Screening for gestational diabetes using risk factors is recommended in a healthy population. At the booking appointment, the following risk factors for gestational diabetes should be determined:

Women with any one of these risk factors should be offered testing for gestational diabetes. If she has type 2 diabetes, she will be treated as pregestational diabetes and does not need any screening for GDM.

1. Antenatal care NICE guideline no 62.

2. Diabetes in pregnancy NICE guideline CG63.

There is no evidence that passenger air travel increases the risk of pregnancy complications such as preterm labour, rupture of membranes or abruption. The radiation dose to the fetus from flying is not significant unless frequent long-haul air travel occurs in pregnancy. Body scanners that utilise ionising radiation for security checks do not pose a risk to mother or fetus from radiation exposure. Flights of more than 4 h of duration are associated with a small increase in the relative risk of venous thrombosis, but overall the absolute risk is very small. The presence of specific risk factors for thrombosis would be expected to increase the risk, and therefore a specific risk assessment should be made for thrombosis in pregnant women who are travelling by air. Specific measures that are likely to be of benefit are graduated elastic compression stockings for women who are pregnant and flying medium- to long-haul flights lasting more than 4 h and LMWH for those with significant risk factors such as previous thrombosis or morbid obesity. Low-dose aspirin should not be used in pregnancy for thromboprophylaxis associated with air travel.

1. http://​www.​rcog.​org.​uk/​files/​rcog-corp/​21.​5.​13SIP1AirTravel.​pdf

2. Civil Aviation Authority. Guidance for Health Professionals Information on assessing fitness to fly. http://​www.​caa.​co.​uk/​default.​aspx?​catid=​2497&​pagetype=​90

For women who have accepted intrapartum antibiotic prophylaxis (IAP), benzylpenicillin should be administered as soon as possible after the onset of labour and given regularly until delivery. Clindamycin should be administered to those women allergic to benzylpenicillin. It is recommended that 3 g intravenous benzylpenicillin be given as soon as possible after the onset of labour and 1.5 g 4-hourly until delivery. Clindamycin 900 mg should be given intravenously 8-hourly to those allergic to benzylpenicillin.

Green Top guideline no. 36 Early onset Group B streptococcal disease, 2012. http://​www.​rcog.​org.​uk/​files/​rcog-corp/​GTG36_​GBS.​pdf

Placental abruption is seen more often in gestational hypertensive disease, advanced maternal age, increasing parity, the presence of multiple gestations, polyhydramnios, chorioamnionitis, prolonged rupture of membranes, trauma and possibly thrombophilias. Potential preventable risk factors include maternal cocaine and tobacco use. Unexplained elevated maternal serum alpha-fetoprotein (MSAFP) levels in the second trimester are associated with pregnancy complications such as placental abruption.

The precise cause of abruption is unknown. Abruption arises from haemorrhage into the decidua basalis of the placenta, which results in the formation of haematoma and an increase in hydrostatic pressure leading to separation of the adjacent placenta. The resultant haematoma may be small and self-limited or may continue to dissect through the decidual layers. However, the bleeding may be in whole or in part concealed, if the haematoma does not reach the margin of the placenta and cervix for the blood loss to be revealed. Therefore the amount of revealed haemorrhage poorly reflects the degree of blood loss. The bleeding may infiltrate the myometrium resulting in the so-called Couvelaire uterus.

Ngeh N, Bhide A. Antepartum haemorrhage. Curr Obstet Gynaecol. 2006;16:79–83.

Most women in the UK will have a routine scan at 21–23 weeks (anomaly scan). The placenta will be low lying in some, necessitating a repeat scan later in pregnancy, typically at 34–36 weeks. The diagnosis of placental praevia is most commonly made on ultrasound examination. Up to 26 % of placentas are found to be low lying on ultrasound examination in the early second trimester. Several studies have demonstrated that unless the placental edge is at least reaching the internal cervical os at midpregnancy, placenta praevia at term will not be encountered. Transvaginal ultrasound is safe in the presence of placenta praevia and is more accurate than transabdominal ultrasound in locating the placental edge.

