Importance of Establishing Estimated Delivery Date

Management of prolonged pregnancy

Naegeles rule

In the process of management of prolonged labour, the first thing is to establish the estimate delivery date (EDD), double check the EDD and confirm which method was used to calculate EDD. With the increase demand of an early ultrasound scan, Naegele’s rule has been used to determine the EDD. Naegeles rule obtained by adding seven days to menstrual period, then counting back three mouths and lastly adding one year to arrive at the expected date of delivery (Walker & Gan, 2017)

EDD is very easy and cost effective, women may be unable to remember the last menstrual period (LMP) or misreport their LMP due to mid cycle bleeding. Women who are younger, primiparous or have low education are more likely to misreport last menstrual period (Deputy et al., 2017) The work of loytved and fleming (2016) examined close the important of EDD, firstly it is very important to obstetric and midwives management , it provides guidance for prenatal test, gauge fetal growth throughout the pregnancy. Secondly plan for management of prenatal complications, preterm labor management and timing for postdate induction of labour. Lastly for pregnant women and partner the EDD is an estimated birthday that families looking forward to gathering and celebrate.

(Smout, Seed, & Shennan, 2012) reported that most of the post term births are believed to come from the inaccurate calculation of gestational age. 12.1% was the figure when EDD was calculated for post-term birth, that obtained after using first day of the LMP. This can be compared with 3.4% results that obtained by the method of ultrasound scanning. (Smout et al., 2012) continue emphasis that the any difference of gestational age no matter how small differences it is, it can bring a huge impact clinically in both mortality and morbidity. In UK gestational age of less than 23 + 0 weeks are not requires resuscitation, this means that any inaccuracy of EDD can have an enormous effect and can make the decisions of clinicians harder.

On other hand (Hunter, 2009) continue to suggest the use of Ultrasound technique to estimate delivery date (EDD). Ultrasound technique is an advanced method on EDD compared to Naegeles rule which based on LMP. However, we must continue to discuss in detail with women and find out how they obtained LMP. By doing so this will help to eliminate the overuse of ultrasound for EDD. The research work of (Butt & Lim, 2019) has been based on the gestational age and has outlined the guidelines created by the physicians which could explain how ultrasound could determine EDD. Gestational age and size of the embryo are crucial regarding the evaluation of EDD during ultrasound, this means that during the first trimester EDD has greater accuracy is more accuracy.

However, Duputy et al (2017) concluded that ultrasound has emerged to be an accurate method of assessing foetal gestational age especially in the first trimester, both transvaginal and trans- abdominal probe assessments are used to obtain a more accurate measurement of gestational age.

Bishop Score

(Gokturk, Cavkaytar, & Danisman, 2015) reported that, Once the EDD confirmed, before the induction of labour, cervical assessment must be performed. Bishop score- Manual vaginal evaluation which suggested > 6 is favourable for labour induction and closed cervix is difficult to assess. Bishop score is widely used to evaluate the cervix and determine the successful delivery. Its sensitivity is 23-64% so it is not a good procedure to use when determining the birth outcomes.

Bishop score is the traditional method of assessing cervix position, consistency, effacement, dilation and station of the foetal presentation part. However, the cephalic presentation is mandatory to this bishop score criteria. Usually, 13 point is the maximum score of bishop score, women who have greater score of 9 or more than, they have shown to have a significant results on induction of labour (Iu, Ac, Gu, & Ce, 2015).

Apart from this, according to (Iu et al., 2015), regarding their review work and comparison with others, they concluded that women who achieved at least six point of bishop score , 90% of women will have vaginal birth within six hours. Meanwhile those women who did not reached six point of bishop score, the mode of delivery was reported to be unpredictable.

Recently the work of (Ivars et al., 2016) reports the use of bishop score successful by simplified it with parity factor. On their work they compared primiparity and multiparous women whereby the results have shown to have big an effect on induction of labour. Multiparous women had shown to have a successful rate on bishop score than primiparity because multiparous women have shown to have a good favourable cervix and hence high bishop score.

More ever, cervical sonographic evaluation has been reported to be more accurate/ sensitive in comparison to bishop score to determine birth outcome. Transvaginal ultrasound process examines cervical length and foetal head position and can determine mostly accurate birth outcome and after completion of the cervix assessment the induction of labour can proceed. Induction of labour is indicated when the benefits of delivery to the mother and foetus outweigh the potential risks of continuing the pregnancy (Ivars et al. 2016).

