Prematurity prevention – Self-Care-Program for pregnant women

Prof. Erich Saling MD FRCOG, Jürgen Lüthje MD, Monika Schreiber MD

pH measurement
Warning signs






In order to detect a risk of prematurity as early as possible, in 1993 we added a supporting new concept to our Prematurity-Prevention-Program, which is based on the active co-operation of the pregnant woman herself: the so called “Self-Care-Program for pregnant women” [Saling et al. 1995a and 1995b].

The main points of the Self-Care-Program are:

  • information about risk factors
  • pH self-measurement at regular intervals
  • self observation of warning signs

We recommend all pregnant women to participate as early as possible in the Self-Care-Program, ideally beginning just after pregnancy has been diagnosed.

Information about risk factors

Our information brochure informs the pregnant women about anamnestic risk factors and particular conditions in the current pregnancy.

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pH self-measurement

Every pregnant woman is recommended to measure the pH value in her vagina twice a week herself, by using a special indicator. It can be used in the form of test paper by itself (“Spezialindikator pH 4.0–7.0”; art-no. 1.09542 by Merck, Darmstadt/Germany), but in cooperation with us special disposable gloves have been developed, with a piece of test paper fixed on the tip of the index finger (CarePlan VpH, made by Inverness Medical). The majority of the women that we consulted, reported that it is more comfortable to use the gloves, rather than just to use the test paper.

The woman simply introduces the index finger into her vagina, withdraws it shortly afterwards, and compares the color of the indicator paper with the enclosed special color scale, in order to read the pH value (see fig. 1). When pH values are increased to 4.7 or higher, the patient should see her practitioner at once.

If her doctor confirms the reduced acidification, additional examinations should be performed, in order to find the cause of the acidity disturbance. The consequent procedure depends on the stage of threatened prematurity (see “Prematurity-Prevention-Program”).

pH-measurement: comparison with
          the color scale

Fig. 1: pH-measurement: comparison with the color scale

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Self observation of warning signs

Independent of the vaginal pH self-measurement, all expectant mothers should be made aware of the most important warning signs. They are listed in the information brochure (see Table 5). If anything unusual happens, the patient should see her doctor.

Table 1: Warning signs of a threatened preterm birth (part of the patients brochure)

The patients are advised to get in touch with their doctor as soon as possible if any of these signs are present.

  • repeated measurement (with the test glove) of a vaginal pH value of 4.7 or higher.
    Attention: Particularly high values may be due to the loss of amniotic fluid (premature rupture of the membranes).
  • vaginal bleeding or spotting
  • bad smelling or highly increased discharge (a slight increase is normal during pregnancy)
  • abnormally frequent urination (a slight increase is also normal) or a burning sensation when urinating
  • itching or burning in the intimate region
  • fever and/or diarrhea (these conditions are often associated with an increase in uterine activities)
  • preterm contractions:
  • considerable pains similar to menstruation
  • aching in the groin or in the sacral region
  • temporary, repeated hardening of the uterus

Preterm contractions should be regarded as critical, if they occur more than twice per hour, or more than 10 times during the whole day.

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Benefits of the self-care program

As the program is fundamentally based on a screening-principle, as many patients as possible should be motivated to take part, at best, every pregnant woman without exception. The reason for such a recommendation is that, during the course of even supposedly normal pregnancies, late abortions and preterm delivery can occur. It is very probable that a large number of these patients will have had early symptoms that could have been detected but which remained concealed.

The self-examination should be started very early on to detect the threat of irregularities in good time, that is at the earliest possible moment in the pregnancy. In cases with a poor history, it would be even better to choose a preconceptional moment, that is weeks or months before a planned pregnancy. For some women it could be really important to detect potential risks themselves at such an early stage and to inform their practitioner even before the pregnancy has started or at the latest very early on in the pregnancy.

