by the presence of a control group); outcome (outcome assessment tool; concealment for evaluation of outcome; adjustment for confounders and non-response rate). A percentage score was established for each study in accordance with the number of items present (Appendix 1).

Results
Tables 1 and 2 describe the methodology and main findings of the studies. All the included studies had cross-sectional design regarding to assess OHRQoL in pregnant woman. The most frequent number of studies were conducted in Brazil (N=3) followed by India (N=2), China (N=1), Argentina (N=1) and Uganda (N=1). Based on the inclusion criteria, there was not any paper from European or Oceania countries related to our PICO   In the other four studies, the most affected domains were reported based on the OHIP questionnaires. The domains entitled by "Physical pain" and "Psychological discomfort "were grouped as the most affected sections of questionnaires in all 4 studies. Besides these domains, the other domains most affected in pregnant women were "Functional limitation" (3/4 studies), "Physical disability" (2/4 studies) and "Psychological disability" (2/4 studies).
Association of OHRQoL scores with clinical and self-reported parameters: With the aim of analyzing the association of OHRQOL with other evidences of oral cavity problems based on the results of included studies, we sorted the disease parameters in two groups of "self-reported items" and "clinical parameters".
Of the 8 studies included in this review, 4 of them employed self-reported items to gathering data related to oral health status of participants. Based on the association analysis of the papers, all of self-reported items except one (self-reported number of teeth) were associated with OHRQoL scores ( Table 2). First, the exposures were evaluated according to different subjective and objective indices. For the periodontal condition, for example, More than 6 different parameters were adopted in different studies, and the case definitions of tooth loss and dental pain were also distinct. In this regard, collecting a pooled estimate for such different parameters is unlikely to provide useful information from a theoretical and clinical perspective.
In addition, the outcome was evaluated by various OHRQoL questionnaires, which were validated in different ways. Finally, in various studies, the investigations were performed among the women with different socioeconomic status and cultural influences.
It should be considered that our main question was looking for the overall status of OHRQoL among pregnant women; therefore all the included articles were cross-sectional studies. It is obvious that the sampling method of a cross-sectional study cannot be random and it should be considered as a limitation. Moreover, Majority of the studies 14 didn't perform adjusted analyses and there was no uniformity among the confounding factors and the way they were collected (Table.1). This can introduce bias to our results since factors such as age, parity and the period of pregnancy and also the socioeconomic status of women could confound the associations between OHRQoL and oral conditions.
According to the results of this systematic review, there is no conditioned-Specific instrument for measuring oral health related quality of life in pregnant women. In the absence of validated instruments specific to pregnant and postpartum women, all the researchers evaluating OHRQoL in pregnant women use generic instruments. Generic OHRQoL instruments are broad measurement scales, such as OHIP-14 and OIDP that measure OHRQoL in general population. While such questionnaires may be reliable, they may not be appropriate to evaluate OHRQoL in special populations, like pregnant women.
They may not be sensitive enough to detect small but important impacts of oral health status during pregnancy. It is obvious that the oral health status of women undergoes some important changes during pregnancy which is the result of physiological and behavioral alteration during the gestation period. Consequently, developing an instrument for measuring OHRQoL specifically in pregnant women might be beneficial and useful for future investigations.

Conclusion
The main conclusion of this review is that the presence of signs and symptoms of dental and gingival disease negatively affects the self-perception of OHRQoL in pregnant women.
The most affected domains of OHRQoL in pregnant women were related to mental and psychological discomfort followed by physical and functional problems. Given that the available evidence is limited to cross-sectional designs, longitudinal studies are needed to investigate the impacts of oral health status during pregnancy and improve the existing evidence on the importance of other parameters such as age, parity, period of pregnancy 15 and socioeconomic status. Availability of data and materials: The datasets analyzed during the current study are available based on the request.

Competing interests:
The authors declare that they have no conflict of interest.

Availability of data and materials
The dataset supporting the conclusions of this article available and will be presented 16 based on request.