A 2008 case control study from Norway [20] found that the OR for VTE with pregnancy following ART was 4.3 (95 % CI: 2.0–9.4). This risk is further increased in women with ovarian hyper-stimulation syndrome (OHSS).

Women with a personal or family history of venous thrombo-embolism should be screened for inherited and acquired thrombophilia. Women with a history of previous venous thromboembolism or asymptomatic inherited or acquired thrombophilias are at a greater risk of venous thrombosis in pregnancy [21]. Those with previous venous thrombosis are also at a risk of pulmonary embolism in pregnancy which remains one of the leading causes of maternal mortality in the UK [22]. Those with a positive screen need specialist advice and may need thromboprophylaxis during early pregnancy [10]. Some women may be on long-term oral anti-coagulation with warfarin. The risks are that of warfarin embryopathy if the fetus is exposed, particularly in the first trimester. Warfarin should be substituted by LMWH before commencing fertility treatment. If this is not possible, stopping anticoagulation before the sixth week after conception may minimize the risk to the fetus [22].

Women proceeding to fertility treatment on anticoagulation should have an anaesthetic review prior to surgical procedures such as oocyte retrieval. In women on oral anticoagulants, anticoagulation should be temporarily replaced by LMWH and stopped for an appropriate duration prior to the procedure in conjunction with a haematologist.

Ovarian Hyperstimulation Syndrome (OHSS) is an iatrogenic complication of controlled ovarian stimulation for IVF and occurs in about 3–8 % of these women [23]. It is triggered by endogenous or exogenous HCG and its effects mediated by the vascular endothelial growth factor. It is a potentially lethal condition, characterised by a third space fluid shift with intravascular volume depletion leading to electrolyte imbalance, haemoconcentration and compromise of vital systems. OHSS may pose a greater risk in women with pre existing conditions such as cardiac, renal and thrombo-embolic disease. IVF treatment protocols should be suitably tailored to avoid this complication.

Pre-conception advice is not the same as prenatal care. Although the benefits appear obvious and logical, formal evidence of its benefit is difficult to come by.

A recent systematic review and meta-analysis by Wahabi et al [24] showed the impact of preconception care. This usually involved glycaemic control (with Insulin if necessary), self-monitoring of blood glucose levels and dietary advice. They concluded that pre-conception care is effective in reducing congenital malformations, RR:0.25 (95 % CI 0.15–0.42), NNT = 17 (95 % CI 14–24), preterm delivery, RR: 0.70 (95 % CI 0.55–0.90), NNT = 8 (95 % CI 5–23) and perinatal mortality RR: 0.35 (95 % CI 0.15–0.82), NNT = 32 (95 % CI 19–109). Preconception care lowers HbA1c in the first trimester of pregnancy by an average of 2.43 % (95 % CI 2.27–2.58). Women who received preconception care booked earlier for antenatal care by an average of 1.32 weeks (95 % CI 1.23–1.40). Hypoglycemia was, however, more common with pre-conceptional care group (RR = 1.51, 95 % CI: 1.15–1.99).

A Cochrane review [25] concluded that Folic acid, alone or in combination with vitamins and minerals, prevents NTDs but does not have a clear effect on other birth defects. Another Cochrane review [26] explored the effectiveness of preconception counselling for women with epilepsy, measured by a reduction in adverse pregnancy outcome in both mother and child. This review found no studies suitable for inclusion. Currently, a revision of this Cochrane review is in progress.