PRENATAL DIAGNOSISPrenat Diagn 2011; 31: 985–989.Published online 3 August 2011 in Wiley Online Library(wileyonlinelibrary.com) DOI: 10.1002/pd.2820

Direct access midwifery booking for prenatal careand its role in Down syndrome screening

Tariq S. Nawaz1, Gillian M. Tringham1, Stephen Holding2, Jane McFarlane3 and Stephen W. Lindow4*1Hull York Medical School, University of Hull, Kingston upon Hull, UK2Department of Clinical Biochemistry, Hull Royal Infirmary, Kingston upon Hull, UK3Public Health Team, Women and Children’s Hospital, Hull Royal Infirmary, Hull, UK4Academic Department of Obstetrics and Gynaecology, Women and Children’s Hospital, Hull Royal Infirmary, Hull, UK

Objective To compare the uptake of Down syndrome screening by women following referral by direct accessand general practitioner (GP) modes.

Methods The method of referral by either GP or direct access, for women who booked into prenatal care inHull and East Yorkshire in 2010, was analysed using data collected from the Protos database at the Women andChildren’s Hospital, Hull. Subsequently, the uptake of first and second trimester screening for Down syndromewas reviewed by combining the Protos database to the screening data collected by the Clinical BiochemistryLaboratory at Hull Royal Infirmary, Hull.

Results Women booked into prenatal care significantly earlier when referred by GP in comparison to directaccess with a significant difference in screening uptake of 49.5 and 42.7%, respectively. The ratio of uptakebetween first and second trimester screening was not significantly different.

Conclusions Further research on the new direct access method of referral is required, as it may have a rolein the uptake of prenatal screening for Down syndrome. More time is needed to show a definitive effect.Copyright 2011 John Wiley & Sons, Ltd.

KEY WORDS: Down syndrome; prenatal care; first trimester screening; serum screening

INTRODUCTION

Down syndrome can be diagnosed prenatally using inva-sive tests in the form of amniocentesis or chorionic villussampling. However, both are associated with a risk ofmiscarriage and, therefore, only performed if the preg-nancy is considered to be at high risk for chromosomalabnormalities (Tabor et al., 2009). High risk pregnanciesfor Down syndrome can be determined by first and sec-ond trimester screening tests. The triple test is used inthe second trimester, measuring the levels of free betahuman chorionic gonadotrophin (free β-hCG), alpha-fetoprotein (α-FP) and serum unconjugated estriol (uE3),and has been shown to have a detection rate of 65–70%(false-positive rate of 5%) for Down syndrome (Nico-laides, 2011). The addition of inhibin A with the tripletest markers, collectively known as the ‘quadruple test’,further improves the detection rate to 70–75% (false-positive rate of 5%) (Nicolaides, 2011). As these testsare only available in the second trimester, the decisionof invasive testing or the termination of pregnancy mayhave to be delayed accordingly. First trimester screeningfor Down syndrome is now becoming widely available.Screening in the first trimester commonly involves the

*Correspondence to: Stephen W. Lindow, Academic Departmentof Obstetrics and Gynaecology, Women and Children’s Hospital,Hull Royal Infirmary, Anlaby Road, Hull, East Yorkshire HU32JZ, UK. E-mail: stephen.lindow@hey.nhs.uk

use of ultrasonographic nuchal translucency (NT) mea-surements in addition to the maternal serum markers,pregnancy-associated plasma protein-A (PAPP-A) andβ-hCG, collectively known as the ‘combined test’. Thedetection rates of the combined test are 85–95% (5%false-positive rate) (Nicolaides, 2011). However, detec-tion rates have been shown to decline with increasingweeks of gestation (Cuckle et al., 1999). This is due tothe level of PAPP-A in trisomic and euploid pregnan-cies, with the optimal performance of the test seen inearlier gestations, where the greatest difference betweenthe two types of pregnancies is seen (Wright et al., 2010;Nicolaides, 2011). The combined test is therefore carriedout within the first trimester between 11 to 13 weeksand 6 days of gestation as recommend by the NationalInstitute of Clinical Excellence (NICE, 2008).