Hübner confirmed the importance of early onset of pH self-measurement in pregnancy. She evaluated questionnaires from 607 pregnant women, who participated in the “Thuringia prematurity prevention campaign 2000” (see results) (Hübner [published in Hoyme & Saling 2004b])

Among women who started measurement before 15+0 gw, the total rate of preterm births was 4.8 %, and the rate of very preterm births was 0 %. In contrast, when women started pH-measurement at 15+0 gw or later, there were 6.1 % preterm births, and 0.9 % very preterm births.

The main advantage achieved by the patient’s active participation is, that increases in vaginal pH or the manifestation of any other risk factors are identified very early, and this leads to the detection of a considerable number of disturbances connected with spontaneous abortions and preterm births. This enables the practitioner to avoid longer, critical latency periods, sometimes of several weeks. In particular, without these new facilities, some symptoms remain concealed although they are, in fact, easily recognizable. Furthermore, there is also a possibility of controlling the behaviour of vaginal acidity at short intervals, for instance to follow effects of therapeutic measures.

Hübner (published in Hoyme & Saling 2004b) also confirmed, that it is important to measure regularly at short intervals. Among patients who did not only start the pH-measurement early in pregnancy, but also – according to our recommendations – measured twice a week, the total rate of preterm births was 4.2 %, and the rate of very preterm births was 0 %. In contrast, in the group of women who started pH-measurement at 15+0 gw or later, or measured less frequently than twice a week, there were 7.3 % preterm births, and 0.8 % very preterm births. However, the differences between these rates are not statistically significant.

Now and then, some colleagues claim that self-measurement of vaginal pH would have no other effect than making the pregnant women uncertain. The opposite is true. In an inquiry we asked the women who participated in our prenatal-care self-examination program regarding this point. The vast majority answered that they found it very good, reassuring, and had a good feeling about it etc., because they were able to do something themselves [further details: Saling et al. 1995a]. Even if it might sound surprising to someone: Just because of these simple regular self-examinations, most of the users have the feeling, not to be a “treated object” during pregnancy anymore, but to become an “active subject”.

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Results of self-examination

The results evaluated up to now appear to justify the pH self-measurement by pregnant patients and demonstrate the efficiency of our Self-Care-Program. The results have already been published in detail e. g. [Saling et al. 1995 a, Saling 1995 b, Saling et al. 1999, Saling et al. 2001], here just the main figures:

In a study by our department [Riedewald et al. 1992] of 100 women who had measured their vaginal pH themselves using indicator paper, 91 % of the measurements corresponded with the results later measured by a physician with a pH-meter. In 9 % of cases, the results were false-positive; this means that with the indicator paper an increased pH value was measured, but the value controlled by pH-meter was normal. This is not a grave error as there were no false-negative results, i.e. no pathological findings were overlooked.

Furthermore, we found that in about 70 % of the patients who had increased pH values measured both by indicator paper and by the pH-meter, evidence of pathogenous organisms was found in the vagina and/or the cervix, whereas when the pH values were normal, the figure was only 8 %.

The full Self-Care-Program was started in September 1993. The program was advertised in publications that are frequently read by pregnant women.

To date, about 10000 pregnant patients have participated or are still participating, and about 3000 returned the questionnaire to us. Of the 1715 women whose data have been evaluated so far, 595 were pregnant for the first time and 1120 had been pregnant before. The anamnestic information given by the group of women with previous pregnancies was particularly interesting (see figure 2). A high number of these women, namely 46.4 %, had had miscarriages and about 18.3 % had had underweight infants (< 2500 g) during the immediate previous pregnancies. To date, we are able to draw the conclusion that the participating women belong to a higher-risk group rather than to a lower-risk group. According to the returned records, 60.8 % of the patients reported ‘disturbed courses’ in their present pregnancy.

Bar chart showing rates of low birthweight infants
              before and after prenatal care self-examination

Fig. 2: Rates of low birth weight infants before and after prenatal care self-examination

Please click on the miniature picture.

Our evaluations have shown, that the rate of underweight infants, in particular the very small ones (birth weight < 1500 g) in all pregnant patients who took part in this program, is clearly lower at 1.3 % than in previous pregnancies, when the rate was 7.8 %. The rate of extremely small infants (< 1000 g) is 0.9 % when the women participated in our program, compared with 3.9 % in previous pregnancies.

