Women who are at high risk of developing gestational diabetes (GDM) on the basis of their age, having BMI ≥30 kg/m², South Asian ethnicity, previous macrosomic baby of 4.5 kg or more, personal prior history or close family history of diabetes should be screened at 26–28 weeks with a glucose tolerance test (GTT) [16]. If the GTT is abnormal, referral should be made to the multidisciplinary obstetric-diabetic clinic. Dietary assessment and modification, use of oral hypoglycaemic agents (Metformin) and/or insulin may be necessary to ensure normo glycaemia.

Women should have a risk assessment early in pregnancy based on their age, parity, family and personal history of thromboembolism, medical history and current health to assess their risk of thrombosis during pregnancy (Table 9.3) [17]. A decision about whether thromboprophylaxis should be offered during or after pregnancy can be made on this assessment. Factors occurring during pregnancy may also influence decisions about the need for short-term thromboprophylaxis, e.g., if ovarian hyperstimulation has been triggered, or the woman is hospitalised, immobile or unwell with a pyrexia.

Women with twin pregnancies have at least double the incidence of gestational hypertension and pre-eclampsia as those with singleton pregnancies [18]. In a cohort study of multiple pregnancies conceived either spontaneously or after ART (either ovulation induction alone or IVF), those women who received ART were twice as likely to develop preeclampsia, after adjustment for age and parity [19].

Hypertensive disorders occur in about 10 % of pregnancies and are responsible for a third of severe maternal morbidity, as well as many maternal deaths [14]. Chronic hypertension is present in about 1–2 % of pregnant women with rates increasing as maternal age increases [10, 11]. Chronic hypertension may be primary (essential) in approximately 90 % of cases with the remaining 10 % secondary to one or more underlying diseases such as renal disease, collagen vascular disease, endocrine disorders, or coarctation of the aorta. Pre-existing hypertension is a well-recognised risk factor for pre-eclampsia and all its associated sequaelae [14]. There are no specific studies comparing the incidence of hypertensive complications in women with and without pre -existing hypertension who have conceived following ART.

Women with polycystic ovarian syndrome (PCOS) more often need ART to achieve pregnancy than women without this diagnosis; 13.7 % in a large Swedish study of 3787 births to women with PCOS, compared to a background rate of 1.5 % in more than one million women without PCOS [21]. The study also found these women were almost twice as likely to be obese. There were strong associations between PCOS and pre-eclampsia (adjusted odds ratio 1.45, with 95 % confidence interval 1.24–1.69) and between PCOS and gestational diabetes (adjusted odds ratio 2.32, with 95 % confidence interval 1.88–2.88) [21]. Adjustments in the odds ratios quoted here had been made for maternal age, parity, BMI, ART, smoking, year of delivery and years of education.

Another study looked at the adverse pregnancy outcomes in obese and non-obese women with PCOS who underwent ART, compared to obese and non-obese controls, who had ART for tubal factor infertility [22]. As this was an Asian population, obesity was defined as BMI more than 25 kg/m². No differences in the incidence of pregnancy-induced hypertension were found between the 4 groups; however, it was the obese women from PCOS and control groups who had the highest incidence of gestational diabetes (10.5 % and 8.6 %, respectively) [22].

It is important to check thyroid function and correct clinical hypothyroidism or hyperthyroidism prior to ART. Derangement of thyroid function is likely to be a major contributor to subfertility. However, it is also apparent that subclinical hypothyroidism (i.e., elevated thyroid stimulating hormone levels in the presence of normal circulating free thyroxine and tri-iodothyronine levels) and the presence of thyroid antibodies are associated with adverse pregnancy outcomes. In a meta-analysis of women with subclinical hypothyroidism compared to those with normal thyroid function higher risks for pre-eclampsia (Odds Ratio 1.7, with 95 % confidence intervals 1.1–2.6) and perinatal mortality (Odds Ratio 2.7, with 95 % confidence intervals 1.6–4.7) were found [23]. Thyroid antibodies were associated with higher risks for miscarriage, recurrent miscarriage, preterm birth and maternal thyroiditis in the postpartum period [23].

Another systematic review looked at randomised controlled trials of levothyroxine versus placebo treatment for women with subclinical hypothyroidism or thyroid autoimmunity who were undergoing ART [24]. The conclusions (from 3 trials totalling 220 patients) were that levothyroxine treatment lowers miscarriage rate, increases live delivery rate, but no changes could be demonstrated in the incidence of pre-eclampsia [24].

Any woman with a chronic medical condition who is aiming to conceive with ART should be counselled about the likely effects of their condition on pregnancy outcome, the effects of pregnancy on their medical condition and they should have their drug medication reviewed for safety. A multidisciplinary approach may be required, as there can be a conflict of interest with respect to what may be best for the mother and what for the fetus. In these circumstances, skilled counselling about the safest and most sensible course is needed. For some conditions, multidisciplinary review may conclude that pregnancy is very hazardous; in which case, proceeding with ART would be unethical.

An example of inadequate pre-conceptual preparation was reported by the French Study Group for Oocyte Donation, who looked at the maternal and fetal outcomes of pregnancies achieved by oocyte donation in women with Turner’s Syndrome [25]. There were 93 patients in this study, of whom only 35 had undergone echocardiography or cardiac magnetic resonance imaging in preparation for ART and only 6 had documented aortic root diameters. Of the 82 women whose pregnancies continued beyond 20 weeks, 31 had hypertensive complications, including 4 cases of eclampsia. Two mothers died from aortic rupture, with evidence of aortic root dilatation. Almost a third of the babies were growth-restricted and there was one fetal death attributed to maternal eclampsia. Only 40 % of the reported pregnancies resulted in normal fetal and maternal outcomes.