Previously, it had been shown by Gidiri et al. that theuptake of Down syndrome screening was declining inHull and East Yorkshire from a maximum of 82.6% in1993 to 41.4% in 2005, when only the triple test wasavailable (Gidiri et al., 2007). Another study based onthe population of Northern England shows a plateauingeffect in uptake to a similar level of around 40% forthe same period (Irving et al., 2008). The reasons forthe low uptake percentages are not apparent, and rather,the choices surrounding prenatal screening can be seento be complex and individual. Gidiri et al. suggest achange in women’s perceptions about screening forthe decline in uptake and further suggest that thereduction in uptake of screening is in part due to younger

Copyright 2011 John Wiley & Sons, Ltd. Received: 27 February 2011Revised: 5 June 2011

Accepted: 7 June 2011Published online: 3 August 2011

986 T. S NAWAZ et al.

women opting not to be screened (Gidiri et al., 2007).Nevertheless, a definitive cause to the change in trend isnot yet apparent.

Prenatal care for the majority of women often doesnot begin until the second trimester, and it has beenhighlighted that earlier referral is essential to gainfull advantage of these new screening methods (Benn,2002). Recognising the need for such change, the UKDepartment of Health in 2007 published the ‘MaternityMatters’ guidance document outlining four key nationalchoice guarantees (Department of Health, 2007). Onesuch choice guarantee was the option of how to accessmaternity care. The concept behind this was to givewomen and their partners the choice to go straight intomidwife led care or via their general practitioner (GP).The choice of self-referral into local midwifery serviceswas intended to speed up and enable earlier access toprenatal care.

The Hull and East Yorkshire NHS Trust maternityservices are provided by The Women & Children’sHospital, Hull. In October 2009, a direct access tomidwives referral system was launched, encouragingpregnant women to book directly with the midwife ratherthan with their GP. The effect of this service in recruitingwomen earlier into prenatal care and subsequent firsttrimester screening is yet unknown. Therefore, the aimof this study was to compare the uptake of Downsyndrome screening by women following referral by GPand direct access modes.

METHODS

This is a retrospective audit of referral methods intoprenatal care identified using the Women and Chil-dren’s Hospital Protos database and linkage to the HullRoyal Infirmary (HRI) Clinical Biochemistry Labora-tory database using patient identifier numbers to matchscreening test data for Down syndrome screening uptakefor 2010.

The population of women in the Hull and EastYorkshire region of the UK who booked for prenatalcare from 1 January to 31 December 2010 was studied.All women were offered an early ultrasound scan toaccurately determine gestational age. The combined test(NT plus PAPP-A and free β-hCG) was offered to allwomen booking in the first trimester (11 to 13 weeksand 6 days of gestation). Maternal serum screening (thetriple test—maternal serum estriol, free β-hCG and α-FP—or quadruple test including inhibin A) was offeredto all women who booked in the second trimester(between 14 and 20 weeks of gestation). All screeningtest analyses for the region were recorded by the HRIClinical Biochemistry Laboratory. The total number ofwomen screened using the first and second trimestertests in 2010 as well as the individual patient identifiernumber attributed to each woman when booking intoprenatal care were extracted from this database andstored on an Excel spread sheet.

The total number of women booking for prenatal carein 2010 was recorded by the Protos database at the

Women and Children’s Hospital, Hull. The variablesextracted from this database included the patient iden-tifier number, date of birth, method of referral, date ofbooking, gestational age at initial assessment, gravidaand parity. Maternal age at booking was calculated usingthese data. The method of referral was divided into ‘GP’,‘direct access’ or ‘other’. All women who booked byGP were included in the ‘GP’ category. Women book-ing directly into midwife led prenatal care were includedin the ‘direct access’ category. Women booking by theaccident and emergency department, voluntary servicesor other methods were included in the ‘other’ category.