Another evaluation shows comparisons between the results of the immediate previous pregnancies and the present pregnancies only of those women who had suffered a preterm birth in the immediate previous pregnancy. Of the 111 women, only 20 (18 %) again gave birth to a preterm baby (< 37+0 weeks of gestation). Of the 38 women who had given birth to a very preterm baby (< 32+0 weeks) in the immediate previous pregnancy, only 3 (8 %) suffered the same misfortune again, and, of the 22 who had given birth to an extremely preterm baby (< 28+0 weeks of gestation), no recurrence happened.

Results of the Erfurt and of the Thuringian prevention project 2000

The effectiveness of our self-care program was also proved by two prospective campaigns [Hoyme et al. 1998, Hoyme et al. 2002, Hoyme & Saling 2004]. The first was carried out in Erfurt (the capital of Thuringia, Germany), where pregnant women have been offered to perform self-measurements of their vaginal pH by means of test gloves. Patients who were not interested in participating served as a control group. In this study, the prematurity rate was 8.1 % in the self-measurement/intervention group versus 12.3 % in the control group. 0.3 % versus 3.3 % of the neonates belonged to the group of very preterm babies with a gestational age of < 32+0. PROM was registered in 22.8 % versus 30.8 %, respectively.

Encouraged by these results, in 2000 a similar pH screening campaign was initiated in the whole state of Thuringia, in order to reduce preterm births. The goal was to compare data from babies who were born in the first half-year of 2000 (where no participation in prenatal care self-examination was offered to the pregnant women) with data from babies who were born in the second half-year of 2000 (where participation in prenatal care self-examination was recommernded to the pregnant women).

The figures in the state Thuringia were obtained from the official Thuringia Perinatal Inquiry and included data of about 16 000 women. In the half year with the program a significant reduction of very preterm births from 1.58 % to 0.99 % (see figure 3), and regarding low birth weights a significant reduction of cases in all groups was achieved (see figure 4). Concerning pregnancies with twins and triplets, which are at especially high risk, there was also a considerable reduction of preterm births (see figure 5).

Bar chart showing rates of very early
              prematures and of all prematures in Thuringia 2000

Fig. 3: Thuringian prematurity prevention project 2000

Rates of very early prematures and of all prematures
Hoyme et al. (2002).

Please click on the miniature picture.

Bar chart showing rates of children with
              extreme low and very low birthweight in Thuringia 2000

Fig. 4: Thuringian prematurity prevention project 2000

Rates of children with extreme low and
very low birth weight
Hoyme et al. (2002).

Please click on the miniature picture.

Bar chart showing birth weights of prematurely
              born twins and triplets in Thuringia 2000

Fig. 5: Thuringian prematurity prevention project 2000

Birth weights of prematurely born twins and triplets
Hoyme et al. (2005).

Please click on the miniature picture.

When interpreting the figures, it should be considered that only about 50 % of the women who were pregnant in Thuringia in the second half-year of 2000 had participated in the prenatal care self-examination. That means, if all Thuringian pregnant women would have participated, the results very probably had been even better.

After the campaign in Thuringia had been finished, the prematurity rates monitored in 2002 were as high as they had been prior to the introduction of the activities. That’s why a new Thuringia prematurity prevention campaign 2004/2005 started on September 1st 2004.

Some German health insurance companies offer our prenatal-care self-examination program as a pilot project to their pregnant members at no charge. This is especially important, because prematurity is most frequent in women with low social status. The companies started this project in December 2003, and after first internal evaluations, they have already saved a high amount of expenses.

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Currently our Prematurity prevention program, particularly with its self-care activities – as has been confirmed by our evaluation and afterwards by two campaigns by Hoyme and co-workers – seems to be the most efficient, easily applicable and inexpensive program for prevention of very preterm births. Thus it has high importance in the field of health and social care, and has considerable value within our social community.

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  Literature about prematurity and prematurity prevention