Timing of Induction – Traditionally, pregnancy can continue up to 42 weeks or more than 42 weeks. However, IOL can commence at 41 weeks instead of waiting for spontaneous events. Women with 41 or 42 weeks of pregnancy can be offered IOL. This is because the IOL around 41 and 42 weeks does reduce perinatal death and a lower incidence of Meconium Aspiration. Moreover, if pregnant women refused IOL at 42 weeks, then, Cardiotocograph and ultrasound for assessment of maximum amniotic fluid must be put in place and should be performed twice a week. However, for low risk pregnancy at 42 weeks, there has not been any increment of stillbirth (Kenny and McCarthy 2013)

Contraindications to induction of labour must be put in place when performing induction of labor and it can be grouped into three categories. Firstly, maternal contraindications which based on regular contractions, unexplained maternal pyrexia, previous caesarean sections if more than two caesarean and active herpes. Secondly, foetal contraindications which include malpresentation, transverse lie, Cardiotocography abnormalities which explain non reassurance of foetal status and cord prolapse. Thirdly and lastly, there are the placental contraindications, on this group of placenta previa, abnormal bleeding and vasa previa are central to this category. All these contradictions directly tend to stop the induction of labour and result in caesarean section procedure for the safety of the mother and baby (Ryan & McCarthy, 2016)

Cook’s balloon

It works by disrupting the integrity of amnion chorion and myometrium interface and cervical collagen stimulating prostaglandin release and rendering the uterus susceptible. Advantages of this method are cost effectiveness, ease of access and application, lack systemic side effects and reversibility of the process and it can be used in women with prior caesarean sections. However, in spite of so many advantages (Hasegawa et al., 2015) observed that the use of Cook’s balloon has been associated with the high risk of umbilical cord prolapse especially when disk types are used and ball balloons are filled with large amount of water (180 – 250mls). Furthermore, Hasegawa et al., (2015) reported that there are some discomforts on insertion of Coock’s balloon.

The discomforts on insertion of cooked balloon have been discussed differently by Xing et al.,( 2019) that the discomfort only happened on single balloon, and this was compared after two groups of women used single balloon and Cook’s balloon. It has observed that, the volume that used in single balloon was larger compared to Cook’s balloon. The large volume in single balloon created more pressure on unripe cervix which increased the pain and more discomfort during the process of IOL, while the cook balloon has reported to have minimal pain score compared with single balloon. Pain score during catheter insertion in double-balloon catheter group was significantly lower than in single-balloon catheter group. Apart from this, the single balloon had high rate of laceration of the cervix and cord prolapse.

Other researchers such as (Du et al., 2015) compared single and cook balloon which have been used for cervical ripening and induction of labor. They concluded that both are effective with the same but he single balloon has significantly showed that it’s more comfortable to women. However, single and cook balloon had less frequent of uterine hyperstimulation than other hormonal mechanisms (Pharmacological agents) such as Dinoprostone and high percentage of vaginal delivery within 24 hours of induction of labor.

Also, mechanical induction such as Cook’s balloon and single balloon, have been reported to be routine methods for induction of labour. One of the raised concerns is that this method could link up with the damage of the cervix and increase the high chance of having preterm birth in a subsequent pregnancy. But the work of (de Vaan et al., 2019) concluded that there is no link which is associated with preterm birth after, women of singleton pregnancy who were at term in cephalic position, took a trial. Mode of induction of labor was either 30c of single balloon or prostaglandin hormone. However, de Vaan et al., (2019) did not explain the effect of Cook’s balloon on their work. This can suggest that in future trials, it would be required to be investigated if Cook’s balloon can cause damage to the cervix and hence, to preterm birth.

Midwife role

Explain the length of time it may take to labour established. Consent issues are just as important and even though a woman has agreed to IOL her consent for Vaginal examination and interventions is required. (NMC 2015)

Documentation clearly to show care plan labour progress and drug used in I OL

Cardiotocography / Foetal rate monitoring and full MEWS must be taken on admission.

Reference

Butt, K., & Lim, K. I. (2019). Guideline No. 388-Determination of Gestational Age by Ultrasound. Journal of Obstetrics and Gynaecology Canada, 41(10), 1497–1507. https://doi.org/10.1016/j.jogc.2019.04.010

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