The screening data were linked to the booking databy matching the patient identifier number from eachdata set, as this was the only common variable to each.This allowed the women undergoing screening to bematched to their referral method as shown in Figure 1.Women who could not be matched due to the lackof referral method or patient identifier number wereexcluded (Figure 1).

The private screening service data were accessed forthe 2010 study period to ensure that all women withinthe Hull and East Yorkshire region were incorporated inthe study. Twelve women were identified by postcode.However, these women were later excluded as noreferral method was available, and therefore, the abilityto match them to the appropriate referral mode was notpossible. All data were analysed using the SPSS v17statistical package.

RESULTS

Taking into consideration the numbers excluded, thetotal number of prenatal bookings for the 2010 studyperiod for which the method of referral and patientidentifiers were available was 6250. Of these, 62.3%(n = 3891) were referred by the GP and 37.1% (n =2318) by direct access (Table 1). Some women [0.6%(n = 41)] were excluded, as they did not fall within theabove methods of referral, that is they fell within the‘other’ category of referral.

Table 1 shows that the mean gestational age of womenbooking into prenatal care when referred by GP anddirect access was 10.2 and 10.9 weeks, respectively.This difference was shown to be statistically significant(T = −4.997, p ≤ 0.0001). Mean age at booking wasshown not to be significantly different between bookingmethods [(T = −1.2, p = not significant (NS)], nor wasmean gravidity and parity (Mann–Whitney U test, p =NS).

The trend in the method of referral and consequentbookings into prenatal care over the 2010 study periodis shown in Figure 2 (chi-squared test = 452.03, p <0.0001). In January 2010, 88.6% of women who bookedinto prenatal care were referred by GP compared with11.4% by direct access. GP booking referrals are shownto decline over the year and direct access increase. Asof December 2010, women were being referred andbooked into prenatal care almost equally by GP anddirect access, 50.5 and 49.5%, respectively (Figure 2).

Copyright 2011 John Wiley & Sons, Ltd. Prenat Diagn 2011; 31: 985–989.DOI: 10.1002/pd

DIRECT ACCESS MIDWIFERY BOOKING FOR PRENATAL CARE 987

Figure 1—Diagram showing the sources of data and the number of records obtained once databases were linked

Table 1—Characteristics of total bookings for each method of referral

Method of referralTotal bookings,

n (%)aMean (SD) gestationalage at booking, (w )∗

Mean (SD) age atbooking, (y)

Mean, mode,(gravidity range)

Mean, mode,(parity range)

General practitioner 3891 (62.3) 10.2 (4.86) 27.5 (5.99) 2.3,1, (0–12) 0.8, 0, (0–8)Direct access 2318 (37.1) 10.9 (5.96) 27.7 (5.93) 2.4, 1, (0–16) 0.8, 0, (0–9)

a Forty-one women excluded as not matching referral criteria.∗ T = −4.997, p ≤ 0.0001.

Screening uptake by referral method

Of the total number of women referred by GP,49.5% (n = 1927) underwent screening in comparisonto 42.7% (n = 990) of direct access referrals (Table 2).The difference in uptake between the two groups wasshown to be statistically significant (Chi-squared test =27.09, p < 0.0001).

As a result, 85.4% (n = 1645) of women screenedwhen referred by GP have a first trimester test (combinedtest) and 14.6% (n = 282) a second trimester test (tripleor quad test). Similarly, 86.2% (n = 853) of womenreferred by direct access have a first trimester test and13.8% (n = 137) a second trimester test (Chi-squaredtest = 0.56, p = NS). The mean gestational age of GPreferred screened women was 9.4 weeks, compared witha gestational age of 9.5 weeks for direct access-referredscreened women (T = −0.3, p = NS). Mean gravidityand parity were the same in relation to the method ofreferral (Mann–Whitney U test, p = NS).