Ngeh N, Bhide A. Antepartum haemorrhage. Curr Obstet Gynaecol. 2006;16:79–83.

RCOG guidelines recommend that any women going to the operation theatre with known major placenta praevia should be attended by an experienced obstetrician and anaesthetist, with consultant presence available, especially if these women have previous uterine scars or an anterior placenta or are suspected to be associated with placenta accreta. Four units of crossmatched blood should be kept ready, even if the mother has never experienced vaginal bleeding. Delivery of women with placenta praevia should not be planned in units where blood transfusion facilities are unavailable. The choice of anaesthetic technique for caesarean sections is usually made by the anaesthetist conducting the procedure.

RCOG Green Top guideline – Placenta Praevia, Placenta Praevia Accreta and Vasa Praevia: Diagnosis and Management (Green-Top 27).

Pregnant women with complex social factors may need additional support to use antenatal care services.

Examples of complex social factors include: substance misuse, recent arrival as a migrant, asylum seeker or refugee status, difficulty speaking or understanding English, age under 20, domestic abuse, poverty and homelessness. The NICE guideline on pregnancy and complex factors describes how access to care can be improved, how contact with antenatal carers can be maintained, the additional support and consultations that are required and the additional information that should be offered to pregnant women with complex social factors.

NICE guideline 110, Pregnancy and complex social factors, September 2010.

Diabetes when uncontrolled can cause cardiac anomalies, like transposition of great vessels, ventricular septal defect, situs inversus, single ventricle and hypoplastic left heart. A four-chamber view of the fetal heart and outflow tracts should be offered as part of routine antenatal care. Hyperglycaemia is a toxic environment for the developing embryo, and the incidence of malformation is related to glucose control. This is why optimising glycaemic control prior to pregnancy is so important, as it may be too late to reduce the teratogenic effect of hyperglycaemia by the time of the first antenatal appointment.

1. Lambert K, Germain S. Pre-existing type I and type II diabetes in pregnancy. Obstet Gynecol Rep Med. 20(12):353–8.

2. Nice guideline no. 63 Diabetes in pregnancy. http://​www.​nice.​org.​uk/​guidance/​cg63/​resources/​guidance-diabetes-in-pregnancy-pdf

The risk of transmission of syphilis from mother to fetus is dependent on the stage of maternal infection and duration of fetal exposure. The transmission risk of early syphilis in pregnancy is up to 100 %, and 50 % of these pregnancies will result in preterm birth or perinatal death. Ten percent of infants born to women with late infection will be affected. Congenital syphilis is a multisystem infection which can result in stillbirth, neonatal death and long-term disability.

Diagnosis is by serology. Most cases of syphilis in pregnancy are detected through antenatal screening but syphilis must be considered in the differential diagnosis of women with genital ulceration in pregnancy and repeat syphilis testing should be performed. In the UK, an enzyme immunoassay, which has high sensitivity and specificity, is used for screening.

A positive enzyme immunoassay is confirmed by either a T. pallidum haemagglutination assay or T. pallidum particle agglutination assay. A non-treponemal test, either a Venereal Diseases Reference Laboratory test or reactive plasma reagin, is a quantitative assay used to monitor disease activity and treatment response.

Allstaff S, Wilson J. The management of sexually transmitted infections in pregnancy. Obstet Gynaecol. 2012;14:25–32.

Folic acid is recommended in all pregnant women to prevent neural tube defects. Folic acid at a dosage of at least 1 mg daily is recommended for women with sickle cell disease outside pregnancy in view of their haemolytic anaemia, which puts them at increased risk of folate deficiency. Folic acid 5 mg daily should be prescribed during pregnancy to reduce the risk of neural tube defect and to compensate for the increased demand for folate during pregnancy.

Management of sickle cell disease in pregnancy. Green-Top guideline no. 61. London: RCOG Press; 2011. Available at http://​www.​rcog.​org.​uk/​files/​rcog-corp/​GTG6111042013.​pdf

Neural tube defects, which are comprised of open spina bifida, anencephaly and encephalocele, complicate 1.5/1000 pregnancies in the UK. Periconceptional folic acid reduces the incidence of both occurrence and recurrence of neural tube defects. A Department of Health Expert Advisory Group has recommended that women with a history of neural tube defects should take 4 mg of folic acid preconceptionally and for the first eight weeks of pregnancy.

