Introduction

Dysmenorrhea considered as one of the most common complaints by women (1) can have undesirable effects on individual and social health status (2). The prevalence of dysmenorrhea has been reported as 25-75%; such difference can be due to the way patients express their complaints to doctors (self-report method) and the manner doctors raise their questions in this respect (3). The prevalence of this disorder in Iran was reported as 71-79% and is taken into account as the main cause of absenteeism from school and work (4, 5).

Dysmenorrhea can be divided into two types of primary and secondary. In this regard, the primary dysmenorrhea refers to the menstrual cramps in absence of any justifiable
pelvic inflammatory diseases. The secondary dysmenorrhea is associated with the occurrence of painful periods due to pelvic pathologic problems (2, 6). In primary dysmenorrhea, no particular problem is seen in female genitals and pain starts simultaneously or a few hours before menstrual bleeding and lasts for a maximum of 2-3 days. Such pains are often observed in menstruations associated with ovulation (1, 7).

The quality of colicky pains or cramps is also diagnosable in the middle and supra-pubic line and sometimes spreads to lower back and groins (2, 8, 9). In addition, primary dysmenorrhea is sometimes associated with problems caused by prostaglandins in peripheral blood, such as nausea, vomiting, diarrhea, and headache (10, 11).

It should be noted that 10-15% of women experience severe symptoms disrupting 1-3 days in their monthly life which are considered as the common causes of absenteeism from work and decrease the quality of life (12, 13). Therefore, the given problem has also led to loss of millions of working hours (14, 15). However, there are several treatments to reduce dysmenorrhea (16, 17).

Numerous studies have been performed on determining the factors associated with dysmenorrhea, including weight, age, number of deliveries, diet, physical activity, smoking, and family history. The published results have inconsistently reported that childbirth can be mentioned among these factors (18, 19, 20, 21). Spiroff and Fritz citing the study by Andresch and Milsom in Sweden argued that women experiencing childbirth could significantly suffer from less severe primary dysmenorrhea than women who had never been pregnant or those who had a history of spontaneous or legal abortion (21).

Moreover, Symonds and Symondsian stated that the primary dysmenorrhea could disappear after birth of the first child (22). Juang and Yen (2006) also concluded that menstrual cramps dicrease in women with preterm childbirth, compared to those with full-term one. Furthermore, women with a history of natural childbirth indicated greater improvements in dysmenorrhea than those undergoing Cesarean section (23).

Firoozi and Zahedifard (2013) conducted a study on the effect of delivery mode on dysmenorrhea severity. According to their results, natural childbirth might lead to greater improvements in pain severity, in comparison
to Caesarean section (24). However, other researchers did not report such a relationship and believed that childbirth has no impact on dysmenorrhea (25, 26). A point in the mentioned studies was that they examined the relationship between pain severity and mode of delivery and ignored the other components associated with pattern of dysmenorrhea. For example Shahri, Soleimani, and Sepandi (2013) as well as Nahidi, Bagheri, and Jansari (2007) investigated pain severity due to dysmenorrhea and mode of delivery (27, 28).

According to the Onset, Location, Duration, Characteristics, Aggravating Factors, Relieving Factors, Treatment (OLDCART) model as a pain assessment tool, several aspects other than pain severity, namely duration, location, quality, and pain symptoms should be considered. On the other hand, studies carried out on the impact of childbirth on the patterns of primary dysmenorrhea do not have similar results in Iran and the reference books of obstetrics and gynecology do not clearly illuminate the changes in this pattern. Consequently, the purpose of this study was to compare the patterns of primary dysmenorrhea before and after childbirth in women who referred to healthcare centers of Mashhad, Iran in 2010-2011.

Materials and Methods

This descriptive-analytic study on 124 mothers compared the pattern of primary dysmenorrhea before and after childbirth. The participants aged 18-35 years with children of 6-36 months old and had a history of delivery whether vaginal or Cesarean section. They had passed at least 6 cycles of postpartum menstruation onset and had also experienced a history of pre-pregnancy dysmenorrhea based on the verbal multidimensional scoring system for assessment of dysmenorrhea severity. Moreover, they did not have history of taking hormonal contraception methods or intrauterine device (IUD) before and after childbirth and did not suffer from postpartum secondary dysmenorrhea.

The exclusion criteria included pregnancy during the study period, changes in contraception methods, and unwillingness to continue participation in the research. The multistage sampling method was similarly conducted on the community healthcare centers numbers one, two, and three in Mashhad. Proportional to the number of centers and patients of each center, the number of mothers was selected using the purposive sampling method according to the statistics from maternal care clinics.