DISCUSSION

The combined screening test for Down syndrome isperformed within the first trimester. The benefit of this

early detection test is that it allows women to makechoices regarding the outcome of a high risk resultsooner. The test must be backed up with an invasive testto make a definitive diagnosis of Down syndrome. CVS,although carries an increased risk of miscarriage afterprocedure, can be performed between 11 and 14 weeksand is the usual test offered to women with high riskscreening results. However, as the combined test is onlysensitive in the first trimester, it is essential that womenbook into prenatal care early, that is before 13 weeks and6 days of gestation. The predominant referral methodinto prenatal care for pregnant women has been by GP.Delays in women accessing this service would mean thatthe advantage of an early test is lost.

We demonstrate that GPs had a higher number ofreferrals and that these women were booking approx-imately half a week earlier compared with direct access.The clinical significance of this result may thereforeindicate that the advantage entailed in early prenatalscreening for Down syndrome is greater to those womenwho choose to be referred by GPs. Neither gravidity norparity or maternal age was shown to be significantlydifferent between the two groups of referrals.

Direct access is still a new concept, and this maytherefore explain the lower numbers of referrals by thismethod. Furthermore, it is uncertain whether knowledgeabout the direct access service is on par with that of the

Copyright 2011 John Wiley & Sons, Ltd. Prenat Diagn 2011; 31: 985–989.DOI: 10.1002/pd

988 T. S NAWAZ et al.

Figure 2—Percentage of women referred by General Practitioner (GP) and direct access (DA) booking into prenatal care per month in 2010(chi-squared test = 452.03, p < 0.0001)

Table 2—Characteristics of women who accepted screening (n = 2917) categorised by their methods of referral

Method of referral

Totalbooking,n (%)a

Screeninguptake, n

(%)∗

First trimestertest uptake,

n (%)

Secondtrimester

test uptake,n (%)

Mean, mode, (rangeof gestational

age atbooking) (w )

Mean, mode,(gravidarange)

Mean, mode,(parityrange)

General practitioner 3891 (62.3) 1927 (49.5) 1645 (85.4) 282 (14.6) 9.4, 10, (0–21) 2.2, 1, (0–9) 0.7, 0, (0–7)Direct access 2318 (37.1) 990 (42.7) 853 (86.2) 137 (13.8) 9.5, 10 (0–22) 2.3, 1, (0–13) 0.7, 0, (0–7)

Percentage uptake of first and second trimester tests for each method of referral also shown.a Forty-one women excluded as not matching referral criteria.∗ Chi-squared test = 27.09, p ≤ 0.0001.

traditional GP referral system, although extensive adver-tising of the new service was carried out throughoutthe year. The direct access referral system was devisedto give women more choice and control in their owncare, but it was also thought to provide an additionaladvantage of earlier access to prenatal care. A reason-able explanation therefore as to why women referredby direct access were found to book in later comparedwith GP referrals cannot be found. It would thus appearthat direct access is not achieving earlier bookings whencompared with previously implemented referral meth-ods. However, we speculate that women who chosedirect access are more in tune with a non-medical pat-tern of care and consequently are not going to opt forscreening as frequently as other women who chose theirGP as a referral route. Nonetheless, the national guide-line of booking women into prenatal care by 12 weeksand 6 days (NICE, 2008) is being met by both referralmethods.

The use of direct access has become more established,with the number of referrals rising over the courseof 2010. This change in trend may be a result ofthe advertising campaign implemented throughout theyear. Towards the end of 2010, women were referredalmost equally by direct access and GP. However, itis yet uncertain whether the use of direct access will

steadily increase with time or remain unchanged. Itmay therefore be deemed valuable to carry out quality-controlled regular audits to monitor this trend in referralrate, helping to validate its appropriateness.