Royal College of Obstetricians and Gynaecologists. Periconceptional folic acid and food fortification in the prevention of neural tube defects. Scientific impact paper no. 4. London: RCOG Press; 2003. Available at http://​www.​rcog.​org.​uk/​files/​rcog-corp/​uploaded-files/​SIP_​No_​4.​pdf

All women require follow-up imaging if the placenta covers or overlaps the cervical os at 20 weeks of gestation. Women with a previous caesarean section require a higher index of suspicion as there are two problems to exclude: placenta praevia and placenta accreta. If the placenta lies anteriorly and reaches the cervical os at 20 weeks, a follow-up scan can help identify if it is implanted into the caesarean section scar. In cases of asymptomatic women with suspected minor praevia, follow-up imaging can be left until 36 weeks of gestation. In cases with asymptomatic suspected major placenta praevia or a question of placenta accreta, imaging should be performed at around 32 weeks of gestation to clarify the diagnosis and allow planning for third-trimester management, further imaging and delivery.

Royal College of Obstetricians and Gynaecologists. Placenta praevia, placenta praevia accreta and vasa praevia: diagnosis and management. Green-Top guideline no. 27. London: RCOG Press; 2011. Available at http://​www.​rcog.​org.​uk/​files/​rcog-corp/​GTG27PlacentaPra​eviaJanuary2011.​pdf

Risk factors for vasa praevia include placental anomalies such as a bilobed placenta or succenturiate lobes where the fetal vessels run through the membranes joining the separate lobes together, a history of low-lying placenta in the second trimester, multiple pregnancy and in vitro fertilisation, where the incidence of vasa praevia has been reported to be as high as one in 300. The reasons for this association are not clear, but disturbed orientation of the blastocyst at implantation, vanishing embryos and the increased frequency of placental morphological variations in in vitro fertilisation pregnancies have all been postulated.

1. RCOG Greentop guideline no. 27. Placenta praevia accreta and vasa praevia. https://​www.​rcog.​org.​uk/​globalassets/​documents/​guidelines/​gtg_​27.​pdf

2. Baulies S, et al. Prenatal ultrasound diagnosis of vasa praevia and analysis of risk factors. Prenat Diagn. 2007;27:595–9.

Indomethacin had profound effects on platelet and neutrophil functioning; cerebral, renal and mesenteric haemodynamics and fetal ductus arteriosus. All these are likely to have serious effects on the fetus. It is reported to cause constriction of the ductus arteriosus, reduced urine output and frequently oligohydramnios. In the neonate born after indomethacin exposure, the reported complications include pulmonary hypertension, persistent ductus arteriosus, necrotising enterocolitis, ileal perforation and intraventricular haemorrhage.

Tocolysis for women in preterm labour. RCOG Green Top guideline No 1B. http://​www.​rcog.​org.​uk/​files/​rcog-corp/​GTG1b26072011.​pdf

Smoking remains the single largest preventable cause of fetal and infant morbidity in the UK. Potential problems during pregnancy include ectopic pregnancy, miscarriage, placental complications, premature rupture of membranes, premature birth and fetal growth restriction. Counselling sessions are effective in pregnancy and lead to a reduction in the incidence of preterm birth and low birth weight. Maternal smoking has also been associated with an overall reduced incidence of pre-eclampsia. Smoking may only be reduced in those women aged 30 years and under without pregestational hypertension. Sudden infant death syndrome describes the sudden unexplained loss of life in the first year. Data from a number of trials suggest that maternal smoking increases the risk of sudden infant death syndrome by up to fourfold compared with controls, therefore implying that many cases may be preventable. The mechanism underlying this is unclear, but some studies have suggested that exposure to a hypoxic state in the womb may diminish the normal physiological response to hypoxia in the neonate.