That is, the names and contact numbers of people with a history of one delivery and with children aged up to 36 months who had used interruptive contraceptive method or condom were primarily extracted from the maternal care clinics. Next, these mothers were asked about the status of primary dysmenorrhea before pregnancy at an appropriate time via phone calls. The individuals whose responses were positive and were eligible to be included in the study at the time of interview were invited to participate in the study.

In order to follow the ethical considerations, the research objectives were explained to the participants and informed consents were obtained during a meeting at the healthcare centers. Afterwards, anonymous questionnaires were delivered to collect the data. The questionnaire included maternal demographic data, as well as information regarding delivery and lactation. In addition, the pre- and post-partum menstruation data for three consecutive months after entering the study, as well as a multidimensional scoring system for assessment of dysmenorrhea severity were completed.

Next, the pattern of primary dysmenorrhea was examined through raising five questions on pain duration, severity, quality, location, and symptoms associated with pain in the section related to menstrual information. Pain severity was also determined using the multidimensional scoring system for assessment of dysmenorrhea severity. The validity and reliability of the personal, childbirth, lactation, and menstrual information questionnaire were determined using content validity and internal consistency with Cronbach’s alpha coefficient (α=0.79), respectively.

The multidimensional scoring system for assessment of dysmenorrhea severity used for determining primary dysmenorrhea was a standard instrument whose validity was confirmed by Andresch and Milsom (1982). It had been administered by Torshizi, Golmakani, Saadatjoo, and Rakhshandeh (2006) (29, 18) and the reliability had been confirmed by equivalent forms (r=0.92). According to the pilot study for comparing the ratios before and after childbirth with the confidence level of 95% and the test power of 80%, the sample size was determined as 124 individuals according to a study performed by Juang and Yen (2006).

It should be noted that the data from 144 participants were collected at first but a total number of 124 individuals were recruited because some mothers did not answer the phone calls or menstrual information were not recorded by mothers during follow-ups. Therefore, there was a drop out of 20 individuals. Following recording, the data were analyzed by paired Wilcoxon signed-rank and Cohen’s kappa tests using SPSS version11.5. Furthermore, P < 0.05 was considered as significant in all tests.

Results

The data from 124 study subjects were analyzed. The pattern of primary dysmenorrhea regarding the components of pain severity, duration, quality, location, and symptoms associated with dysmenorrhea (five features of pain severity on the OLDCART) were evaluated before and after childbirth.

Moreover, we investigated the participants in terms of some variables, such as age (25.2±3.57 years), age at first menstruation (13.6±1.54 years), age at marriage (19.6±3.1 years), age of their children (22.6±8.06 months), menstruation onset, and postpartum menstruation (5.05±4.17 months), as well as the breastfeeding duration (8.1±5.61 months).

According to the findings of present study, 80.6% of the subjects suffered from dysmenorrhea grade 2 and 3 prior to childbirth (based on the multidimensional scoring system for assessment of dysmenorrhea severity). This value reduced to 20.9, 22.5, and 28.1% after delivery in the first, second, and third reports, respectively. concerning the results of paired Wilcoxon signed-rank test, the dysmenorrhea severity significantly decreased after childbirth, compared to before birth (P₁<0.001, P₂<0.001, and P₃<0.001) (Table 1).

Furthermore, the results demonstrated that dysmenorrhea duration descended from 24.57 hours before childbirth to 14.83, 14.61, and 14.95 hours in the first, second, and third reports after birth, respectively. The difference in the duration of painful periods was also significant between the three reports given after childbirth, in comparison to before childbirth (P₁<0.001, P₂<0.001, and P₃<0.001).   

Considering the dysmenorrhea quality, the findings revealed a change in the most prevalent type of pain from colicky state before childbirth to obscure, colicky, and colicky states in the first, second, and third reports, respectively (Table 2).

Given the dysmenorrhea location, the findings suggested that the location of pain mainly altered from the lower abdomen to the thighs to the lower abdomen after childbirth as observed in the three reports (Table 3).

Furthermore, we found a significant diminish in the frequency of symptoms associated with dysmenorrhea after childbirth, compared to before it. As a result, 76.6% of individuals reported more than one pain symptom before childbirth, while this value declined with a significant difference to 44.4, 43.8, and 42.5% in the first, second, and third reports after childbirth, respectively (P₁<0.001, P₂<0.001, P₃<0.001). It should be noted that the most common complaint associated with dysmenorrhea before and after childbirth was nausea.

Discussion