The uptake of Down syndrome screening indicatethat the GP is more effective at referring women forscreening, as they had a statistically significant higherpercentage uptake compared with direct access. Never-theless, all women regardless of the method of refer-ral are counselled for Down syndrome screening bymidwives (i.e. all women taking up screening receivethe same information and support regarding screening).Whether GPs give any added benefit to women to uptakescreening is unknown. Interestingly, it is thought thata women’s own personal perspective with cultural andreligious influences and the knowledge of the conditionbeing screened for have a greater effect on the uptakeof screening rather than demographic factors (Chilakaet al., 2001; Gidiri et al., 2007). This is further sup-ported by our results, which indicated that gravidity andparity had no effect on screening uptake. A previousstudy carried out in the same region also demonstratedthat parity was not a factor effecting screening uptakeand that it retained a uniform pattern across the years(Gidiri et al., 2010). A meta-synthesis of nine studieslooking at pregnant women’s perception and decision

Copyright 2011 John Wiley & Sons, Ltd. Prenat Diagn 2011; 31: 985–989.DOI: 10.1002/pd

DIRECT ACCESS MIDWIFERY BOOKING FOR PRENATAL CARE 989

making about prenatal screening for Down syndromeindicate factors such as anxiety, views on abortion andperceptions of having a child with Down syndrometo play important roles in uptake of screening (Reidet al., 2009). In respect to anxiety, some women usedscreening uptake as a way of reducing anxiety and gain-ing reassurance about fetal health, whilst other womenhighlighted the potential anxiety provoked by screen-ing and subsequent wait for results as a deterrent toprenatal screening. Views on abortion were based onreligious and personal beliefs and values, with womenperceiving screening as pointless if abortion was nota feasible option (Reid et al., 2009). The authors con-clude that women’s decision regarding screening wereincumbent upon a range of expectations based on cur-rent images of future psychological states and ethicaldilemmas (Reid et al., 2009). Other studies indicate mis-carriage rate, Down syndrome risk estimate, motivation,support and employment status as factors implicated inpersonal choice of Down syndrome screening uptake(Asongu et al., 2010). The decision to accept Down syn-drome screening therefore appears to be multifactorial,involving a complex decision-making process.

Overall, the effect of direct access on Down syndromescreening has not been as large as expected with GPreferrals proving to have had a far greater impact onscreening rates.

Limitations of this study design include the lack ofcontrol for possible bias and potential confounding fac-tors as well as the reliance on the accuracy of datainput. The Protos database used within the study wasliable to human error, as each type of referral methodand corresponding variables were entered by hand. Anattempt to overcome this was made by excluding incom-plete records such as those without referral methods orrelated patient identifier numbers. The Clinical Biochem-istry Laboratory screening database processed samplesin the same laboratory with a comprehensive and con-temporaneously recorded set of data.

FUTURE PERSPECTIVE

As the new first trimester Down syndrome test becomesreadily available, its limiting factor would be the lackof early bookings. The new direct access service is stillin its early years. Whether it will prove to become morepopular and facilitate a greater number of early referralsand subsequent bookings into prenatal care in future isyet unknown. It is also important to acknowledge themany factors influencing the uptake of screening. Theimportant aspect of personal choice means that thereis a place for many models of care to exist within thesame system. Further comparisons once the direct accessservice has become well established would be beneficial

to help clarify its role within the prenatal booking andscreening programme.

SUMMARY POINTS

The combined test is offered to women in their firsttrimester. A new direct access service encouragingwomen to book early into prenatal care directly withmidwives was launched in Hull and East Yorkshirein late 2009. Compared with GP referrals, womenwere booking later into care when referred by directaccess. Fewer women were referred to Down syndromescreening with this new service in comparison to GP-referred bookings. No significant difference was foundbetween the uptake of first and second trimester testsbetween the two methods of referrals. A reasonableexplanation for the lack of earlier bookings for directaccess is yet to be found. Direct access has become morepopular over the course of 2010, and further research ofits role in first trimester Down syndrome screening isrequired.

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Copyright 2011 John Wiley & Sons, Ltd. Prenat Diagn 2011; 31: 985–989.DOI: 10.1002/pd