Eastham R, Gosakan R. Smoking and smoking cessation in pregnancy. Obstet Gynaecol. 2010;12:103–9.

Clinicians should offer a single course of antenatal corticosteroids to women between 24 + 0 and 34 + 6 weeks of gestation who are at risk of preterm birth. It is associated with a significant reduction in rates of neonatal death, RDS and intraventricular haemorrhage.

Betamethasone 12 mg given intramuscularly in two doses and dexamethasone 6 mg given intramuscularly in four doses are the steroids of choice to enhance lung maturation. A rescue course of two doses of 12 mg betamethasone or four doses of 6 mg dexamethasone should only be considered with caution in those pregnancies where the first course was given at less than 26 + 0 weeks of gestation and another obstetric indication arises later in pregnancy.

Antenatal corticosteroids to reduce neonatal morbidity and mortality. RCOG Green Top guideline no. 7.

External cephalic version (ECV) is the manipulation of the fetus, through the maternal abdomen, to a cephalic presentation. ECV reduces the caesarean section rate by lowering the incidence of breech presentation (RR 0.55,95 % CI 0.33–0.91, risk difference 17 %, NNT 6). Provision of an ECV service also reduces the caesarean section rates for breech presentation. This reduction is in spite of a twofold increase in intrapartum caesarean sections for successfully turned babies, when compared with babies that were not breech at term.

Women should be counselled that, with a trained operator, about 50 % of ECV attempts will be successful but this rate can be individualised for them. Results vary from 30 % up to 80 % in different series. Race, parity, uterine tone, liquor volume, engagement of the breech and whether the head is palpable and the use of tocolysis all affect the success rate.

http://​www.​rcog.​org.​uk/​files/​rcog-corp/​uploaded-files/​GT20aExternalCep​halicVersion.​pdf

Offer women with twin and triplet pregnancies a first-trimester ultrasound scan when crown-rump length measures from 45 mm to 84 mm (at approximately 11 to 13 + 6 weeks) to estimate gestational age, determine chorionicity and screen for Down syndrome (ideally, these should all be performed at the same scan).

Use the largest baby to estimate gestational age in twin and triplet pregnancies to avoid the risk of estimating it from a baby with early growth pathology.

NICE guideline 129. Multiple pregnancy. 2011. http://​www.​nice.​org.​uk/​guidance/​cg129

Caregivers should be aware of the higher incidence of anaemia in multiple pregnancies as compared to singleton pregnancies. Perform a full blood count at 20–24 weeks to identify women with twin and triplet pregnancies who need early supplementation with iron or folic acid, and repeat at 28 weeks as in routine antenatal care.

Booking blood test is offered to all pregnant women for screening for anaemia.

1. NICE guideline no 69 Multiple pregnancy, http://​www.​nice.​org.​uk/​guidance/​cg129

2. NICE guideline antenatal care.

Inform women with uncomplicated dichorionic twin pregnancies that elective birth from 37 weeks 0 days does not appear to be associated with an increased risk of serious adverse outcomes and that continuing uncomplicated twin pregnancies beyond 38 weeks 0 days increase the risk of fetal death.

For women who decline elective birth, offer weekly appointments with the specialist obstetrician. At each appointment, offer an ultrasound scan, and perform weekly biophysical profile assessments and fortnightly fetal growth scans.

NICE guideline no 129, Multiple pregnancy. http://​www.​nice.​org.​uk/​guidance/​cg129

If a woman with a twin or triplet pregnancy presents after 14 weeks 0 days, determine chorionicity at the earliest opportunity by ultrasound using all of the following:

If it is not possible to determine chorionicity by ultrasound at the time of detecting the twin or triplet pregnancy, seek a second opinion from a senior ultrasonographer or offer the woman referral to a healthcare professional who is competent in determining chorionicity by ultrasound scan as soon as possible.

If it is difficult to determine chorionicity, even after referral (e.g. because the woman has booked late in pregnancy), manage the pregnancy as monochorionic until proved otherwise.

NICE guideline no 129, Multiple pregnancy. http://​www.​nice.​org.​uk/​guidance/​cg129