Table 2. Summary of invasive and non-invasive prenatal tests.

Rh: Rhesus factor, L/S ratio: Lecithin/ Sphingomyelin ratio, TORCH infections: Toxoplasmosis, Other (syphilis, varicella-zoster, parvovirus B19), Rubella, Cytomegalovirus and Herpes infections, MSAFP: Maternal serum alpha-fetoprotein, PAPP-A: Pregnancy-associated plasma protein A, IUGR: Intrauterine growth restriction, SGA: Small for gestational age, cffDNA: Cell-free foetal DNA, USG: Ultrasonography, CRL: Crown-rump length, MSD: Musculoskeletal disorders.

References	Name	Testing sample	Timing of test from	Abnormality screened/ diagnosed/ evaluated
Jindal, Sharma and Chaudhary. [5]	Amniocentesis	Amniotic fluid	15 weeks gestation to delivery	Sex-linked disorders, Rh isoimmunisation, inborn errors of metabolism, L/S ratio, TORCH infections, neural tube defects
Jindal et al. [5]	Chorion biopsy	Tissue aspirate of chorionic villi	10 to 14 weeks of gestation	Genetic diseases like Down syndrome, cystic fibrosis, sickle cell anaemia and sex-linked disorders
Deka et al. [8]	Fetoscopy	Foetal blood or tissue sample	17 to 20 weeks of gestation	Sickle cell anaemia, haemophilia, Tay Sachs disease, neural tube defects
Jindal et al. [5], Peddi et al. [9]	Cordocentesis	Foetal blood from umbilical cord	20 to 28 weeks of gestation	Haematological, inborn infectious disease, histopathologic analysis, metabolic assay, intrauterine growth retardation
Antsaklis et al. [10]	MSAFP	Maternal blood	14 weeks to 32 weeks of gestation	Neural tube defects, omphalocele, gastroschisis, down syndrome
Shiefa et al. [11]	Chorionic gonadotropin	Maternal urine or blood sample	8-10 weeks of gestation to delivery	Confirmation of pregnancy, ectopic pregnancy, trophoblastic disease, placental site trophoblastic disease
Betz and Fane. [12]	Unconjugated oestriol	Maternal blood serum and plasma	12 weeks of gestation till term	Trisomy 21, trisomy 18, foetal growth restriction, foetal demise, pregnancy loss, predicting the onset of labour
Shiefa et al. [11],  Fruscalzo et al. [13]	PAPP-A	Maternal blood serum	10 to 14 weeks of gestation	Down syndrome, stillbirth, IUGR, SGA, preeclampsia
Pös, Budiš and Szemes. [14], Bedei et al. [15]	cffDNA	Maternal blood	Ten weeks of gestation till delivery	Down syndrome, Edward syndrome, Patau syndrome, haemoglobinopathies, phenylketonuria, Rh status
Ulrich and Dewald. [16]	USG	NIL	10-13 weeks of gestation till delivery	Foetal viability, CRL, MSD, gross foetal abnormality, chromosomal abnormalities, Intertwin membrane, placental abnormality
	Radiography	NIL	14 weeks of gestation till delivery	Diagnosis of pregnancy, foetal maturity, pelvimetry, congenital malformations